diff --git a/lca_carbon_workflow.py b/lca_carbon_workflow.py
index 7e01603..03ad7bf 100644
--- a/lca_carbon_workflow.py
+++ b/lca_carbon_workflow.py
@@ -74,13 +74,16 @@ class LCACarbonWorkflow:
 
       for boundary in surface.associated_thermal_boundaries:
         opening_emission = None
-        layer_emission = self._calculate_envelope_emission(boundary)
+        layer_emission, boundary_work_load = \
+            self._calculate_envelope_emission(boundary)
         boundary_envelope_emission += layer_emission
         boundary_volume.append(boundary.opaque_area * boundary.thickness)
 
         if boundary.window_ratio:
-          opening_emission = self._calculate_opening_emission(
-            building, surface, boundary, opaque_surface_code)
+          opening_emission, opening_workload = \
+            self._calculate_opening_emission(
+              building, surface, boundary, opaque_surface_code)
+          boundary_work_load += opening_workload
         if opening_emission:
           boundary_opening_emission += opening_emission
       if boundary_opening_emission:
@@ -96,6 +99,7 @@ class LCACarbonWorkflow:
 
   def _calculate_envelope_emission(self, boundary):
     layer_emission = []
+    boundary_workload = []
     for layer in boundary.layers:
       if not layer.no_mass:
         layer_material = \
@@ -103,12 +107,20 @@ class LCACarbonWorkflow:
         layer_emission.append(EnvelopeEmission(
           layer_material['embodied_carbon'],
           boundary.opaque_area, layer.thickness).calculate_envelope_emission())
-        layer_workload = boundary.opaque_area * layer.thickness *  layer_material['density']
-    return layer_emission
+        boundary_workload.append(
+          boundary.opaque_area * layer.thickness * layer_material['density'])
+    return layer_emission, sum(boundary_workload)
 
   def _calculate_opening_emission(
-          self, building, surface, boundary, opaque_surface_code):
+          self,
+          building, surface, boundary, opaque_surface_code,
+          density=2579):
+    """Windows have the assumed density of 2579 kg/m3
+       Window's thickness assumed the same as wall's thickness
+       These two values are being used to calculate window's workload
+       for End of Life emission evaluation."""
     opening_emission = []
+    window_workload = []
     for opening in boundary.thermal_openings:
       transparent_surface_type = 'Window'
       if building.year_of_construction >= 2020 and \
@@ -118,7 +130,8 @@ class LCACarbonWorkflow:
         self.nrcan_catalogs.search_transparent_surfaces(
           transparent_surface_type, opaque_surface_code)['embodied_carbon'],
         opening.area).calculate_opening_emission())
-    return opening_emission
+      window_workload.append(opening.area * boundary.thickness * density)
+    return opening_emission, sum(window_workload)
 
   def calculate_emission(self):
     for building in self.city.buildings: