diff --git a/crates/fj-kernel/src/algorithms/intersect/curve_face.rs b/crates/fj-kernel/src/algorithms/intersect/curve_face.rs
index 856f76b29..7cb42d0dc 100644
--- a/crates/fj-kernel/src/algorithms/intersect/curve_face.rs
+++ b/crates/fj-kernel/src/algorithms/intersect/curve_face.rs
@@ -150,8 +150,9 @@ where
 #[cfg(test)]
 mod tests {
     use crate::{
-        builder::{CycleBuilder, FaceBuilder},
         geometry::curve::Curve,
+        objects::{Cycle, Face},
+        operations::{BuildCycle, BuildFace, Insert, UpdateFace},
         services::Services,
     };
 
@@ -178,20 +179,23 @@ mod tests {
             [ 1., -1.],
         ];
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                exterior_points,
-                &mut services,
-            ))
-            .with_interior(CycleBuilder::polygon(
-                interior_points,
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(exterior_points, &mut services)
+                        .insert(&mut services)
+                })
+                .add_interiors([Cycle::polygon(
+                    interior_points,
+                    &mut services,
+                )
+                .insert(&mut services)]);
 
         let expected =
             CurveFaceIntersection::from_intervals([[[1.], [2.]], [[4.], [5.]]]);
         assert_eq!(CurveFaceIntersection::compute(&curve, &face), expected);
+
+        services.only_validate(face);
     }
 
     #[test]
diff --git a/crates/fj-kernel/src/algorithms/intersect/face_face.rs b/crates/fj-kernel/src/algorithms/intersect/face_face.rs
index 931af8fc8..dae7f0d6e 100644
--- a/crates/fj-kernel/src/algorithms/intersect/face_face.rs
+++ b/crates/fj-kernel/src/algorithms/intersect/face_face.rs
@@ -62,8 +62,9 @@ mod tests {
 
     use crate::{
         algorithms::intersect::CurveFaceIntersection,
-        builder::{CycleBuilder, FaceBuilder},
         geometry::curve::Curve,
+        objects::{Cycle, Face},
+        operations::{BuildCycle, BuildFace, Insert, UpdateFace},
         services::Services,
     };
 
@@ -85,14 +86,15 @@ mod tests {
             services.objects.surfaces.xz_plane(),
         ]
         .map(|surface| {
-            FaceBuilder::new(surface)
-                .with_exterior(CycleBuilder::polygon(points, &mut services))
-                .build(&mut services)
+            Face::unbound(surface, &mut services).update_exterior(|_| {
+                Cycle::polygon(points, &mut services).insert(&mut services)
+            })
         });
 
         let intersection = FaceFaceIntersection::compute([&a, &b]);
-
         assert!(intersection.is_none());
+
+        services.only_validate([a, b]);
     }
 
     #[test]
@@ -111,9 +113,9 @@ mod tests {
             services.objects.surfaces.xz_plane(),
         ];
         let [a, b] = surfaces.clone().map(|surface| {
-            FaceBuilder::new(surface)
-                .with_exterior(CycleBuilder::polygon(points, &mut services))
-                .build(&mut services)
+            Face::unbound(surface, &mut services).update_exterior(|_| {
+                Cycle::polygon(points, &mut services).insert(&mut services)
+            })
         });
 
         let intersection = FaceFaceIntersection::compute([&a, &b]);
@@ -131,5 +133,7 @@ mod tests {
                 intersection_intervals: expected_intervals
             })
         );
+
+        services.only_validate([a, b]);
     }
 }
diff --git a/crates/fj-kernel/src/algorithms/intersect/face_point.rs b/crates/fj-kernel/src/algorithms/intersect/face_point.rs
index 109543316..474d0ec00 100644
--- a/crates/fj-kernel/src/algorithms/intersect/face_point.rs
+++ b/crates/fj-kernel/src/algorithms/intersect/face_point.rs
@@ -138,7 +138,8 @@ mod tests {
 
     use crate::{
         algorithms::intersect::{face_point::FacePointIntersection, Intersect},
-        builder::{CycleBuilder, FaceBuilder},
+        objects::{Cycle, Face},
+        operations::{BuildCycle, BuildFace, Insert, UpdateFace},
         services::Services,
     };
 
