diff --git a/src/common/common.js b/src/common/common.js
index 09f742f2..ebb394d3 100644
--- a/src/common/common.js
+++ b/src/common/common.js
@@ -106,3 +106,8 @@ export const INPUT_TYPE = {
   FREE: 'free',
   DIMENSION: 'dimension',
 }
+
+export const POLYGON_TYPE = {
+  ROOF: 'roof',
+  TRESTLE: 'trestle',
+}