diff --git a/docs/example-projects/using-garden-in-ci.md b/docs/example-projects/using-garden-in-ci.md
index 4e5d360091..aaa199c6b6 100644
--- a/docs/example-projects/using-garden-in-ci.md
+++ b/docs/example-projects/using-garden-in-ci.md
@@ -44,7 +44,7 @@ name: ci-demo-project
 environments:
   ...
   - name: preview
-    defaultNamespace: ${project.name}-${local.env.CIRCLE_BRANCH || local.username}
+    defaultNamespace: preview-${local.env.CIRCLE_BRANCH || local.username}
 providers:
   - name: kubernetes
     environments: [preview]
diff --git a/docs/reference/config.md b/docs/reference/config.md
index 426961138f..22fbfb21bc 100644
--- a/docs/reference/config.md
+++ b/docs/reference/config.md
@@ -37,27 +37,13 @@ environments:
   - # The name of the environment.
     name:
 
-    # Control if and how this environment should support namespaces. If set to "optional" (the default), users can
-    # set a namespace for the environment. This is useful for any shared environments, e.g. testing and development
-    # environments, where namespaces separate different users or code versions within an environment. Users then
-    # specify an environment with `--env <namespace>.<environment>`, e.g. `--env alice.dev` or
-    # `--env my-branch.testing`.
+    # Set the default namespace to use. This can be templated to be user-specific, or to use an environment variable
+    # (e.g. in CI).
     #
-    # If set to "required", this namespace separation is enforced, and an error is thrown if a namespace is not
-    # specified with the `--env` parameter.
-    #
-    # If set to "disabled", an error is thrown if a namespace is specified. This makes sense for e.g. production or
-    # staging environments, where you don't want to split the environment between users or code versions.
-    #
-    # When specified, namespaces must be a valid DNS-style label, much like other identifiers.
-    namespacing: optional
-
-    # Set a default namespace to use, when `namespacing` is `required` or `optional`. This can be templated to be
-    # user-specific, or to use an environment variable (e.g. in CI).
-    #
-    # If this is set, users can specify `--env <environment>` and skip the namespace part, even when `namespacing` is
-    # `required` for the environment.
-    defaultNamespace:
+    # You can also set this to `null`, in order to require an explicit namespace to be set on usage. This may be
+    # advisable for shared environments, but you may also be able to achieve the desired result by templating this
+    # field, as mentioned above.
+    defaultNamespace: default
 
     # Flag the environment as a production environment.
     #
@@ -232,39 +218,17 @@ environments:
   - name: "dev"
 ```
 
-### `environments[].namespacing`
-
-[environments](#environments) > namespacing
-
-Control if and how this environment should support namespaces. If set to "optional" (the default), users can
-set a namespace for the environment. This is useful for any shared environments, e.g. testing and development
-environments, where namespaces separate different users or code versions within an environment. Users then
-specify an environment with `--env <namespace>.<environment>`, e.g. `--env alice.dev` or
-`--env my-branch.testing`.
-
-If set to "required", this namespace separation is enforced, and an error is thrown if a namespace is not
-specified with the `--env` parameter.
-
-If set to "disabled", an error is thrown if a namespace is specified. This makes sense for e.g. production or
-staging environments, where you don't want to split the environment between users or code versions.
-
-When specified, namespaces must be a valid DNS-style label, much like other identifiers.
-
-| Type     | Default      | Required |
-| -------- | ------------ | -------- |
-| `string` | `"optional"` | No       |
-
 ### `environments[].defaultNamespace`
 
 [environments](#environments) > defaultNamespace
 
-Set a default namespace to use, when `namespacing` is `required` or `optional`. This can be templated to be user-specific, or to use an environment variable (e.g. in CI).
+Set the default namespace to use. This can be templated to be user-specific, or to use an environment variable (e.g. in CI).
 
-If this is set, users can specify `--env <environment>` and skip the namespace part, even when `namespacing` is `required` for the environment.
+You can also set this to `null`, in order to require an explicit namespace to be set on usage. This may be advisable for shared environments, but you may also be able to achieve the desired result by templating this field, as mentioned above.
 
-| Type     | Required |
-| -------- | -------- |
-| `string` | No       |
+| Type     | Default     | Required |
+| -------- | ----------- | -------- |
+| `string` | `"default"` | No       |
 
 Example:
 
diff --git a/docs/reference/providers/kubernetes.md b/docs/reference/providers/kubernetes.md
index 57ee012920..f43a859ddf 100644
--- a/docs/reference/providers/kubernetes.md
+++ b/docs/reference/providers/kubernetes.md
@@ -62,9 +62,6 @@ providers:
     # A default hostname to use when no hostname is explicitly configured for a service.
     defaultHostname:
 
-    # Set a default username (used for namespacing within a cluster).
-    defaultUsername:
-
     # Defines the strategy for deploying the project services.
     # Default is "rolling update" and there is experimental support for "blue/green" deployment.
     # The feature only supports modules of type `container`: other types will just deploy using the default strategy.
@@ -314,10 +311,9 @@ providers:
     # Path to kubeconfig file to use instead of the system default. Must be a POSIX-style path.
     kubeconfig:
 
-    # Specify which namespace to deploy services to. Defaults to the environment namespace, if specified and enabled,
-    # otherwise the project name.
+    # Specify which namespace to deploy services to. Defaults to `<project name>-<environment namespace>`.
     #
-    # Note that the framework generates other namespaces as well with this name as a prefix.
+    # Note that the framework may generate other namespaces as well with this name as a prefix.
     namespace:
 
     # Set this to `nginx` to install/enable the NGINX ingress controller.
@@ -431,16 +427,6 @@ providers:
   - defaultHostname: "api.mydomain.com"
 ```
 
-### `providers[].defaultUsername`
-
-[providers](#providers) > defaultUsername
-
-Set a default username (used for namespacing within a cluster).
-
-| Type     | Required |
-| -------- | -------- |
-| `string` | No       |
-
 ### `providers[].deploymentStrategy`
 
 [providers](#providers) > deploymentStrategy
@@ -1467,9 +1453,9 @@ Path to kubeconfig file to use instead of the system default. Must be a POSIX-st
 
 [providers](#providers) > namespace
 
-Specify which namespace to deploy services to. Defaults to the environment namespace, if specified and enabled, otherwise the project name.
+Specify which namespace to deploy services to. Defaults to `<project name>-<environment namespace>`.
 
-Note that the framework generates other namespaces as well with this name as a prefix.
+Note that the framework may generate other namespaces as well with this name as a prefix.
 
 | Type     | Required |
 | -------- | -------- |
diff --git a/docs/reference/providers/local-kubernetes.md b/docs/reference/providers/local-kubernetes.md
index 68070d56c9..b1c4131c8b 100644
--- a/docs/reference/providers/local-kubernetes.md
+++ b/docs/reference/providers/local-kubernetes.md
@@ -58,9 +58,6 @@ providers:
     # A default hostname to use when no hostname is explicitly configured for a service.
     defaultHostname:
 
-    # Set a default username (used for namespacing within a cluster).
-    defaultUsername:
-
     # Defines the strategy for deploying the project services.
     # Default is "rolling update" and there is experimental support for "blue/green" deployment.
     # The feature only supports modules of type `container`: other types will just deploy using the default strategy.
@@ -397,16 +394,6 @@ providers:
   - defaultHostname: "api.mydomain.com"
 ```
 
-### `providers[].defaultUsername`
-
-[providers](#providers) > defaultUsername
-
-Set a default username (used for namespacing within a cluster).