@@ -146,28 +147,36 @@ mod tests {
     fn point_is_outside_face() {
         let mut services = Services::new();
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[0., 0.], [1., 1.], [0., 2.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[0., 0.], [1., 1.], [0., 2.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let point = Point::from([2., 1.]);
 
         let intersection = (&face, &point).intersect();
         assert_eq!(intersection, None);
+
+        services.only_validate(face);
     }
 
     #[test]
     fn ray_hits_vertex_while_passing_outside() {
         let mut services = Services::new();
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[0., 0.], [2., 1.], [0., 2.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[0., 0.], [2., 1.], [0., 2.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let point = Point::from([1., 1.]);
 
         let intersection = (&face, &point).intersect();
@@ -175,18 +184,23 @@ mod tests {
             intersection,
             Some(FacePointIntersection::PointIsInsideFace)
         );
+
+        services.only_validate(face);
     }
 
     #[test]
     fn ray_hits_vertex_at_cycle_seam() {
         let mut services = Services::new();
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[4., 2.], [0., 4.], [0., 0.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[4., 2.], [0., 4.], [0., 0.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let point = Point::from([1., 2.]);
 
         let intersection = (&face, &point).intersect();
@@ -194,18 +208,23 @@ mod tests {
             intersection,
             Some(FacePointIntersection::PointIsInsideFace)
         );
+
+        services.only_validate(face);
     }
 
     #[test]
     fn ray_hits_vertex_while_staying_inside() {
         let mut services = Services::new();
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[0., 0.], [2., 1.], [3., 0.], [3., 4.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[0., 0.], [2., 1.], [3., 0.], [3., 4.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let point = Point::from([1., 1.]);
 
         let intersection = (&face, &point).intersect();
@@ -213,18 +232,23 @@ mod tests {
             intersection,
             Some(FacePointIntersection::PointIsInsideFace)
         );
+
+        services.only_validate(face);
     }
 
     #[test]
     fn ray_hits_parallel_edge_and_leaves_face_at_vertex() {
         let mut services = Services::new();
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[0., 0.], [2., 1.], [3., 1.], [0., 2.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[0., 0.], [2., 1.], [3., 1.], [0., 2.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let point = Point::from([1., 1.]);
 
         let intersection = (&face, &point).intersect();
@@ -232,18 +256,23 @@ mod tests {
             intersection,
             Some(FacePointIntersection::PointIsInsideFace)
         );
+
+        services.only_validate(face);
     }
 
     #[test]
     fn ray_hits_parallel_edge_and_does_not_leave_face_there() {
         let mut services = Services::new();
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[0., 0.], [2., 1.], [3., 1.], [4., 0.], [4., 5.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[0., 0.], [2., 1.], [3., 1.], [4., 0.], [4., 5.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let point = Point::from([1., 1.]);
 
         let intersection = (&face, &point).intersect();
@@ -251,18 +280,23 @@ mod tests {
             intersection,
             Some(FacePointIntersection::PointIsInsideFace)
         );
+
+        services.only_validate(face);
     }
 
     #[test]
     fn point_is_coincident_with_edge() {
         let mut services = Services::new();
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[0., 0.], [2., 0.], [0., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[0., 0.], [2., 0.], [0., 1.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let point = Point::from([1., 0.]);
 
         let intersection = (&face, &point).intersect();
@@ -276,18 +310,23 @@ mod tests {
             intersection,
             Some(FacePointIntersection::PointIsOnEdge(edge.clone()))
         );
+
+        services.only_validate(face);
     }
 
