diff --git a/lca_carbon_workflow.py b/lca_carbon_workflow.py
index 0b7e934..c51f270 100644
--- a/lca_carbon_workflow.py
+++ b/lca_carbon_workflow.py
@@ -54,6 +54,7 @@ class LCACarbonWorkflow:
     ConstructionFactory(self.handler, self.city).enrich()
 
   def calculate_building_component_emission(self, building):
+    surface_envelope_emission = []
     surface_opening_emission = []
     period_of_construction = self.nrcan_catalogs.year_to_period_of_construction(building.year_of_construction)
     print(period_of_construction)
@@ -65,31 +66,38 @@ class LCACarbonWorkflow:
       '6')
 
     for surface in building.surfaces:
+      boundary_envelope_emission = []
       boundary_opening_emission = []
       for boundary in surface.associated_thermal_boundaries:
-        opening_emission = []
-        layer_emission = []
-        if boundary.window_ratio == 0:
-          opening_surface = 0
-          opening_material_emission = 0
-          for layer in boundary.layers:
-            layer_emission.append(EnvelopeEmission(
-              self.nrcan_catalogs.search_materials(
-                layer.material_name)['embodied_carbon'],
-              boundary.opaque_area,
-              layer.thickness).calculate_envelope_emission())
-# continue from here, but remember, since the area of windows and opaque is at hand, we may not need a conditional for window_ratio
+        opening_emission = None
+        layer_emission = self._calculate_envelope_emission(boundary)
+        boundary_envelope_emission += layer_emission
 
-        else:
+        if boundary.window_ratio:
           opening_emission = self._calculate_opening_emission(
             building, surface, boundary, opaque_surface_code)
         if opening_emission:
           boundary_opening_emission += opening_emission
-        print('boundary_opening_emission', boundary_opening_emission)
       if boundary_opening_emission:
         surface_opening_emission += boundary_opening_emission
+      surface_envelope_emission += boundary_envelope_emission
+    building_envelope_emission = sum(surface_envelope_emission)
     building_opening_emission = sum(surface_opening_emission)
-    # print(building_opening_emission)
+    building_component_emission = \
+      building_envelope_emission + building_opening_emission
+    print('\t\t\tbuilding_envelope_emission', building_envelope_emission)
+    print('\t\t\tbuilding_opening_emission', building_opening_emission)
+    print('\t\t\t\tbuilding_component_emission', building_component_emission)
+
+  def _calculate_envelope_emission(self, boundary):
+    layer_emission = []
+    for layer in boundary.layers:
+      if not layer.no_mass:
+        layer_emission.append(EnvelopeEmission(
+          self.nrcan_catalogs.search_materials(
+            layer.material_name)['embodied_carbon'],
+          boundary.opaque_area, layer.thickness).calculate_envelope_emission())
+    return layer_emission
 
   def _calculate_opening_emission(
           self, building, surface, boundary, opaque_surface_code):
@@ -105,9 +113,6 @@ class LCACarbonWorkflow:
         opening.area).calculate_opening_emission())
     return opening_emission
 
-  def _calculate_envelope_emission(self):
-    pass
-
   def calculate_emission(self):
     for building in self.city.buildings:
       self.calculate_building_component_emission(building)