-
-| Type     | Required |
-| -------- | -------- |
-| `string` | No       |
-
 ### `providers[].deploymentStrategy`
 
 [providers](#providers) > deploymentStrategy
diff --git a/examples/build-dependencies/garden.yml b/examples/build-dependencies/garden.yml
index 61c9652925..1f823e419b 100644
--- a/examples/build-dependencies/garden.yml
+++ b/examples/build-dependencies/garden.yml
@@ -4,7 +4,7 @@ name: build-dependencies
 environments:
   - name: local
   - name: remote
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/deployment-strategies/garden.yml b/examples/deployment-strategies/garden.yml
index be12b85818..39d959d9d8 100644
--- a/examples/deployment-strategies/garden.yml
+++ b/examples/deployment-strategies/garden.yml
@@ -5,7 +5,7 @@ environments:
   - name: local-default
   - name: local-blue-green
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
     # Default deployment strategy
   - name: local-kubernetes
diff --git a/examples/disabled-configs/garden.yml b/examples/disabled-configs/garden.yml
index b3e5d2cad7..6b57289b05 100644
--- a/examples/disabled-configs/garden.yml
+++ b/examples/disabled-configs/garden.yml
@@ -7,9 +7,9 @@ environments:
 providers:
   - name: local-kubernetes
     environments: [local]
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
   - name: kubernetes
     environments: [remote]
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
     # Replace these values as appropriate
     context: gke_garden-dev-200012_europe-west1-b_garden-dev-1
     defaultHostname: ${local.username}-disabled-configs.dev-1.sys.garden
diff --git a/examples/hadolint/garden.yml b/examples/hadolint/garden.yml
index f7679746a6..cea414aa23 100644
--- a/examples/hadolint/garden.yml
+++ b/examples/hadolint/garden.yml
@@ -3,7 +3,7 @@ name: demo-project
 environments:
   - name: local
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: hadolint
   - name: local-kubernetes
diff --git a/examples/hot-reload-post-sync-command/garden.yml b/examples/hot-reload-post-sync-command/garden.yml
index e2eadba9a4..5891509863 100644
--- a/examples/hot-reload-post-sync-command/garden.yml
+++ b/examples/hot-reload-post-sync-command/garden.yml
@@ -3,7 +3,7 @@ name: hot-reload-post-sync-command
 environments:
   - name: local
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/hot-reload/garden.yml b/examples/hot-reload/garden.yml
index 1bd84c1696..2480899bae 100644
--- a/examples/hot-reload/garden.yml
+++ b/examples/hot-reload/garden.yml
@@ -3,7 +3,7 @@ name: hot-reload
 environments:
   - name: local
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/kaniko/garden.yml b/examples/kaniko/garden.yml
index cb19d29442..5e8e289075 100644
--- a/examples/kaniko/garden.yml
+++ b/examples/kaniko/garden.yml
@@ -4,7 +4,7 @@ name: kaniko
 environments:
   - name: local
   - name: remote
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/kubernetes-secrets/garden.yml b/examples/kubernetes-secrets/garden.yml
index 2fe9209e5b..fc9ea6d9a0 100644
--- a/examples/kubernetes-secrets/garden.yml
+++ b/examples/kubernetes-secrets/garden.yml
@@ -3,7 +3,7 @@ name: kubernetes-secrets
 environments:
   - name: local
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/openfaas/garden.yml b/examples/openfaas/garden.yml
index bb434ff697..f2987ebc7c 100644
--- a/examples/openfaas/garden.yml
+++ b/examples/openfaas/garden.yml
@@ -3,7 +3,7 @@ name: openfaas
 environments:
   - name: local
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/project-variables/garden.yml b/examples/project-variables/garden.yml
index 62817b4d68..33695448ab 100644
--- a/examples/project-variables/garden.yml
+++ b/examples/project-variables/garden.yml
@@ -9,7 +9,7 @@ environments:
       # We only want one replica of each service when developing locally
       service-replicas: 1
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/remote-sources/garden.yml b/examples/remote-sources/garden.yml
index 79ec531ce0..7f00890cfd 100644
--- a/examples/remote-sources/garden.yml
+++ b/examples/remote-sources/garden.yml
@@ -8,7 +8,7 @@ sources:
 environments:
   - name: local
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/tasks/garden.yml b/examples/tasks/garden.yml
index 3a258f8882..cc00ef6fc9 100644
--- a/examples/tasks/garden.yml
+++ b/examples/tasks/garden.yml
@@ -3,7 +3,7 @@ name: tasks
 environments:
   - name: local
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/vote-helm/garden.yml b/examples/vote-helm/garden.yml
index 336b7fd40e..0733d2354f 100644
--- a/examples/vote-helm/garden.yml
+++ b/examples/vote-helm/garden.yml
@@ -3,7 +3,7 @@ name: vote-helm
 environments:
   - name: local
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/examples/vote/garden.yml b/examples/vote/garden.yml
index 68d7fba557..d9320828b5 100644
--- a/examples/vote/garden.yml
+++ b/examples/vote/garden.yml
@@ -4,7 +4,7 @@ environments:
   - name: local
   - name: remote
   - name: testing
-    defaultNamespace: ${project.name}-testing-${local.env.CIRCLE_BUILD_NUM || local.username}
+    defaultNamespace: testing-${local.env.CIRCLE_BUILD_NUM || local.username}
 providers:
   - name: local-kubernetes
     environments: [local]
diff --git a/garden-service/src/cli/cli.ts b/garden-service/src/cli/cli.ts
index f6ae3cb095..4caa8a4247 100644
--- a/garden-service/src/cli/cli.ts
+++ b/garden-service/src/cli/cli.ts
@@ -47,7 +47,7 @@ import {
   checkForUpdates,
   checkForStaticDir,
 } from "./helpers"
-import { defaultEnvironments, ProjectConfig } from "../config/project"
+import { defaultEnvironments, ProjectConfig, defaultNamespace } from "../config/project"
 import { ERROR_LOG_FILENAME, DEFAULT_API_VERSION, DEFAULT_GARDEN_DIR_NAME, LOGS_DIR_NAME } from "../constants"
 import stringify = require("json-stringify-safe")
 import { generateBasicDebugInfoReport } from "../commands/get/get-debug-info"
@@ -70,7 +70,7 @@ const GLOBAL_OPTIONS_GROUP_NAME = "Global options"
 
 export async function makeDummyGarden(root: string, gardenOpts: GardenOpts = {}) {
   const environments = gardenOpts.environmentName
-    ? [{ name: gardenOpts.environmentName, variables: {} }]
+    ? [{ name: gardenOpts.environmentName, defaultNamespace, variables: {} }]
     : defaultEnvironments
 
   const config: ProjectConfig = {
diff --git a/garden-service/src/config/project.ts b/garden-service/src/config/project.ts
index e8809ee5ea..40fa183f33 100644
--- a/garden-service/src/config/project.ts
+++ b/garden-service/src/config/project.ts
@@ -34,11 +34,13 @@ import { DEFAULT_API_VERSION, DOCS_BASE_URL } from "../constants"
 import { defaultDotIgnoreFiles } from "../util/fs"
 import { pathExists, readFile } from "fs-extra"
 import { resolve } from "path"
+import chalk = require("chalk")
 
 export const defaultVarfilePath = "garden.env"
 export const defaultEnvVarfilePath = (environmentName: string) => `garden.${environmentName}.env`
 
 // These plugins are always loaded
+export const defaultNamespace = "default"
 export const fixedPlugins = ["exec", "container"]
 
 export type EnvironmentNamespacing = "disabled" | "optional" | "required"
@@ -48,12 +50,9 @@ export interface ParsedEnvironment {
   namespace?: string
 }
 
-const defaultEnvironmentNamespacing: EnvironmentNamespacing = "optional"
-
 export interface EnvironmentConfig {
   name: string
-  namespacing?: EnvironmentNamespacing
-  defaultNamespace?: string
+  defaultNamespace: string | null
   providers?: ProviderConfig[] // further validated by each plugin
   varfile?: string
   variables: DeepPrimitiveMap
@@ -69,30 +68,14 @@ export const environmentNameSchema = () =>
 export const environmentSchema = () =>
   joi.object().keys({
     name: environmentNameSchema(),
-    namespacing: joi
-      .string()
-      .allow("disabled", "optional", "required")
-      .default("optional").description(dedent`
-        Control if and how this environment should support namespaces. If set to "optional" (the default), users can
-        set a namespace for the environment. This is useful for any shared environments, e.g. testing and development
-        environments, where namespaces separate different users or code versions within an environment. Users then
-        specify an environment with \`--env <namespace>.<environment>\`, e.g. \`--env alice.dev\` or
-        \`--env my-branch.testing\`.
-
-        If set to "required", this namespace separation is enforced, and an error is thrown if a namespace is not
-        specified with the \`--env\` parameter.
-
-        If set to "disabled", an error is thrown if a namespace is specified. This makes sense for e.g. production or
-        staging environments, where you don't want to split the environment between users or code versions.
-
-        When specified, namespaces must be a valid DNS-style label, much like other identifiers.
-      `),
     defaultNamespace: joiIdentifier()
+      .allow(null)
+      .default(defaultNamespace)
       .description(
         dedent`
-        Set a default namespace to use, when \`namespacing\` is \`required\` or \`optional\`. This can be templated to be user-specific, or to use an environment variable (e.g. in CI).
+        Set the default namespace to use. This can be templated to be user-specific, or to use an environment variable (e.g. in CI).
 
-        If this is set, users can specify \`--env <environment>\` and skip the namespace part, even when \`namespacing\` is \`required\` for the environment.
+        You can also set this to \`null\`, in order to require an explicit namespace to be set on usage. This may be advisable for shared environments, but you may also be able to achieve the desired result by templating this field, as mentioned above.
         `
       )
       .example("user-${local.username}"),
@@ -224,7 +207,7 @@ export interface ProjectResource extends ProjectConfig {
 export const defaultEnvironments: EnvironmentConfig[] = [
   {
     name: "local",
-    namespacing: defaultEnvironmentNamespacing,
+    defaultNamespace,
     providers: [
       {
         name: "local-kubernetes",
@@ -572,23 +555,19 @@ export async function pickEnvironment(config: ProjectConfig, envString: string)
  * Validates that the value passed for `namespace` conforms with the namespacing setting in `environmentConfig`,
  * and returns `namespace` (or a default namespace, if appropriate).