     #[test]
     fn point_is_coincident_with_vertex() {
         let mut services = Services::new();
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[0., 0.], [1., 0.], [0., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[0., 0.], [1., 0.], [0., 1.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let point = Point::from([1., 0.]);
 
         let intersection = (&face, &point).intersect();
@@ -304,5 +343,7 @@ mod tests {
             intersection,
             Some(FacePointIntersection::PointIsOnVertex(vertex))
         );
+
+        services.only_validate(face);
     }
 }
diff --git a/crates/fj-kernel/src/algorithms/intersect/ray_face.rs b/crates/fj-kernel/src/algorithms/intersect/ray_face.rs
index 97afca4f5..d4a8b141d 100644
--- a/crates/fj-kernel/src/algorithms/intersect/ray_face.rs
+++ b/crates/fj-kernel/src/algorithms/intersect/ray_face.rs
@@ -152,7 +152,8 @@ mod tests {
             },
             transform::TransformObject,
         },
-        builder::{CycleBuilder, FaceBuilder},
+        objects::{Cycle, Face},
+        operations::{BuildCycle, BuildFace, Insert, UpdateFace},
         services::Services,
     };
 
@@ -162,15 +163,20 @@ mod tests {
 
         let ray = HorizontalRayToTheRight::from([0., 0., 0.]);
 
-        let face = FaceBuilder::new(services.objects.surfaces.yz_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.yz_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let face = face.translate([-1., 0., 0.], &mut services);
 
         assert_eq!((&ray, &face).intersect(), None);
+
+        services.only_validate(face);
     }
 
     #[test]
@@ -179,18 +185,23 @@ mod tests {
 
         let ray = HorizontalRayToTheRight::from([0., 0., 0.]);
 
-        let face = FaceBuilder::new(services.objects.surfaces.yz_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.yz_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let face = face.translate([1., 0., 0.], &mut services);
 
         assert_eq!(
             (&ray, &face).intersect(),
             Some(RayFaceIntersection::RayHitsFace)
         );
+
+        services.only_validate(face);
     }
 
     #[test]
@@ -199,15 +210,20 @@ mod tests {
 
         let ray = HorizontalRayToTheRight::from([0., 0., 0.]);
 
-        let face = FaceBuilder::new(services.objects.surfaces.yz_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.yz_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let face = face.translate([0., 0., 2.], &mut services);
 
         assert_eq!((&ray, &face).intersect(), None);
+
+        services.only_validate(face);
     }
 
     #[test]
@@ -216,12 +232,15 @@ mod tests {
 
         let ray = HorizontalRayToTheRight::from([0., 0., 0.]);
 
-        let face = FaceBuilder::new(services.objects.surfaces.yz_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.yz_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let face = face.translate([1., 1., 0.], &mut services);
 
         let edge = face
@@ -233,6 +252,8 @@ mod tests {
             (&ray, &face).intersect(),
             Some(RayFaceIntersection::RayHitsEdge(edge.clone()))
         );
+
+        services.only_validate(face);
     }
 
     #[test]
@@ -241,12 +262,15 @@ mod tests {
 
         let ray = HorizontalRayToTheRight::from([0., 0., 0.]);
 
-        let face = FaceBuilder::new(services.objects.surfaces.yz_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.yz_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let face = face.translate([1., 1., 1.], &mut services);
 
         let vertex = face
@@ -261,6 +285,8 @@ mod tests {
             (&ray, &face).intersect(),
             Some(RayFaceIntersection::RayHitsVertex(vertex))
         );
+
+        services.only_validate(face);
     }
 
     #[test]
@@ -269,17 +295,22 @@ mod tests {
 
         let ray = HorizontalRayToTheRight::from([0., 0., 0.]);
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
 
         assert_eq!(
             (&ray, &face).intersect(),
             Some(RayFaceIntersection::RayHitsFaceAndAreParallel)
         );
+
+        services.only_validate(face);
     }
 
     #[test]
@@ -288,14 +319,19 @@ mod tests {
 
         let ray = HorizontalRayToTheRight::from([0., 0., 0.]);
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[-1., -1.], [1., -1.], [1., 1.], [-1., 1.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                });
         let face = face.translate([0., 0., 1.], &mut services);
 
         assert_eq!((&ray, &face).intersect(), None);
+
+        services.only_validate(face);
     }
 }
diff --git a/crates/fj-kernel/src/algorithms/triangulate/mod.rs b/crates/fj-kernel/src/algorithms/triangulate/mod.rs
index 7e8f5b731..b585ac229 100644
--- a/crates/fj-kernel/src/algorithms/triangulate/mod.rs
+++ b/crates/fj-kernel/src/algorithms/triangulate/mod.rs
@@ -79,8 +79,8 @@ mod tests {
 
     use crate::{
         algorithms::approx::{Approx, Tolerance},
-        builder::{CycleBuilder, FaceBuilder},
-        objects::Face,
+        objects::{Cycle, Face},
+        operations::{BuildCycle, BuildFace, Insert, UpdateFace},
         services::Services,
     };
 
