diff --git a/GeometryOpsCore/src/other_primitives.jl b/GeometryOpsCore/src/other_primitives.jl
index b0ac8c6b7..b51365e40 100644
--- a/GeometryOpsCore/src/other_primitives.jl
+++ b/GeometryOpsCore/src/other_primitives.jl
@@ -159,10 +159,21 @@ on geometries from other packages and specify how to rebuild them.
 rebuild(geom, child_geoms; kw...) = rebuild(GI.trait(geom), geom, child_geoms; kw...)
 function rebuild(trait::GI.AbstractTrait, geom, child_geoms; crs=GI.crs(geom), extent=nothing)
     T = GI.geointerface_geomtype(trait)
-    if GI.is3d(geom)
-        # The Boolean type parameters here indicate "3d-ness" and "measure" coordinate, respectively.
-        return T{true,false}(child_geoms; crs, extent)
-    else
-        return T{false,false}(child_geoms; crs, extent)
+    haveZ = (GI.is3d(child) for child in child_geoms)
+    haveM = (GI.ismeasured(child) for child in child_geoms)
+
+    consistentZ = length(child_geoms) == 1 ? true : all(==(first(haveZ)), haveZ)
+    consistentM = length(child_geoms) == 1 ? true : all(==(first(haveM)), haveM)
+
+    if !consistentZ || !consistentM
+        @show consistentZ consistentM
+        @show GI.is3d.(child_geoms)
+        @show GI.ismeasured.(child_geoms)
+        throw(ArgumentError("child geometries do not have consistent 3d or measure attributes."))
     end
+
+    hasZ = first(haveZ)
+    hasM = first(haveM)
+
+    return T{hasZ,hasM}(child_geoms; crs, extent)
 end
diff --git a/src/transformations/forcedims.jl b/src/transformations/forcedims.jl
new file mode 100644
index 000000000..d0525e214
--- /dev/null
+++ b/src/transformations/forcedims.jl
@@ -0,0 +1,5 @@
+function forcexy(geom)
+    return GO.apply(GO.GI.PointTrait(), geom) do point
+        (GI.x(point), GI.y(point))
+    end
+end