  */
-export function getNamespace(environmentConfig: EnvironmentConfig, namespace: string | undefined): string | undefined {
+export function getNamespace(environmentConfig: EnvironmentConfig, namespace: string | undefined): string {
   const envName = environmentConfig.name
 
-  if (namespace && environmentConfig.namespacing === "disabled") {
-    throw new ParameterError(
-      `Environment ${envName} does not allow namespacing, but namespace '${namespace}' was specified.`,
-      { environmentConfig, namespace }
-    )
-  }
-
   if (!namespace && environmentConfig.defaultNamespace) {
     namespace = environmentConfig.defaultNamespace
   }
 
-  if (!namespace && environmentConfig.namespacing === "required") {
+  if (!namespace) {
+    const envHighlight = chalk.white.bold(envName)
+    const exampleFlag = chalk.white(`--env=${chalk.bold("some-namespace.")}${envName}`)
+
     throw new ParameterError(
-      `Environment ${envName} requires a namespace, but none was specified and no defaultNamespace is configured.`,
+      `Environment ${envHighlight} has defaultNamespace set to null, and no explicit namespace was specified. Please either set a defaultNamespace or explicitly set a namespace at runtime (e.g. ${exampleFlag}).`,
       {
         environmentConfig,
       }
diff --git a/garden-service/src/docs/generate.ts b/garden-service/src/docs/generate.ts
index 473c4ea92b..eb60e43d7f 100644
--- a/garden-service/src/docs/generate.ts
+++ b/garden-service/src/docs/generate.ts
@@ -17,6 +17,7 @@ import { keyBy } from "lodash"
 import { writeFileSync } from "fs-extra"
 import { renderModuleTypeReference, moduleTypes } from "./module-type"
 import { renderProviderReference } from "./provider"
+import { defaultNamespace } from "../config/project"
 
 export async function generateDocs(targetDir: string) {
   // tslint:disable: no-console
@@ -49,6 +50,7 @@ export async function writeConfigReferenceDocs(docsRoot: string) {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           variables: {},
         },
       ],
diff --git a/garden-service/src/garden.ts b/garden-service/src/garden.ts
index 3314dba1b3..438c3382cd 100644
--- a/garden-service/src/garden.ts
+++ b/garden-service/src/garden.ts
@@ -122,7 +122,7 @@ export interface GardenParams {
   dotIgnoreFiles: string[]
   environmentName: string
   environmentConfigs: EnvironmentConfig[]
-  namespace?: string
+  namespace: string
   gardenDirPath: string
   log: LogEntry
   moduleIncludePatterns?: string[]
@@ -178,7 +178,7 @@ export class Garden {
   public readonly projectName: string
   public readonly environmentName: string
   public readonly environmentConfigs: EnvironmentConfig[]
-  public readonly namespace?: string
+  public readonly namespace: string
   public readonly variables: DeepPrimitiveMap
   public readonly secrets: StringMap
   public readonly projectSources: SourceConfig[]
@@ -1200,7 +1200,7 @@ export class DummyGarden extends Garden {
 export interface ConfigDump {
   environmentName: string // TODO: Remove this?
   allEnvironmentNames: string[]
-  namespace?: string
+  namespace: string
   providers: (Omit<Provider, "tools"> | ProviderConfig)[]
   variables: DeepPrimitiveMap
   moduleConfigs: ModuleConfig[]
diff --git a/garden-service/src/plugins/conftest/conftest.ts b/garden-service/src/plugins/conftest/conftest.ts
index 1d6dfed3e0..698cb75ce4 100644
--- a/garden-service/src/plugins/conftest/conftest.ts
+++ b/garden-service/src/plugins/conftest/conftest.ts
@@ -293,7 +293,9 @@ export const gardenPlugin = createGardenPlugin({
         {
           platform: "windows",
           architecture: "amd64",
-          url: "https://github.com/open-policy-agent/conftest/releases/download/v0.17.1/conftest_0.17.1_Windows_x86_64.zip",
+          url:
+            "https://github.com/open-policy-agent/conftest/releases/download/v0.17.1/" +
+            "conftest_0.17.1_Windows_x86_64.zip",
           sha256: "4c2df80420f2f148ec085bb75a8c5b92e1c665c6a041768a79924c81082527c3",
           extract: {
             format: "zip",
diff --git a/garden-service/src/plugins/container/config.ts b/garden-service/src/plugins/container/config.ts
index 497aed6a0d..c24705c669 100644
--- a/garden-service/src/plugins/container/config.ts
+++ b/garden-service/src/plugins/container/config.ts
@@ -557,7 +557,7 @@ export interface ContainerModuleSpec extends ModuleSpec {
 
 export interface ContainerModuleConfig extends ModuleConfig<ContainerModuleSpec> {}
 
-export const defaultNamespace = "_"
+export const defaultImageNamespace = "_"
 export const defaultTag = "latest"
 
 export const containerModuleSpecSchema = () =>
diff --git a/garden-service/src/plugins/container/helpers.ts b/garden-service/src/plugins/container/helpers.ts
index 4ffb1eebeb..ec171dafb0 100644
--- a/garden-service/src/plugins/container/helpers.ts
+++ b/garden-service/src/plugins/container/helpers.ts
@@ -14,7 +14,13 @@ import isGlob from "is-glob"
 import { ConfigurationError, RuntimeError } from "../../exceptions"
 import { splitFirst, spawn, splitLast, SpawnOutput } from "../../util/util"
 import { ModuleConfig } from "../../config/module"
-import { ContainerModule, ContainerRegistryConfig, defaultTag, defaultNamespace, ContainerModuleConfig } from "./config"
+import {
+  ContainerModule,
+  ContainerRegistryConfig,
+  defaultTag,
+  defaultImageNamespace,
+  ContainerModuleConfig,
+} from "./config"
 import { Writable } from "stream"
 import Bluebird from "bluebird"
 import { flatten, uniq, fromPairs } from "lodash"
@@ -200,7 +206,7 @@ const helpers = {
     const name = parsed.tag ? `${parsed.repository}:${parsed.tag}` : parsed.repository
 
     if (parsed.host) {
-      return `${parsed.host}/${parsed.namespace || defaultNamespace}/${name}`
+      return `${parsed.host}/${parsed.namespace || defaultImageNamespace}/${name}`
     } else if (parsed.namespace) {
       return `${parsed.namespace}/${name}`
     } else {
diff --git a/garden-service/src/plugins/kubernetes/config.ts b/garden-service/src/plugins/kubernetes/config.ts
index 6b542a38a0..994d3f69af 100644
--- a/garden-service/src/plugins/kubernetes/config.ts
+++ b/garden-service/src/plugins/kubernetes/config.ts
@@ -97,7 +97,6 @@ export interface KubernetesConfig extends ProviderConfig {
   }
   context: string
   defaultHostname?: string
-  defaultUsername?: string
   deploymentRegistry?: ContainerRegistryConfig
   deploymentStrategy?: DeploymentStrategy
   forceSsl: boolean
@@ -349,7 +348,6 @@ export const kubernetesConfigBase = providerConfigBaseSchema().keys({
     .string()
     .description("A default hostname to use when no hostname is explicitly configured for a service.")
     .example("api.mydomain.com"),
-  defaultUsername: joiIdentifier().description("Set a default username (used for namespacing within a cluster)."),
   deploymentStrategy: joi
     .string()
     .default("rolling")
@@ -571,9 +569,9 @@ export const configSchema = kubernetesConfigBase
       .posixPath()
       .description("Path to kubeconfig file to use instead of the system default. Must be a POSIX-style path."),
     namespace: joi.string().description(dedent`
-      Specify which namespace to deploy services to. Defaults to the environment namespace, if specified and enabled, otherwise the project name.
+      Specify which namespace to deploy services to. Defaults to \`<project name>-<environment namespace>\`.
 
-      Note that the framework generates other namespaces as well with this name as a prefix.
+      Note that the framework may generate other namespaces as well with this name as a prefix.