@@ -95,9 +95,13 @@ mod tests {
         let c = [2., 2.];
         let d = [0., 1.];
 
-        let face = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon([a, b, c, d], &mut services))
-            .build(&mut services);
+        let face =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon([a, b, c, d], &mut services)
+                        .insert(&mut services)
+                });
+        services.only_validate(&face);
 
         let a = Point::from(a).to_xyz();
         let b = Point::from(b).to_xyz();
@@ -130,10 +134,14 @@ mod tests {
 
         let surface = services.objects.surfaces.xy_plane();
 
-        let face = FaceBuilder::new(surface.clone())
-            .with_exterior(CycleBuilder::polygon([a, b, c, d], &mut services))
-            .with_interior(CycleBuilder::polygon([e, f, g, h], &mut services))
-            .build(&mut services);
+        let face = Face::unbound(surface.clone(), &mut services)
+            .update_exterior(|_| {
+                Cycle::polygon([a, b, c, d], &mut services)
+                    .insert(&mut services)
+            })
+            .add_interiors([Cycle::polygon([e, f, g, h], &mut services)
+                .insert(&mut services)]);
+        services.only_validate(&face);
 
         let triangles = triangulate(face)?;
 
@@ -188,12 +196,12 @@ mod tests {
 
         let surface = services.objects.surfaces.xy_plane();
 
-        let face = FaceBuilder::new(surface.clone())
-            .with_exterior(CycleBuilder::polygon(
-                [a, b, c, d, e],
-                &mut services,
-            ))
-            .build(&mut services);
+        let face = Face::unbound(surface.clone(), &mut services)
+            .update_exterior(|_| {
+                Cycle::polygon([a, b, c, d, e], &mut services)
+                    .insert(&mut services)
+            });
+        services.only_validate(&face);
 
         let triangles = triangulate(face)?;
 
diff --git a/crates/fj-kernel/src/builder/face.rs b/crates/fj-kernel/src/builder/face.rs
deleted file mode 100644
index 7dd955e9c..000000000
--- a/crates/fj-kernel/src/builder/face.rs
+++ /dev/null
@@ -1,58 +0,0 @@
-use fj_interop::mesh::Color;
-
-use crate::{
-    objects::{Face, Surface},
-    operations::Insert,
-    services::Services,
-    storage::Handle,
-};
-
-use super::CycleBuilder;
-
-/// Builder API for [`Face`]
-pub struct FaceBuilder {
-    surface: Handle<Surface>,
-    exterior: CycleBuilder,
-    interiors: Vec<CycleBuilder>,
-    color: Option<Color>,
-}
-impl FaceBuilder {
-    /// Create an instance of `FaceBuilder`
-    pub fn new(surface: Handle<Surface>) -> Self {
-        Self {
-            surface,
-            exterior: CycleBuilder::new(),
-            interiors: Vec::new(),
-            color: None,
-        }
-    }
-
-    /// Replace the face's exterior cycle
-    pub fn with_exterior(mut self, exterior: CycleBuilder) -> Self {
-        self.exterior = exterior;
-        self
-    }
-
-    /// Add an interior cycle to the face
-    pub fn with_interior(mut self, interior: CycleBuilder) -> Self {
-        self.interiors.push(interior);
-        self
-    }
-
-    /// Define the color of the face
-    pub fn with_color(mut self, color: Color) -> Self {
-        self.color = Some(color);
-        self
-    }
-
-    /// Build the face
-    pub fn build(self, services: &mut Services) -> Face {
-        let exterior = self.exterior.build(services).insert(services);
-        let interiors = self
-            .interiors
-            .into_iter()
-            .map(|cycle| cycle.build(services).insert(services));
-
-        Face::new(self.surface, exterior, interiors, self.color)
-    }
-}
diff --git a/crates/fj-kernel/src/builder/mod.rs b/crates/fj-kernel/src/builder/mod.rs
index 067bb759d..453523ff1 100644
--- a/crates/fj-kernel/src/builder/mod.rs
+++ b/crates/fj-kernel/src/builder/mod.rs
@@ -1,6 +1,5 @@
 //! API for building objects
 
 mod cycle;
-mod face;
 
