diff --git a/modules/brep/brep-builder.ts b/modules/brep/brep-builder.ts
index 480d458a..9c3fbbfc 100644
--- a/modules/brep/brep-builder.ts
+++ b/modules/brep/brep-builder.ts
@@ -29,14 +29,14 @@ export default class BrepBuilder {
     return this._loop.halfEdges[this._loop.halfEdges.length - 1];
   }
 
-  face(surface?: BrepSurface = null): BrepBuilder {
+  face(surface?: BrepSurface): BrepBuilder {
     this._face = new Face(surface ? surface : null);
     this._shell.faces.push(this._face);
     this._loop = null;
     return this;  
   }
 
-  loop(vertices: Vertex[]): BrepBuilder {
+  loop(vertices?: Vertex[]): BrepBuilder {
     if (this._loop === null) {
       this._loop = this._face.outerLoop;
     } else {
diff --git a/modules/brep/io/brepIO.ts b/modules/brep/io/brepIO.ts
index 535908f6..458bf6e8 100644
--- a/modules/brep/io/brepIO.ts
+++ b/modules/brep/io/brepIO.ts
@@ -1,7 +1,8 @@
-import BrepBuilder, {createBoundingSurfaceFrom2DPoints, createBoundingSurfaceFromBBox} from '../brep-builder';
+import BrepBuilder, {createBoundingSurfaceFromBBox} from '../brep-builder';
 import VertexFactory from '../vertexFactory';
 import NurbsSurface from 'geom/surfaces/nurbsSurface';
 import * as vec from 'math/vec';
+import {Vec3} from 'math/vec';
 import {BrepSurface} from 'geom/surfaces/brepSurface';
 import {Plane} from 'geom/impl/plane';
 import Vector from 'math/vector';
@@ -10,6 +11,49 @@ import BBox from 'math/bbox';
 import NurbsCurve from 'geom/curves/nurbsCurve';
 import BrepCurve from 'geom/curves/brepCurve';
 import {BREPData} from "../../../web/app/cad/craft/engine/brepData";
+import {ProductionInfo} from "../../../web/app/cad/craft/engine/productionInfo";
+import {Tessellation1D} from "../../../web/app/cad/craft/engine/tessellation";
+
+//Extensions for topo objects
+declare module '../topo/shell' {
+
+  interface Shell {
+    data: {
+      externals: {
+        ptr?: number
+      }
+    }
+  }
+}
+
+declare module '../topo/face' {
+
+  interface Face {
+    data: {
+      id: string,
+      productionInfo: ProductionInfo,
+      tessellation: {
+        format: string,
+        data: any;
+      }
+      externals: {
+        ref: number
+      }
+    }
+  }
+}
+
+declare module '../topo/edge' {
+
+  interface Edge {
+    data: {
+      tessellation: Tessellation1D<Vec3>
+      externals: {
+        ptr?: number
+      }
+    }
+  }
+}
 
 export function readBrep(data: BREPData) {
   
diff --git a/modules/brep/topo/face.ts b/modules/brep/topo/face.ts
index bae8bd46..707fb603 100644
--- a/modules/brep/topo/face.ts
+++ b/modules/brep/topo/face.ts
@@ -4,27 +4,9 @@ import PIP from '../../../web/app/cad/tess/pip';
 import {veq} from "geom/tolerance";
 import {isOnPositiveHalfPlaneFromVec} from "../operations/boolean";
 import {BrepSurface} from "geom/surfaces/brepSurface";
-import {edgesGenerator, Shell} from "./shell";
-import {ProductionInfo} from "../../../web/app/cad/craft/engine/productionInfo";
+import {Shell} from "./shell";
 import {HalfEdge} from "brep/topo/edge";
 
-declare module './face' {
-
-  interface Face {
-    data: {
-      id: string,
-      productionInfo: ProductionInfo,
-      tessellation: {
-        format: string,
-        data: any;
-      }
-      externals: {
-        ref: number
-      }
-    }
-  }
-}
-
 export class Face extends TopoObject {