       `),
     setupIngressController: joi
       .string()
diff --git a/garden-service/src/plugins/kubernetes/kubectl.ts b/garden-service/src/plugins/kubernetes/kubectl.ts
index 324008be89..349d365ce4 100644
--- a/garden-service/src/plugins/kubernetes/kubectl.ts
+++ b/garden-service/src/plugins/kubernetes/kubectl.ts
@@ -136,23 +136,19 @@ class Kubectl extends PluginTool {
   }
 
   async stdout(params: KubectlParams) {
-    this.prepareArgs(params)
     return super.stdout(params)
   }
 
   async exec(params: KubectlParams) {
-    this.prepareArgs(params)
-    return super.exec(params)
+    return super.exec(this.prepareArgs(params))
   }
 
   async spawn(params: KubectlParams) {
-    this.prepareArgs(params)
-    return super.spawn(params)
+    return super.spawn(this.prepareArgs(params))
   }
 
   async spawnAndWait(params: KubectlSpawnParams) {
-    this.prepareArgs(params)
-    return super.spawnAndWait(params)
+    return super.spawnAndWait(this.prepareArgs(params))
   }
 
   async json(params: KubectlParams): Promise<any> {
@@ -168,7 +164,11 @@ class Kubectl extends PluginTool {
   private prepareArgs(params: KubectlParams) {
     const { namespace, configPath, args } = params
 
-    const opts: string[] = [`--context=${this.provider.config.context}`]
+    const opts: string[] = []
+
+    if (this.provider.config.context) {
+      opts.push(`--context=${this.provider.config.context}`)
+    }
 
     if (this.provider.config.kubeconfig) {
       opts.push(`--kubeconfig=${this.provider.config.kubeconfig}`)
@@ -182,7 +182,7 @@ class Kubectl extends PluginTool {
       opts.push(`--kubeconfig=${configPath}`)
     }
 
-    params.args = opts.concat(args)
+    return { ...params, args: opts.concat(args) }
   }
 }
 
diff --git a/garden-service/src/plugins/kubernetes/kubernetes.ts b/garden-service/src/plugins/kubernetes/kubernetes.ts
index 41bea78959..a9ab29e5e0 100644
--- a/garden-service/src/plugins/kubernetes/kubernetes.ts
+++ b/garden-service/src/plugins/kubernetes/kubernetes.ts
@@ -50,7 +50,7 @@ export async function configureProvider({
   config._systemServices = []
 
   if (!config.namespace) {
-    config.namespace = namespace || projectName
+    config.namespace = `${projectName}-${namespace}`
   }
 
   if (config.setupIngressController === "nginx") {
diff --git a/garden-service/src/plugins/kubernetes/run.ts b/garden-service/src/plugins/kubernetes/run.ts
index c9d27bdf60..1fdc75e476 100644
--- a/garden-service/src/plugins/kubernetes/run.ts
+++ b/garden-service/src/plugins/kubernetes/run.ts
@@ -157,7 +157,7 @@ export async function runAndCopy({
       podName: runner.podName,
       containerNames: [mainContainerName],
     })
-    return containerLogs[0].log
+    return containerLogs[0]?.log || ""
   }
 
   const timedOutResult = async () => {
diff --git a/garden-service/src/plugins/kubernetes/system.ts b/garden-service/src/plugins/kubernetes/system.ts
index 875871dd24..68d1a085db 100644
--- a/garden-service/src/plugins/kubernetes/system.ts
+++ b/garden-service/src/plugins/kubernetes/system.ts
@@ -27,6 +27,7 @@ import { KubernetesResource } from "./types"
 import { defaultDotIgnoreFiles } from "../../util/fs"
 import { LogLevel } from "../../logger/log-node"
 import { ConftestProviderConfig } from "../conftest/conftest"
+import { defaultNamespace } from "../../config/project"
 
 const GARDEN_VERSION = getPackageVersion()
 const SYSTEM_NAMESPACE_MIN_VERSION = "0.9.0"
@@ -79,7 +80,7 @@ export async function getSystemGarden(
       name: systemNamespace,
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [sysProvider, conftest],
       variables,
     },
diff --git a/garden-service/test/integ/src/plugins/conftest/conftest-container.ts b/garden-service/test/integ/src/plugins/conftest/conftest-container.ts
index 4ca087ccc0..aa2a764010 100644
--- a/garden-service/test/integ/src/plugins/conftest/conftest-container.ts
+++ b/garden-service/test/integ/src/plugins/conftest/conftest-container.ts
@@ -6,7 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-import { ProjectConfig } from "../../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../../../src/constants"
 import { Garden } from "../../../../../src/garden"
 import { getDataDir } from "../../../../helpers"
@@ -22,7 +22,7 @@ describe("conftest-container provider", () => {
     path: projectRoot,
     defaultEnvironment: "default",
     dotIgnoreFiles: [],
-    environments: [{ name: "default", variables: {} }],
+    environments: [{ name: "default", defaultNamespace, variables: {} }],
     providers: [{ name: "conftest-container", policyPath: "dockerfile.rego" }],
     variables: {},
   }
diff --git a/garden-service/test/integ/src/plugins/conftest/conftest.ts b/garden-service/test/integ/src/plugins/conftest/conftest.ts
index 529eb4e944..f3638a0069 100644
--- a/garden-service/test/integ/src/plugins/conftest/conftest.ts
+++ b/garden-service/test/integ/src/plugins/conftest/conftest.ts
@@ -6,7 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-import { ProjectConfig } from "../../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../../../src/constants"
 import { Garden } from "../../../../../src/garden"
 import { getDataDir } from "../../../../helpers"
@@ -24,7 +24,7 @@ describe("conftest provider", () => {
     path: projectRoot,
     defaultEnvironment: "default",
     dotIgnoreFiles: [],
-    environments: [{ name: "default", variables: {} }],
+    environments: [{ name: "default", defaultNamespace, variables: {} }],
     providers: [{ name: "conftest", policyPath: "policy.rego" }],
     variables: {},
   }
diff --git a/garden-service/test/integ/src/plugins/hadolint/hadolint.ts b/garden-service/test/integ/src/plugins/hadolint/hadolint.ts
index e66d7ed138..eac3ed2e77 100644
--- a/garden-service/test/integ/src/plugins/hadolint/hadolint.ts
+++ b/garden-service/test/integ/src/plugins/hadolint/hadolint.ts
@@ -7,7 +7,7 @@
  */
 
 import tmp from "tmp-promise"
-import { ProjectConfig } from "../../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../../src/config/project"
 import execa = require("execa")
 import { DEFAULT_API_VERSION } from "../../../../../src/constants"
 import { Garden } from "../../../../../src/garden"
@@ -39,7 +39,7 @@ describe("hadolint provider", () => {
       path: tmpPath,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "hadolint" }],
       variables: {},
     }
diff --git a/garden-service/test/integ/src/plugins/kubernetes/container/container.ts b/garden-service/test/integ/src/plugins/kubernetes/container/container.ts
index b523e841fd..2e617e7c3d 100644
--- a/garden-service/test/integ/src/plugins/kubernetes/container/container.ts
+++ b/garden-service/test/integ/src/plugins/kubernetes/container/container.ts
@@ -108,7 +108,7 @@ describe("kubernetes container module handlers", () => {
   before(async () => {
     garden = await makeTestGarden(root)
     provider = <KubernetesProvider>await garden.resolveProvider(garden.log, "local-kubernetes")
-    namespace = garden.projectName
+    namespace = provider.config.namespace!
   })
 
   beforeEach(async () => {
@@ -161,7 +161,7 @@ describe("kubernetes container module handlers", () => {
         args: [],
         interactive: false,
         module,
-        namespace: garden.projectName,
+        namespace: provider.config.namespace!,
         podName,
         runtimeContext: { envVars: {}, dependencies: [] },
         image,
diff --git a/garden-service/test/integ/src/plugins/kubernetes/container/deployment.ts b/garden-service/test/integ/src/plugins/kubernetes/container/deployment.ts
index 6b820f8dfc..c5934bb6d6 100644
--- a/garden-service/test/integ/src/plugins/kubernetes/container/deployment.ts
+++ b/garden-service/test/integ/src/plugins/kubernetes/container/deployment.ts
@@ -51,13 +51,14 @@ describe("kubernetes container deployment handlers", () => {
 
     it("should create a basic Deployment resource", async () => {
       const service = graph.getService("simple-service")
+      const namespace = provider.config.namespace!
 
       const resource = await createWorkloadManifest({
         api,
         provider,
         service,
         runtimeContext: emptyRuntimeContext,
-        namespace: garden.projectName,
+        namespace,
         enableHotReload: false,
         log: garden.log,
         production: false,
@@ -71,7 +72,7 @@ describe("kubernetes container deployment handlers", () => {
         metadata: {
           name: "simple-service-" + version,
           annotations: { "garden.io/configured.replicas": "1" },
-          namespace: "container",
+          namespace,
           labels: { "module": "simple-service", "service": "simple-service", "garden.io/version": version },
         },
         spec: {
@@ -131,7 +132,7 @@ describe("kubernetes container deployment handlers", () => {
       }
       await api.upsert({ kind: "Secret", namespace: "default", obj: authSecret, log: garden.log })
 
-      const namespace = garden.projectName
+      const namespace = provider.config.namespace!
       const _provider = cloneDeep(provider)
       _provider.config.imagePullSecrets = [{ name: secretName, namespace: "default" }]
 
@@ -169,7 +170,7 @@ describe("kubernetes container deployment handlers", () => {
       }
       await api.upsert({ kind: "Secret", namespace: "default", obj: authSecret, log: garden.log })
 
-      const namespace = garden.projectName
+      const namespace = provider.config.namespace!
       const _provider = cloneDeep(provider)
       _provider.config.imagePullSecrets = [{ name: secretName, namespace: "default" }]
 
@@ -191,7 +192,7 @@ describe("kubernetes container deployment handlers", () => {
 
     it("should correctly mount a referenced PVC module", async () => {
       const service = graph.getService("volume-reference")
-      const namespace = garden.projectName
+      const namespace = provider.config.namespace!