-pub use self::{cycle::CycleBuilder, face::FaceBuilder};
+pub use self::cycle::CycleBuilder;
diff --git a/crates/fj-kernel/src/objects/mod.rs b/crates/fj-kernel/src/objects/mod.rs
index 6c19fa57f..3964e9f5e 100644
--- a/crates/fj-kernel/src/objects/mod.rs
+++ b/crates/fj-kernel/src/objects/mod.rs
@@ -75,6 +75,7 @@
 
 mod full;
 mod object;
+mod set;
 mod stores;
 
 pub use self::{
@@ -89,5 +90,6 @@ pub use self::{
         vertex::Vertex,
     },
     object::{Bare, BehindHandle, Form, Object, WithHandle},
+    set::ObjectSet,
     stores::{Objects, Surfaces},
 };
diff --git a/crates/fj-kernel/src/objects/set.rs b/crates/fj-kernel/src/objects/set.rs
new file mode 100644
index 000000000..23ae75202
--- /dev/null
+++ b/crates/fj-kernel/src/objects/set.rs
@@ -0,0 +1,106 @@
+use std::collections::{btree_set, BTreeSet};
+
+use super::{
+    BehindHandle, Cycle, Face, GlobalEdge, HalfEdge, Object, Surface, Vertex,
+};
+
+/// A graph of objects and their relationships
+pub struct ObjectSet {
+    inner: BTreeSet<Object<BehindHandle>>,
+}
+
+impl From<&Face> for ObjectSet {
+    fn from(face: &Face) -> Self {
+        let mut self_ = Self {
+            inner: BTreeSet::new(),
+        };
+
+        face.insert_into_set(&mut self_);
+
+        self_
+    }
+}
+
+impl From<Face> for ObjectSet {
+    fn from(face: Face) -> Self {
+        Self::from(&face)
+    }
+}
+
+impl<Faces> From<Faces> for ObjectSet
+where
+    Faces: IntoIterator<Item = Face>,
+{
+    fn from(faces: Faces) -> Self {
+        let mut self_ = Self {
+            inner: BTreeSet::new(),
+        };
+
+        for face in faces {
+            face.insert_into_set(&mut self_);
+        }
+
+        self_
+    }
+}
+
+impl IntoIterator for ObjectSet {
+    type Item = Object<BehindHandle>;
+    type IntoIter = btree_set::IntoIter<Self::Item>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.inner.into_iter()
+    }
+}
+
+trait InsertIntoSet {
+    fn insert_into_set(&self, objects: &mut ObjectSet);
+}
+
+impl InsertIntoSet for Cycle {
+    fn insert_into_set(&self, objects: &mut ObjectSet) {
+        for half_edge in self.half_edges() {
+            objects.inner.insert(half_edge.clone().into());
+            half_edge.insert_into_set(objects);
+        }
+    }
+}
+
+impl InsertIntoSet for Face {
+    fn insert_into_set(&self, objects: &mut ObjectSet) {
+        objects.inner.insert(self.surface().clone().into());
+        self.surface().insert_into_set(objects);
+
+        objects.inner.insert(self.exterior().clone().into());
+        self.exterior().insert_into_set(objects);
+
+        for interior in self.interiors() {
+            objects.inner.insert(interior.clone().into());
+        }
+        for interior in self.interiors() {
+            interior.insert_into_set(objects);
+        }
+    }
+}
+
+impl InsertIntoSet for GlobalEdge {
+    fn insert_into_set(&self, _: &mut ObjectSet) {}
+}
+
+impl InsertIntoSet for HalfEdge {
+    fn insert_into_set(&self, objects: &mut ObjectSet) {
+        objects.inner.insert(self.start_vertex().clone().into());
+        self.start_vertex().insert_into_set(objects);
+
+        objects.inner.insert(self.global_form().clone().into());
+        self.global_form().insert_into_set(objects);
+    }
+}
+
+impl InsertIntoSet for Surface {
+    fn insert_into_set(&self, _: &mut ObjectSet) {}
+}
+
+impl InsertIntoSet for Vertex {
+    fn insert_into_set(&self, _: &mut ObjectSet) {}
+}
diff --git a/crates/fj-kernel/src/operations/build/face.rs b/crates/fj-kernel/src/operations/build/face.rs
index 047b1232a..57a5de45a 100644
--- a/crates/fj-kernel/src/operations/build/face.rs
+++ b/crates/fj-kernel/src/operations/build/face.rs
@@ -8,10 +8,16 @@ use crate::{
     storage::Handle,
 };
 
