diff --git a/apio/commands/build.py b/apio/commands/build.py
index d0a482ff..6a2d36bb 100644
--- a/apio/commands/build.py
+++ b/apio/commands/build.py
@@ -1,4 +1,4 @@
-"""DOC: TODO"""
+"""Main implementation of APIO BUILD command"""
 
 # -*- coding: utf-8 -*-
 # -- This file is part of the Apio project
@@ -6,6 +6,8 @@
 # -- Author Jesús Arroyo
 # -- Licence GPLv2
 
+from pathlib import Path
+
 import click
 
 from apio.managers.scons import SCons
@@ -34,8 +36,8 @@
 @click.option(
     "-p",
     "--project-dir",
-    type=str,
-    metavar="path",
+    type=Path,
+    metavar="project_dir",
     help="Set the target directory for the project.",
 )
 @click.option(
diff --git a/apio/commands/clean.py b/apio/commands/clean.py
index b001d5cd..5ef3e578 100644
--- a/apio/commands/clean.py
+++ b/apio/commands/clean.py
@@ -1,9 +1,12 @@
+"""Main implementation of APIO CLEAN command"""
+
 # -*- coding: utf-8 -*-
 # -- This file is part of the Apio project
 # -- (C) 2016-2019 FPGAwars
 # -- Author Jesús Arroyo
 # -- Licence GPLv2
-"""TODO"""
+
+from pathlib import Path
 
 import click
 
@@ -16,8 +19,8 @@
 @click.option(
     "-p",
     "--project-dir",
-    type=str,
-    metavar="path",
+    type=Path,
+    metavar="project_dir",
     help="Set the target directory for the project.",
 )
 @click.option(
@@ -31,7 +34,12 @@
 )
 def cli(ctx, board, project_dir, verbose):
     """Clean the previous generated files."""
-    exit_code = SCons(project_dir).clean(
-        {"board": board, "verbose": {"all": verbose}}
-    )
+
+    # -- Create the scons object
+    scons = SCons(project_dir)
+
+    # -- Build the project with the given parameters
+    exit_code = scons.clean({"board": board, "verbose": {"all": verbose}})
+
+    # -- Done!
     ctx.exit(exit_code)
diff --git a/apio/commands/examples.py b/apio/commands/examples.py
index 7b53151f..7fdc2a61 100644
--- a/apio/commands/examples.py
+++ b/apio/commands/examples.py
@@ -5,6 +5,8 @@
 # -- Licence GPLv2
 """TODO"""
 
+from pathlib import Path
+
 import click
 
 from apio.managers.examples import Examples
@@ -36,9 +38,9 @@
 @click.option(
     "-p",
     "--project-dir",
-    type=str,
-    metavar="path",
-    help="Set the target directory for the examples.",
+    type=Path,
+    metavar="project_dir",
+    help="Set the target directory for the project.",
 )
 @click.option(
     "-n",
diff --git a/apio/commands/init.py b/apio/commands/init.py
index dbaf3777..7c79e32d 100644
--- a/apio/commands/init.py
+++ b/apio/commands/init.py
@@ -3,7 +3,9 @@
 # -- (C) 2016-2019 FPGAwars
 # -- Author Jesús Arroyo
 # -- Licence GPLv2
-"""TODO"""
+"""Main implementation of APIO INIT command"""
+
+from pathlib import Path
 
 import click
 
@@ -35,7 +37,7 @@
 @click.option(
     "-p",
     "--project-dir",
-    type=str,
+    type=Path,
     metavar="project_dir",
     help="Set the target directory for the project.",
 )
@@ -48,8 +50,13 @@
 def cli(ctx, board, top_module, scons, project_dir, sayyes):
     """Manage apio projects."""
 
+    # -- Create a project
+    project = Project()
+
+    # -- scons option: Create default SConstruct file
     if scons:
-        Project().create_sconstruct(project_dir, "ice40", sayyes)
+        project.create_sconstruct(project_dir, "ice40", sayyes)
+
     elif board:
         # -- Set the default top_module when creating the ini file
         if not top_module:
diff --git a/apio/managers/project.py b/apio/managers/project.py
index 9cf34e71..83d21a70 100644
--- a/apio/managers/project.py
+++ b/apio/managers/project.py
@@ -8,7 +8,7 @@
 import sys
 from os.path import isfile
 
-# from pathlib import Path
+from pathlib import Path
 
 # -- Config Parser: Use INI config files with easy
 # https://docs.python.org/3/library/configparser.html
@@ -32,7 +32,7 @@ def __init__(self):
         # -- Top module by default: main
         self.top_module = "main"
 
-    def create_sconstruct(self, project_dir="", arch=None, sayyes=False):
+    def create_sconstruct(self, project_dir: Path, arch=None, sayyes=False):
         """Creates a default SConstruct file"""
 
         project_dir = util.check_dir(project_dir)
diff --git a/apio/managers/scons.py b/apio/managers/scons.py
index c32d0d20..41385643 100644
--- a/apio/managers/scons.py
+++ b/apio/managers/scons.py
@@ -42,7 +42,7 @@
 class SCons:
     """Class for managing the scons tools"""
 
-    def __init__(self, project_dir=""):
+    def __init__(self, project_dir: Path):
         """Initialization:
         * project_dir: path where the sources are located
           If not given, the curent working dir is used
@@ -55,7 +55,7 @@ def __init__(self, project_dir=""):
         self.resources = Resources()
 
         # -- Project path is given
-        if project_dir is not None:
+        if not project_dir:
             # Check if it is a correct folder
             # (or create a new one)
             project_dir = util.check_dir(project_dir)
diff --git a/apio/util.py b/apio/util.py
index b53b6459..3493bb5d 100644
--- a/apio/util.py
+++ b/apio/util.py
@@ -668,9 +668,7 @@ def check_dir(_dir: Path) -> Path:
     """
 
     # -- If no path is given, get the current working directory
-    if _dir:
-        _dir = Path(_dir)
-    else:
+    if not _dir:
         _dir = Path.cwd()
 
     # -- Check if the path is a file or a folder