 
       const resource = await createWorkloadManifest({
         api,
@@ -212,7 +213,7 @@ describe("kubernetes container deployment handlers", () => {
 
     it("should throw if incompatible module is specified as a volume module", async () => {
       const service = graph.getService("volume-reference")
-      const namespace = garden.projectName
+      const namespace = provider.config.namespace!
 
       service.spec.volumes = [{ name: "test", module: "simple-service" }]
 
diff --git a/garden-service/test/integ/src/plugins/kubernetes/util.ts b/garden-service/test/integ/src/plugins/kubernetes/util.ts
index d5b43dcd31..8a1b82cfcb 100644
--- a/garden-service/test/integ/src/plugins/kubernetes/util.ts
+++ b/garden-service/test/integ/src/plugins/kubernetes/util.ts
@@ -96,7 +96,7 @@ describe("util", () => {
           provider,
           service,
           runtimeContext: emptyRuntimeContext,
-          namespace: "container",
+          namespace: provider.config.namespace!,
           enableHotReload: false,
           log: garden.log,
           production: false,
diff --git a/garden-service/test/integ/src/plugins/kubernetes/volume/persistentvolumeclaim.ts b/garden-service/test/integ/src/plugins/kubernetes/volume/persistentvolumeclaim.ts
index dd8c7f4fbe..072417d483 100644
--- a/garden-service/test/integ/src/plugins/kubernetes/volume/persistentvolumeclaim.ts
+++ b/garden-service/test/integ/src/plugins/kubernetes/volume/persistentvolumeclaim.ts
@@ -7,7 +7,7 @@
  */
 
 import tmp from "tmp-promise"
-import { ProjectConfig } from "../../../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../../../src/config/project"
 import execa = require("execa")
 import { DEFAULT_API_VERSION } from "../../../../../../src/constants"
 import { expect } from "chai"
@@ -32,7 +32,7 @@ describe("persistentvolumeclaim", () => {
       path: tmpDir.path,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "local-kubernetes", namespace: "default" }],
       variables: {},
     }
diff --git a/garden-service/test/unit/src/actions.ts b/garden-service/test/unit/src/actions.ts
index a61eb0f741..2a93121bca 100644
--- a/garden-service/test/unit/src/actions.ts
+++ b/garden-service/test/unit/src/actions.ts
@@ -29,7 +29,7 @@ import { expect } from "chai"
 import { omit } from "lodash"
 import { joi } from "../../../src/config/common"
 import { validateSchema } from "../../../src/config/validation"
-import { ProjectConfig } from "../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../src/constants"
 import { defaultProvider } from "../../../src/config/provider"
 import { RunTaskResult } from "../../../src/types/plugin/task/runTask"
@@ -56,7 +56,7 @@ describe("ActionRouter", () => {
     path: projectRootA,
     defaultEnvironment: "default",
     dotIgnoreFiles: defaultDotIgnoreFiles,
-    environments: [{ name: "default", variables: {} }],
+    environments: [{ name: "default", defaultNamespace, variables: {} }],
     providers: [{ name: "base" }, { name: "test-plugin" }, { name: "test-plugin-b" }],
     variables: {},
   }
@@ -887,7 +887,7 @@ describe("ActionRouter", () => {
             path,
             defaultEnvironment: "default",
             dotIgnoreFiles: [],
-            environments: [{ name: "default", variables: {} }],
+            environments: [{ name: "default", defaultNamespace, variables: {} }],
             providers: [{ name: "foo" }],
             variables: {},
           },
@@ -940,7 +940,7 @@ describe("ActionRouter", () => {
             path,
             defaultEnvironment: "default",
             dotIgnoreFiles: [],
-            environments: [{ name: "default", variables: {} }],
+            environments: [{ name: "default", defaultNamespace, variables: {} }],
             providers: [{ name: "base" }, { name: "foo" }],
             variables: {},
           },
@@ -1005,7 +1005,7 @@ describe("ActionRouter", () => {
             path,
             defaultEnvironment: "default",
             dotIgnoreFiles: [],
-            environments: [{ name: "default", variables: {} }],
+            environments: [{ name: "default", defaultNamespace, variables: {} }],
             providers: [
               { name: "base" },
               // The order here matters, to verify that the dependency ordering works
@@ -1074,7 +1074,7 @@ describe("ActionRouter", () => {
               path,
               defaultEnvironment: "default",
               dotIgnoreFiles: [],
-              environments: [{ name: "default", variables: {} }],
+              environments: [{ name: "default", defaultNamespace, variables: {} }],
               providers: [
                 { name: "base" },
                 // The order here matters, since we use that as a "tie-breaker"
@@ -1131,7 +1131,7 @@ describe("ActionRouter", () => {
             path,
             defaultEnvironment: "default",
             dotIgnoreFiles: [],
-            environments: [{ name: "default", variables: {} }],
+            environments: [{ name: "default", defaultNamespace, variables: {} }],
             providers: [{ name: "base" }, { name: "foo" }],
             variables: {},
           },
@@ -1155,7 +1155,7 @@ describe("ActionRouter", () => {
         path,
         defaultEnvironment: "default",
         dotIgnoreFiles: [],
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "base" }, { name: "foo" }],
         variables: {},
       }
@@ -1297,7 +1297,7 @@ describe("ActionRouter", () => {
             path,
             defaultEnvironment: "default",
             dotIgnoreFiles: [],
-            environments: [{ name: "default", variables: {} }],
+            environments: [{ name: "default", defaultNamespace, variables: {} }],
             providers: [{ name: "base-a" }, { name: "base-b" }, { name: "foo" }],
             variables: {},
           },
@@ -1389,7 +1389,7 @@ describe("ActionRouter", () => {
           path,
           defaultEnvironment: "default",
           dotIgnoreFiles: [],
-          environments: [{ name: "default", variables: {} }],
+          environments: [{ name: "default", defaultNamespace, variables: {} }],
           providers: [{ name: "foo" }],
           variables: {},
         },
diff --git a/garden-service/test/unit/src/commands/get/get-outputs.ts b/garden-service/test/unit/src/commands/get/get-outputs.ts
index a4bb7f048a..dff57c73dd 100644
--- a/garden-service/test/unit/src/commands/get/get-outputs.ts
+++ b/garden-service/test/unit/src/commands/get/get-outputs.ts
@@ -10,7 +10,7 @@ import { expect } from "chai"
 import tmp from "tmp-promise"
 import { withDefaultGlobalOpts, TestGarden } from "../../../../helpers"
 import { GetOutputsCommand } from "../../../../../src/commands/get/get-outputs"
-import { ProjectConfig } from "../../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../../../src/constants"
 import { createGardenPlugin } from "../../../../../src/types/plugin/plugin"
 import { exec } from "../../../../../src/util/util"
@@ -31,7 +31,7 @@ describe("GetOutputsCommand", () => {
       path: tmpDir.path,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "test" }],
       variables: {},
     }
diff --git a/garden-service/test/unit/src/commands/get/get-status.ts b/garden-service/test/unit/src/commands/get/get-status.ts
index fbaf2f05d5..ffe3a54955 100644
--- a/garden-service/test/unit/src/commands/get/get-status.ts
+++ b/garden-service/test/unit/src/commands/get/get-status.ts
@@ -9,7 +9,7 @@
 import tmp from "tmp-promise"
 import execa from "execa"
 
-import { ProjectConfig } from "../../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../../../src/constants"
 import { createGardenPlugin } from "../../../../../src/types/plugin/plugin"
 import { joi } from "../../../../../src/config/common"
@@ -37,7 +37,7 @@ describe("GetStatusCommand", () => {
       path: tmpDir.path,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "test" }],
       variables: {},
     }
diff --git a/garden-service/test/unit/src/commands/run/workflow.ts b/garden-service/test/unit/src/commands/run/workflow.ts
index 5971d304db..36f375f867 100644
--- a/garden-service/test/unit/src/commands/run/workflow.ts
+++ b/garden-service/test/unit/src/commands/run/workflow.ts
@@ -15,7 +15,7 @@ import { RunWorkflowCommand } from "../../../../../src/commands/run/workflow"
 import { createGardenPlugin } from "../../../../../src/types/plugin/plugin"
 import { joi } from "../../../../../src/config/common"
 import { RunTaskParams } from "../../../../../src/types/plugin/task/runTask"
-import { ProjectConfig } from "../../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../../src/config/project"
 import { join } from "path"
 import { remove, readFile, pathExists } from "fs-extra"
 import { defaultDotIgnoreFiles } from "../../../../../src/util/fs"
@@ -249,7 +249,7 @@ describe("RunWorkflowCommand", () => {
       path: tmpDir.path,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "test" }],
       variables: {},
     }
@@ -338,7 +338,7 @@ describe("RunWorkflowCommand", () => {
       path: garden.projectRoot,
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "test" }],
       variables: {},
     }
diff --git a/garden-service/test/unit/src/commands/tools.ts b/garden-service/test/unit/src/commands/tools.ts
index 769a2e61fe..de5c0e5d58 100644
--- a/garden-service/test/unit/src/commands/tools.ts
+++ b/garden-service/test/unit/src/commands/tools.ts
@@ -26,6 +26,7 @@ import { LogLevel } from "../../../../src/logger/log-node"
 import { dedent } from "../../../../src/util/string"
 import { LogEntry } from "../../../../src/logger/log-entry"
 import { makeDummyGarden } from "../../../../src/cli/cli"
+import { defaultNamespace } from "../../../../src/config/project"
 
 describe("ToolsCommand", () => {
   let tmpDir: TempDirectory
@@ -100,7 +101,7 @@ describe("ToolsCommand", () => {
         path: tmpDir.path,
         defaultEnvironment: "default",
         dotIgnoreFiles: [],
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test-a" }],
         variables: {},
       },
diff --git a/garden-service/test/unit/src/commands/util.ts b/garden-service/test/unit/src/commands/util.ts
index 3a60ab3305..5bdb14f20f 100644
--- a/garden-service/test/unit/src/commands/util.ts
+++ b/garden-service/test/unit/src/commands/util.ts
@@ -14,6 +14,7 @@ import { DEFAULT_API_VERSION, GARDEN_GLOBAL_PATH } from "../../../../src/constan