-use super::{BuildHalfEdge, BuildSurface};
+use super::{BuildCycle, BuildHalfEdge, BuildSurface};
 
 /// Build a [`Face`]
 pub trait BuildFace {
+    /// Build a face with an empty exterior, no interiors, and no color
+    fn unbound(surface: Handle<Surface>, services: &mut Services) -> Face {
+        let exterior = Cycle::empty().insert(services);
+        Face::new(surface, exterior, [], None)
+    }
+
     /// Build a triangle
     fn triangle(
         points: [impl Into<Point<3>>; 3],
diff --git a/crates/fj-kernel/src/operations/update/face.rs b/crates/fj-kernel/src/operations/update/face.rs
index 8c29847a1..2de785677 100644
--- a/crates/fj-kernel/src/operations/update/face.rs
+++ b/crates/fj-kernel/src/operations/update/face.rs
@@ -10,6 +10,12 @@ pub trait UpdateFace {
         &self,
         f: impl FnOnce(&Handle<Cycle>) -> Handle<Cycle>,
     ) -> Self;
+
+    /// Add the provides interiors to the face
+    fn add_interiors(
+        &self,
+        interiors: impl IntoIterator<Item = Handle<Cycle>>,
+    ) -> Self;
 }
 
 impl UpdateFace for Face {
@@ -26,4 +32,18 @@ impl UpdateFace for Face {
             self.color(),
         )
     }
+
+    fn add_interiors(
+        &self,
+        interiors: impl IntoIterator<Item = Handle<Cycle>>,
+    ) -> Self {
+        let interiors = self.interiors().cloned().chain(interiors);
+
+        Face::new(
+            self.surface().clone(),
+            self.exterior().clone(),
+            interiors,
+            self.color(),
+        )
+    }
 }
diff --git a/crates/fj-kernel/src/services/mod.rs b/crates/fj-kernel/src/services/mod.rs
index 79482136d..71c3310d2 100644
--- a/crates/fj-kernel/src/services/mod.rs
+++ b/crates/fj-kernel/src/services/mod.rs
@@ -6,7 +6,7 @@ mod objects;
 mod service;
 mod validation;
 
-use crate::objects::{Object, Objects, WithHandle};
+use crate::objects::{Object, ObjectSet, Objects, WithHandle};
 
 pub use self::{
     objects::{InsertObject, Operation},
@@ -52,6 +52,15 @@ impl Services {
             self.validation.execute(command, &mut Vec::new());
         }
     }
+
+    /// Validate the provided objects and forget all other validation errors
+    pub fn only_validate(&mut self, objects: impl Into<ObjectSet>) {
+        let objects = objects.into();
+
+        let mut events = Vec::new();
+        self.validation
+            .execute(ValidationCommand::OnlyValidate { objects }, &mut events);
+    }
 }
 
 impl Default for Services {
diff --git a/crates/fj-kernel/src/services/validation.rs b/crates/fj-kernel/src/services/validation.rs
index 326ff8738..afa3b59e9 100644
--- a/crates/fj-kernel/src/services/validation.rs
+++ b/crates/fj-kernel/src/services/validation.rs
@@ -1,7 +1,7 @@
 use std::{collections::BTreeMap, thread};
 
 use crate::{
-    objects::{BehindHandle, Object},
+    objects::{BehindHandle, Object, ObjectSet},
     storage::ObjectId,
     validate::ValidationError,
 };
@@ -39,16 +39,33 @@ impl State for Validation {
     type Event = ValidationEvent;
 
     fn decide(&self, command: Self::Command, events: &mut Vec<Self::Event>) {
-        let ValidationCommand::ValidateObject { object } = command;
-
         let mut errors = Vec::new();
-        object.validate(&mut errors);
 
