diff --git a/crates/fj-interop/src/ext.rs b/crates/fj-interop/src/ext.rs
index cc5e5311e..b4d562186 100644
--- a/crates/fj-interop/src/ext.rs
+++ b/crates/fj-interop/src/ext.rs
@@ -13,6 +13,11 @@ pub trait ArrayExt<T, const N: usize> {
     fn try_map_ext<F, U, E>(self, f: F) -> Result<[U; N], E>
     where
         F: FnMut(T) -> Result<U, E>;
+
+    /// Stable replacement for `zip`
+    ///
+    /// <https://doc.rust-lang.org/std/primitive.array.html#method.zip>
+    fn zip_ext<U>(self, rhs: [U; N]) -> [(T, U); N];
 }
 
 impl<T> ArrayExt<T, 2> for [T; 2] {
@@ -28,6 +33,12 @@ impl<T> ArrayExt<T, 2> for [T; 2] {
         let [a, b] = self.map(f);
         Ok([a?, b?])
     }
+
+    fn zip_ext<U>(self, rhs: [U; 2]) -> [(T, U); 2] {
+        let [a, b] = self;
+        let [q, r] = rhs;
+        [(a, q), (b, r)]
+    }
 }
 
 impl<T> ArrayExt<T, 4> for [T; 4] {
@@ -43,6 +54,12 @@ impl<T> ArrayExt<T, 4> for [T; 4] {
         let [a, b, c, d] = self.map(f);
         Ok([a?, b?, c?, d?])
     }
+
+    fn zip_ext<U>(self, rhs: [U; 4]) -> [(T, U); 4] {
+        let [a, b, c, d] = self;
+        let [q, r, s, t] = rhs;
+        [(a, q), (b, r), (c, s), (d, t)]
+    }
 }
 
 /// Extension trait for arrays
diff --git a/crates/fj-kernel/src/builder/edge.rs b/crates/fj-kernel/src/builder/edge.rs
index 0f44ee1f6..be090554f 100644
--- a/crates/fj-kernel/src/builder/edge.rs
+++ b/crates/fj-kernel/src/builder/edge.rs
@@ -1,3 +1,4 @@
+use fj_interop::ext::ArrayExt;
 use fj_math::{Point, Scalar};
 use iter_fixed::IntoIteratorFixed;
 
@@ -6,7 +7,7 @@ use crate::{
     objects::{Curve, Objects, Surface, Vertex, VerticesInNormalizedOrder},
     partial::{
         MaybePartial, MergeWith, PartialGlobalEdge, PartialHalfEdge,
-        PartialSurfaceVertex, PartialVertex, Replace,
+        PartialSurfaceVertex, PartialVertex,
     },
     services::{Service, Services},
     storage::Handle,
@@ -108,21 +109,18 @@ impl HalfEdgeBuilder for PartialHalfEdge {
         surface: Handle<Surface>,
         points: [impl Into<Point<2>>; 2],
     ) -> Self {
-        let vertices = points.map(|point| {
-            let surface_form = PartialSurfaceVertex {
+        self.vertices = self.vertices.zip_ext(points).map(|(vertex, point)| {
+            let mut vertex = vertex.into_partial();
+
+            vertex.surface_form = MaybePartial::from(PartialSurfaceVertex {
                 position: Some(point.into()),
                 surface: Some(surface.clone()),
                 ..Default::default()
-            };
+            });
 
-            PartialVertex {
-                surface_form: surface_form.into(),
-                ..Default::default()
-            }
+            vertex.into()
         });
 
-        self.replace(surface);
-        self.vertices = vertices.map(Into::into);
         self.update_as_line_segment()
     }
 
diff --git a/crates/fj-kernel/src/partial/objects/cycle.rs b/crates/fj-kernel/src/partial/objects/cycle.rs
index beee8a0b5..be6341c69 100644
--- a/crates/fj-kernel/src/partial/objects/cycle.rs
+++ b/crates/fj-kernel/src/partial/objects/cycle.rs
@@ -1,9 +1,7 @@
 use crate::{
     builder::HalfEdgeBuilder,
     objects::{Cycle, HalfEdge, Objects, Surface},
-    partial::{
-        MaybePartial, MergeWith, PartialHalfEdge, PartialVertex, Replace,
-    },
+    partial::{MaybePartial, MergeWith, PartialHalfEdge, PartialVertex},
     services::Service,
     storage::Handle,
 };
@@ -49,22 +47,6 @@ impl PartialCycle {
             self.half_edges.push(half_edge);
         }
 
-        self.with_surface(surface)
-    }
-
-    /// Update the partial cycle with the provided surface
-    ///
-    /// All [`HalfEdge`]s will be updated with this surface.
-    pub fn with_surface(mut self, surface: Option<Handle<Surface>>) -> Self {
-        if let Some(surface) = surface {
-            for half_edge in &mut self.half_edges {
-                *half_edge =
-                    half_edge.clone().update_partial(|mut half_edge| {
-                        half_edge.replace(surface.clone());
-                        half_edge
-                    });
-            }
-        }
         self
     }
 
diff --git a/crates/fj-kernel/src/partial/objects/vertex.rs b/crates/fj-kernel/src/partial/objects/vertex.rs
index 1cfff018b..22c2fe6ad 100644
--- a/crates/fj-kernel/src/partial/objects/vertex.rs
+++ b/crates/fj-kernel/src/partial/objects/vertex.rs
@@ -69,8 +69,7 @@ impl MergeWith for PartialVertex {
 
 impl Replace<Surface> for PartialVertex {
     fn replace(&mut self, surface: Handle<Surface>) -> &mut Self {
-        self.curve.replace(surface.clone());
-        self.surface_form.replace(surface);
+        self.curve.replace(surface);
         self
     }
 }
@@ -136,13 +135,6 @@ impl MergeWith for PartialSurfaceVertex {
     }
 }
 
-impl Replace<Surface> for PartialSurfaceVertex {
-    fn replace(&mut self, surface: Handle<Surface>) -> &mut Self {
-        self.surface = Some(surface);
-        self
-    }
-}
-
 impl From<&SurfaceVertex> for PartialSurfaceVertex {
     fn from(surface_vertex: &SurfaceVertex) -> Self {
         Self {