 import { createGardenPlugin } from "../../../../src/types/plugin/plugin"
 import { pick } from "lodash"
 import { join } from "path"
+import { defaultNamespace } from "../../../../src/config/project"
 
 describe("FetchToolsCommand", () => {
   let tmpDir: TempDirectory
@@ -55,7 +56,7 @@ describe("FetchToolsCommand", () => {
         path: tmpDir.path,
         defaultEnvironment: "default",
         dotIgnoreFiles: [],
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test" }],
         variables: {},
       },
@@ -98,7 +99,7 @@ describe("FetchToolsCommand", () => {
         path: tmpDir.path,
         defaultEnvironment: "default",
         dotIgnoreFiles: [],
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [],
         variables: {},
       },
diff --git a/garden-service/test/unit/src/config/project.ts b/garden-service/test/unit/src/config/project.ts
index 7f0a527eca..0871308c69 100644
--- a/garden-service/test/unit/src/config/project.ts
+++ b/garden-service/test/unit/src/config/project.ts
@@ -17,6 +17,7 @@ import {
   defaultVarfilePath,
   defaultEnvVarfilePath,
   parseEnvironment,
+  defaultNamespace,
 } from "../../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../../src/constants"
 import { expectError } from "../../../helpers"
@@ -24,6 +25,7 @@ import { defaultDotIgnoreFiles } from "../../../../src/util/fs"
 import { realpath, writeFile } from "fs-extra"
 import { dedent } from "../../../../src/util/string"
 import { resolve } from "path"
+import stripAnsi from "strip-ansi"
 
 describe("resolveProjectConfig", () => {
   it("should pass through a canonical project config", async () => {
@@ -34,7 +36,7 @@ describe("resolveProjectConfig", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       outputs: [],
       providers: [{ name: "some-provider" }],
       variables: {},
@@ -45,7 +47,7 @@ describe("resolveProjectConfig", () => {
       environments: [
         {
           name: "default",
-          namespacing: "optional",
+          defaultNamespace,
           production: false,
           providers: [],
           variables: {},
@@ -91,6 +93,7 @@ describe("resolveProjectConfig", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           variables: {
             envVar: "${local.env.TEST_ENV_VAR}",
           },
@@ -115,7 +118,7 @@ describe("resolveProjectConfig", () => {
       environments: [
         {
           name: "default",
-          namespacing: "optional",
+          defaultNamespace,
           production: false,
           providers: [],
           variables: {
@@ -150,6 +153,7 @@ describe("resolveProjectConfig", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           variables: {
             envVar: "foo",
           },
@@ -177,7 +181,7 @@ describe("resolveProjectConfig", () => {
       environments: [
         {
           name: "default",
-          namespacing: "optional",
+          defaultNamespace,
           production: false,
           providers: [],
           variables: {
@@ -262,6 +266,7 @@ describe("resolveProjectConfig", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           variables: {
             envVar: "foo",
           },
@@ -288,7 +293,7 @@ describe("resolveProjectConfig", () => {
       environments: [
         {
           name: "default",
-          namespacing: "optional",
+          defaultNamespace,
           production: false,
           providers: [],
           variables: {
@@ -325,6 +330,7 @@ describe("resolveProjectConfig", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           providers: [
             {
               name: "provider-b",
@@ -351,7 +357,7 @@ describe("resolveProjectConfig", () => {
       environments: [
         {
           name: "default",
-          namespacing: "optional",
+          defaultNamespace,
           providers: [],
           production: false,
           variables: {
@@ -399,7 +405,7 @@ describe("pickEnvironment", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [],
       variables: {},
     }
@@ -415,14 +421,14 @@ describe("pickEnvironment", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [],
       variables: {},
     }
 
     expect(await pickEnvironment(config, "default")).to.eql({
       environmentName: "default",
-      namespace: undefined,
+      namespace: "default",
       providers: [{ name: "exec" }, { name: "container" }],
       production: false,
       variables: {},
@@ -437,7 +443,7 @@ describe("pickEnvironment", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [
         { name: "container", newKey: "foo" },
         { name: "my-provider", a: "a" },
@@ -449,7 +455,7 @@ describe("pickEnvironment", () => {
 
     expect(await pickEnvironment(config, "default")).to.eql({
       environmentName: "default",
-      namespace: undefined,
+      namespace: "default",
       providers: [{ name: "exec" }, { name: "container", newKey: "foo" }, { name: "my-provider", a: "c", b: "b" }],
       production: false,
       variables: {},
@@ -464,7 +470,7 @@ describe("pickEnvironment", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [
         { name: "container", newKey: "foo" },
         { name: "my-provider", a: "a" },
@@ -476,7 +482,7 @@ describe("pickEnvironment", () => {
 
     expect(await pickEnvironment(config, "default")).to.eql({
       environmentName: "default",
-      namespace: undefined,
+      namespace: "default",
       providers: [{ name: "exec" }, { name: "container", newKey: "foo" }, { name: "my-provider", b: "b" }],
       production: false,
       variables: {},
@@ -494,6 +500,7 @@ describe("pickEnvironment", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           variables: {
             b: "env value B",
             c: "env value C",
@@ -552,6 +559,7 @@ describe("pickEnvironment", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           variables: {
             b: "B",
             c: "c",
@@ -591,6 +599,7 @@ describe("pickEnvironment", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           variables: {},
         },
       ],
@@ -630,6 +639,7 @@ describe("pickEnvironment", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           variables: {
             b: "B",
             c: "c",
@@ -670,6 +680,7 @@ describe("pickEnvironment", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           varfile: "foo.env",
           variables: {},
         },
@@ -719,6 +730,7 @@ describe("pickEnvironment", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           // Precedence 2/4
           variables: {
             c: "C",
@@ -756,6 +768,7 @@ describe("pickEnvironment", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           variables: {},
         },
       ],
@@ -781,6 +794,7 @@ describe("pickEnvironment", () => {
       environments: [
         {
           name: "default",
+          defaultNamespace,
           varfile: "foo.env",
           variables: {},
         },
@@ -795,7 +809,7 @@ describe("pickEnvironment", () => {
     )
   })
 
-  it("should set environment namespace if specified", async () => {
+  it("should set environment namespace if specified and defaultNamespace=null", async () => {
     const config: ProjectConfig = {
       apiVersion: DEFAULT_API_VERSION,
       kind: "Project",
@@ -803,7 +817,7 @@ describe("pickEnvironment", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [],
       variables: {},
     }
@@ -817,7 +831,7 @@ describe("pickEnvironment", () => {
     })
   })
 
-  it("should set defaultNamespace if set and no explicit namespace is specified", async () => {
+  it("should use explicit namespace if specified and there is a default", async () => {
     const config: ProjectConfig = {
       apiVersion: DEFAULT_API_VERSION,
       kind: "Project",
@@ -825,21 +839,21 @@ describe("pickEnvironment", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", defaultNamespace: "default-ns", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [],
       variables: {},
     }
 
-    expect(await pickEnvironment(config, "default")).to.eql({
+    expect(await pickEnvironment(config, "foo.default")).to.eql({
       environmentName: "default",
-      namespace: "default-ns",
+      namespace: "foo",
       providers: [{ name: "exec" }, { name: "container" }],
       production: false,
       variables: {},
     })
   })
 
-  it("should use explicit namespace if specified, if defaultNamespace is set", async () => {
+  it("should use defaultNamespace if set and no explicit namespace is specified", async () => {
     const config: ProjectConfig = {
       apiVersion: DEFAULT_API_VERSION,
       kind: "Project",
@@ -847,14 +861,14 @@ describe("pickEnvironment", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", defaultNamespace: "default-ns", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [],
       variables: {},
     }
 
-    expect(await pickEnvironment(config, "foo.default")).to.eql({
+    expect(await pickEnvironment(config, "default")).to.eql({
       environmentName: "default",
-      namespace: "foo",
+      namespace: "default",
       providers: [{ name: "exec" }, { name: "container" }],
       production: false,
       variables: {},
@@ -869,7 +883,7 @@ describe("pickEnvironment", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [],
       variables: {},
     }
@@ -883,7 +897,7 @@ describe("pickEnvironment", () => {
     )
   })
 
-  it("should throw if environment requires namespace but none is specified and no defaultNamespace set", async () => {
+  it("should throw if environment requires namespace but none is specified and defaultNamespace=null", async () => {
     const config: ProjectConfig = {
       apiVersion: DEFAULT_API_VERSION,
       kind: "Project",
@@ -891,7 +905,7 @@ describe("pickEnvironment", () => {
       path: "/tmp/foo",
       defaultEnvironment: "default",
       dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", namespacing: "required", variables: {} }],
+      environments: [{ name: "default", defaultNamespace: null, variables: {} }],
       providers: [],
       variables: {},
     }
@@ -899,30 +913,8 @@ describe("pickEnvironment", () => {
     await expectError(
       () => pickEnvironment(config, "default"),
       (err) =>
-        expect(err.message).to.equal(
-          "Environment default requires a namespace, but none was specified and no defaultNamespace is configured."