-        for err in errors {
-            events.push(ValidationEvent::ValidationFailed {
-                object: object.clone(),
-                err,
-            });
+        match command {
+            ValidationCommand::ValidateObject { object } => {
+                object.validate(&mut errors);
+
+                for err in errors {
+                    events.push(ValidationEvent::ValidationFailed {
+                        object: object.clone(),
+                        err,
+                    });
+                }
+            }
+            ValidationCommand::OnlyValidate { objects } => {
+                events.push(ValidationEvent::ClearErrors);
+
+                for object in objects {
+                    object.validate(&mut errors);
+
+                    for err in errors.drain(..) {
+                        events.push(ValidationEvent::ValidationFailed {
+                            object: object.clone(),
+                            err,
+                        });
+                    }
+                }
+            }
         }
     }
 
@@ -57,6 +74,7 @@ impl State for Validation {
             ValidationEvent::ValidationFailed { object, err } => {
                 self.errors.insert(object.id(), err.clone());
             }
+            ValidationEvent::ClearErrors => self.errors.clear(),
         }
     }
 }
@@ -68,6 +86,12 @@ pub enum ValidationCommand {
         /// The object to validate
         object: Object<BehindHandle>,
     },
+
+    /// Validate the provided objects, discard all other validation errors
+    OnlyValidate {
+        /// The objects to validate
+        objects: ObjectSet,
+    },
 }
 
 /// The event produced by the validation service
@@ -81,4 +105,7 @@ pub enum ValidationEvent {
         /// The validation error
         err: ValidationError,
     },
+
+    /// All stored validation errors are being cleared
+    ClearErrors,
 }
diff --git a/crates/fj-kernel/src/validate/face.rs b/crates/fj-kernel/src/validate/face.rs
index 7b45fd64a..33b31c0f9 100644
--- a/crates/fj-kernel/src/validate/face.rs
+++ b/crates/fj-kernel/src/validate/face.rs
@@ -73,8 +73,8 @@ mod tests {
     use crate::{
         algorithms::reverse::Reverse,
         assert_contains_err,
-        builder::{CycleBuilder, FaceBuilder},
-        objects::Face,
+        objects::{Cycle, Face},
+        operations::{BuildCycle, BuildFace, Insert, UpdateFace},
         services::Services,
         validate::{FaceValidationError, Validate, ValidationError},
     };
@@ -83,16 +83,20 @@ mod tests {
     fn face_invalid_interior_winding() -> anyhow::Result<()> {
         let mut services = Services::new();
 
-        let valid = FaceBuilder::new(services.objects.surfaces.xy_plane())
-            .with_exterior(CycleBuilder::polygon(
-                [[0., 0.], [3., 0.], [0., 3.]],
-                &mut services,
-            ))
-            .with_interior(CycleBuilder::polygon(
-                [[1., 1.], [1., 2.], [2., 1.]],
-                &mut services,
-            ))
-            .build(&mut services);
+        let valid =
+            Face::unbound(services.objects.surfaces.xy_plane(), &mut services)
+                .update_exterior(|_| {
+                    Cycle::polygon(
+                        [[0., 0.], [3., 0.], [0., 3.]],
+                        &mut services,
+                    )
+                    .insert(&mut services)
+                })
+                .add_interiors([Cycle::polygon(
+                    [[1., 1.], [1., 2.], [2., 1.]],
+                    &mut services,
+                )
+                .insert(&mut services)]);
         let invalid = {
             let interiors = valid
                 .interiors()
@@ -116,6 +120,8 @@ mod tests {
             )
         );
 
+        services.only_validate(valid);
+
         Ok(())
     }
 }