-        )
-    )
-  })
-
-  it("should throw if environment doesn't allow namespacing but one is specified", async () => {
-    const config: ProjectConfig = {
-      apiVersion: DEFAULT_API_VERSION,
-      kind: "Project",
-      name: "my-project",
-      path: "/tmp/foo",
-      defaultEnvironment: "default",
-      dotIgnoreFiles: defaultDotIgnoreFiles,
-      environments: [{ name: "default", namespacing: "disabled", variables: {} }],
-      providers: [],
-      variables: {},
-    }
-
-    await expectError(
-      () => pickEnvironment(config, "foo.default"),
-      (err) =>
-        expect(err.message).to.equal(
-          "Environment default does not allow namespacing, but namespace 'foo' was specified."
+        expect(stripAnsi(err.message)).to.equal(
+          "Environment default has defaultNamespace set to null, and no explicit namespace was specified. Please either set a defaultNamespace or explicitly set a namespace at runtime (e.g. --env=some-namespace.default)."
         )
     )
   })
diff --git a/garden-service/test/unit/src/config/workflow.ts b/garden-service/test/unit/src/config/workflow.ts
index a6228d6d66..0a35d809fc 100644
--- a/garden-service/test/unit/src/config/workflow.ts
+++ b/garden-service/test/unit/src/config/workflow.ts
@@ -16,7 +16,8 @@ import {
   TriggerSpec,
 } from "../../../../src/config/workflow"
 import { defaultContainerLimits } from "../../../../src/plugins/container/config"
-import { EnvironmentConfig } from "../../../../src/config/project"
+import { EnvironmentConfig, defaultNamespace } from "../../../../src/config/project"
+import stripAnsi from "strip-ansi"
 
 describe("resolveWorkflowConfig", () => {
   let garden: TestGarden
@@ -44,7 +45,7 @@ describe("resolveWorkflowConfig", () => {
       triggers: [
         {
           environment: "local",
-          namespace: undefined,
+          namespace: "default",
           events: ["pull-request"],
           branches: ["feature*"],
           ignoreBranches: ["feature-ignored*"],
@@ -169,7 +170,7 @@ describe("resolveWorkflowConfig", () => {
       const environmentConfigs: EnvironmentConfig[] = [
         {
           name: "test",
-          namespacing: "optional",
+          defaultNamespace,
           variables: {},
         },
       ]
@@ -182,7 +183,7 @@ describe("resolveWorkflowConfig", () => {
       const environmentConfigs: EnvironmentConfig[] = [
         {
           name: "test",
-          namespacing: "required",
+          defaultNamespace: null,
           variables: {},
         },
       ]
@@ -190,28 +191,8 @@ describe("resolveWorkflowConfig", () => {
       expectError(
         () => populateNamespaceForTriggers({ ...config, triggers: [trigger] }, environmentConfigs),
         (err) =>
-          expect(err.message).to.match(
-            /Invalid namespace in trigger for workflow workflow-a: Environment test requires a namespace/
-          )
-      )
-    })
-
-    it("should throw if a trigger's environment does not allow namespaces, but one is specified", () => {
-      const environmentConfigs: EnvironmentConfig[] = [
-        {
-          name: "test",
-          namespacing: "disabled",
-          variables: {},
-        },
-      ]
-
-      const invalidTrigger = { ...trigger, namespace: "foo" }
-
-      expectError(
-        () => populateNamespaceForTriggers({ ...config, triggers: [invalidTrigger] }, environmentConfigs),
-        (err) =>
-          expect(err.message).to.match(
-            /Invalid namespace in trigger for workflow workflow-a: Environment test does not allow namespacing/
+          expect(stripAnsi(err.message)).to.equal(
+            `Invalid namespace in trigger for workflow workflow-a: Environment test has defaultNamespace set to null, and no explicit namespace was specified. Please either set a defaultNamespace or explicitly set a namespace at runtime (e.g. --env=some-namespace.test).`
           )
       )
     })
@@ -220,7 +201,6 @@ describe("resolveWorkflowConfig", () => {
       const environmentConfigs: EnvironmentConfig[] = [
         {
           name: "test",
-          namespacing: "optional",
           defaultNamespace: "foo",
           variables: {},
         },
@@ -235,7 +215,6 @@ describe("resolveWorkflowConfig", () => {
       const environmentConfigs: EnvironmentConfig[] = [
         {
           name: "test",
-          namespacing: "optional",
           defaultNamespace: "foo",
           variables: {},
         },
diff --git a/garden-service/test/unit/src/garden.ts b/garden-service/test/unit/src/garden.ts
index 32071b56a8..972383282a 100644
--- a/garden-service/test/unit/src/garden.ts
+++ b/garden-service/test/unit/src/garden.ts
@@ -33,7 +33,7 @@ import { ModuleVersion } from "../../../src/vcs/vcs"
 import { getModuleCacheContext } from "../../../src/types/module"
 import { createGardenPlugin } from "../../../src/types/plugin/plugin"
 import { ConfigureProviderParams } from "../../../src/types/plugin/provider/configureProvider"
-import { ProjectConfig } from "../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../src/config/project"
 import { ModuleConfig, baseModuleSpecSchema, baseBuildSpecSchema } from "../../../src/config/module"
 import { DEFAULT_API_VERSION } from "../../../src/constants"
 import { providerConfigBaseSchema } from "../../../src/config/provider"
@@ -64,7 +64,7 @@ describe("Garden", () => {
       path: pathFoo,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "foo" }],
       variables: {},
     }
@@ -275,7 +275,7 @@ describe("Garden", () => {
         path: pathFoo,
         defaultEnvironment: "default",
         dotIgnoreFiles: [],
-        environments: [{ name: "default", namespacing: "required", defaultNamespace: "foo", variables: {} }],
+        environments: [{ name: "default", defaultNamespace: "foo", variables: {} }],
         providers: [{ name: "foo" }],
         variables: {},
       }
@@ -286,28 +286,6 @@ describe("Garden", () => {
       expect(garden.namespace).to.equal("foo")
     })
 
-    it("should throw if a namespace is specified and the specified environment disables namespacing", async () => {
-      const config: ProjectConfig = {
-        apiVersion: DEFAULT_API_VERSION,
-        kind: "Project",
-        name: "test",
-        path: pathFoo,
-        defaultEnvironment: "default",
-        dotIgnoreFiles: [],
-        environments: [{ name: "default", namespacing: "disabled", variables: {} }],
-        providers: [{ name: "foo" }],
-        variables: {},
-      }
-
-      await expectError(
-        () => TestGarden.factory(pathFoo, { config, environmentName: "foo.default" }),
-        (err) =>
-          expect(err.message).to.equal(
-            "Environment default does not allow namespacing, but namespace 'foo' was specified."
-          )
-      )
-    })
-
     it("should throw if a namespace is not specified and the specified environment requires namespacing", async () => {
       const config: ProjectConfig = {
         apiVersion: DEFAULT_API_VERSION,
@@ -316,7 +294,7 @@ describe("Garden", () => {
         path: pathFoo,
         defaultEnvironment: "default",
         dotIgnoreFiles: [],
-        environments: [{ name: "default", namespacing: "required", variables: {} }],
+        environments: [{ name: "default", defaultNamespace: null, variables: {} }],
         providers: [{ name: "foo" }],
         variables: {},
       }
@@ -324,8 +302,8 @@ describe("Garden", () => {
       await expectError(
         () => TestGarden.factory(pathFoo, { config, environmentName: "default" }),
         (err) =>
-          expect(err.message).to.equal(
-            "Environment default requires a namespace, but none was specified and no defaultNamespace is configured."
+          expect(stripAnsi(err.message)).to.equal(
+            `Environment default has defaultNamespace set to null, and no explicit namespace was specified. Please either set a defaultNamespace or explicitly set a namespace at runtime (e.g. --env=some-namespace.default).`
           )
       )
     })
@@ -1425,7 +1403,7 @@ describe("Garden", () => {
         path: process.cwd(),
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test", foo: "bar" }],
         variables: {},
       }
@@ -1470,7 +1448,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test", foo: "${bla.ble}" }],
         variables: {},
       }
@@ -1499,7 +1477,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test", foo: "${providers.foo.config.bla}" }],
         variables: {},
       }
@@ -1520,7 +1498,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test", foo: "${secrets.missing}" }], // < ------
         variables: {},
       }
@@ -1572,7 +1550,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test", foo: "bar" }],
         variables: {},
       }
@@ -1601,7 +1579,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test-a" }, { name: "test-b" }],
         variables: {},
       }
@@ -1631,7 +1609,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test-a" }],
         variables: {},
       }
@@ -1660,7 +1638,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [
           { name: "test-a", foo: "${providers.test-b.outputs.foo}" },
           { name: "test-b", foo: "${providers.test-a.outputs.foo}" },
@@ -1697,7 +1675,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test-a", foo: "${providers.test-b.outputs.foo}" }, { name: "test-b" }],
         variables: {},
       }
@@ -1730,7 +1708,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test" }],
         variables: {},
       }
@@ -1757,7 +1735,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test", foo: 123 }],
         variables: {},
       }
@@ -1795,7 +1773,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test" }],
         variables: {},
       }
@@ -1837,7 +1815,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test-a" }, { name: "test-b", foo: "${providers.test-a.outputs.foo}" }],
         variables: {},
       }
@@ -1875,8 +1853,8 @@ describe("Garden", () => {
         defaultEnvironment: "dev",
         dotIgnoreFiles: defaultDotIgnoreFiles,
         environments: [
-          { name: "dev", variables: {} },
-          { name: "prod", variables: {} },
+          { name: "dev", defaultNamespace, variables: {} },
+          { name: "prod", defaultNamespace, variables: {} },
         ],
         providers: [
           { name: "test-a", environments: ["prod"] },
@@ -1905,7 +1883,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: { "my-variable": "bar" } }],
+        environments: [{ name: "default", defaultNamespace, variables: { "my-variable": "bar" } }],
         providers: [{ name: "test-a", foo: "${var.my-variable}" }],
         variables: {},
       }
@@ -1948,7 +1926,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test-a" }, { name: "test-b" }],
         variables: {},
       }
@@ -1998,7 +1976,7 @@ describe("Garden", () => {
         path: projectRootA,
         defaultEnvironment: "default",
         dotIgnoreFiles: defaultDotIgnoreFiles,
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test-a" }, { name: "test-b" }, { name: "test-c" }],
         variables: {},
       }
@@ -2034,7 +2012,7 @@ describe("Garden", () => {
           path: projectRootA,
           defaultEnvironment: "default",
           dotIgnoreFiles: defaultDotIgnoreFiles,
-          environments: [{ name: "default", variables: {} }],
+          environments: [{ name: "default", defaultNamespace, variables: {} }],
           providers: [{ name: "test", foo: 123 }],
           variables: {},
         }
@@ -2078,7 +2056,7 @@ describe("Garden", () => {
           path: projectRootA,
           defaultEnvironment: "default",
           dotIgnoreFiles: defaultDotIgnoreFiles,
-          environments: [{ name: "default", variables: {} }],
+          environments: [{ name: "default", defaultNamespace, variables: {} }],
           providers: [{ name: "test" }],
           variables: {},
         }
@@ -2326,7 +2304,7 @@ describe("Garden", () => {
           path: pathFoo,
           defaultEnvironment: "default",
           dotIgnoreFiles: [],
-          environments: [{ name: "default", variables: { some: { nested: { key: "my value" } } } }],
+          environments: [{ name: "default", defaultNamespace, variables: { some: { nested: { key: "my value" } } } }],
           providers: [{ name: "test" }],
           variables: {},
         },
@@ -2376,7 +2354,7 @@ describe("Garden", () => {
           path: pathFoo,
           defaultEnvironment: "default",
           dotIgnoreFiles: [],
-          environments: [{ name: "default", variables: { some: { nested: { key: "my value" } } } }],
+          environments: [{ name: "default", defaultNamespace, variables: { some: { nested: { key: "my value" } } } }],
           providers: [{ name: "test" }],
           variables: {},
         },
diff --git a/garden-service/test/unit/src/outputs.ts b/garden-service/test/unit/src/outputs.ts
index 0e485b4510..800c1dbad8 100644
--- a/garden-service/test/unit/src/outputs.ts
+++ b/garden-service/test/unit/src/outputs.ts
@@ -12,7 +12,7 @@ import { resolveProjectOutputs } from "../../../src/outputs"
 import { expect } from "chai"
 import { realpath } from "fs-extra"
 import { createGardenPlugin } from "../../../src/types/plugin/plugin"
-import { ProjectConfig } from "../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../src/constants"
 import { exec } from "../../../src/util/util"
 import { ServiceState } from "../../../src/types/service"
@@ -34,7 +34,7 @@ describe("resolveProjectOutputs", () => {
       path: tmpPath,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "test" }],
       variables: {},
     }
diff --git a/garden-service/test/unit/src/tasks/deploy.ts b/garden-service/test/unit/src/tasks/deploy.ts
index ec638bd45d..5c4fd73555 100644
--- a/garden-service/test/unit/src/tasks/deploy.ts
+++ b/garden-service/test/unit/src/tasks/deploy.ts
@@ -9,7 +9,7 @@
 import tmp from "tmp-promise"
 import execa from "execa"
 
-import { ProjectConfig } from "../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../../src/constants"
 import { Garden } from "../../../../src/garden"
 import { ConfigGraph } from "../../../../src/config-graph"
@@ -40,7 +40,7 @@ describe("DeployTask", () => {
       path: tmpDir.path,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "test" }],
       variables: {},
     }
diff --git a/garden-service/test/unit/src/tasks/get-service-status.ts b/garden-service/test/unit/src/tasks/get-service-status.ts
index 3f03a886c4..43dfa5834b 100644
--- a/garden-service/test/unit/src/tasks/get-service-status.ts
+++ b/garden-service/test/unit/src/tasks/get-service-status.ts
@@ -9,7 +9,7 @@
 import tmp from "tmp-promise"
 import execa from "execa"
 
-import { ProjectConfig } from "../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../../src/constants"
 import { createGardenPlugin } from "../../../../src/types/plugin/plugin"
 import { joi } from "../../../../src/config/common"
@@ -36,7 +36,7 @@ describe("GetServiceStatusTask", () => {
       path: tmpDir.path,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "test" }],
       variables: {},
     }
diff --git a/garden-service/test/unit/src/tasks/resolve-provider.ts b/garden-service/test/unit/src/tasks/resolve-provider.ts
index 7eeaccb624..1e5dbd362e 100644
--- a/garden-service/test/unit/src/tasks/resolve-provider.ts
+++ b/garden-service/test/unit/src/tasks/resolve-provider.ts
@@ -18,6 +18,7 @@ import { pathExists, writeFile, remove } from "fs-extra"
 import { join } from "path"
 import { serialize } from "v8"
 import moment from "moment"
+import { defaultNamespace } from "../../../../src/config/project"
 
 describe("ResolveProviderTask", () => {
   let tmpDir: TempDirectory
@@ -46,7 +47,7 @@ describe("ResolveProviderTask", () => {
         path: tmpDir.path,
         defaultEnvironment: "default",
         dotIgnoreFiles: [],
-        environments: [{ name: "default", variables: {} }],
+        environments: [{ name: "default", defaultNamespace, variables: {} }],
         providers: [{ name: "test-plugin" }],
         variables: {},
       },
diff --git a/garden-service/test/unit/src/tasks/task.ts b/garden-service/test/unit/src/tasks/task.ts
index b3e15d78ed..d33ca4175b 100644
--- a/garden-service/test/unit/src/tasks/task.ts
+++ b/garden-service/test/unit/src/tasks/task.ts
@@ -9,7 +9,7 @@
 import tmp from "tmp-promise"
 import { expect } from "chai"
 import { TestGarden } from "../../../helpers"
-import { ProjectConfig } from "../../../../src/config/project"
+import { ProjectConfig, defaultNamespace } from "../../../../src/config/project"
 import { DEFAULT_API_VERSION } from "../../../../src/constants"
 import execa from "execa"
 import { createGardenPlugin } from "../../../../src/types/plugin/plugin"
@@ -35,7 +35,7 @@ describe("TaskTask", () => {
       path: tmpDir.path,
       defaultEnvironment: "default",
       dotIgnoreFiles: [],
-      environments: [{ name: "default", variables: {} }],
+      environments: [{ name: "default", defaultNamespace, variables: {} }],
       providers: [{ name: "test" }],
       variables: {},
     }