diff --git a/archetypes.py b/archetypes.py
index ccefaeb..47efb56 100644
--- a/archetypes.py
+++ b/archetypes.py
@@ -1,9 +1,10 @@
-import configuration as c
-import xmltodict
 import json
 from urllib.request import urlopen
+
+import xmltodict
 from bs4 import BeautifulSoup
 
+import configuration as c
 
 print('start archetypes')
 
@@ -21,6 +22,10 @@ def process_formula(formula, hdd):
 with open(c.nrcan_urls, 'r') as f:
   urls = xmltodict.parse(f.read(), force_list=['standards_per_period'])
 
+with open(c.transparent_surfaces_path, 'r') as f:
+  transparent_surfaces = json.load(f)
+transparent_surfaces = [list(t.keys())[0] for t in transparent_surfaces['transparent_surfaces']]
+
 base_url_archetypes = urls['nrcan']['@base_url_archetypes']
 dictionary = {"archetypes": []}
 
@@ -28,7 +33,6 @@ standards = urls['nrcan']['standards_per_function']
 
 for standard in standards['standard']:
   archetype_url = f'{base_url_archetypes}{standard["file_location"]}'
-  print(archetype_url)
   html = urlopen(archetype_url).read()
   parsed_html = BeautifulSoup(html, features="html.parser")
   div = parsed_html.body.findAll('div', attrs={'class': 'in'})
@@ -82,16 +86,33 @@ for standard in standards['standard']:
           skylight_roof_ratio['west'] = cell
           found = False
       archetype["constructions"] = {}
-      archetype["constructions"]["OutdoorsWall"] = {
-        "opaque_surface_name": f'{period}_{climate_zone}',
-        "transparent_surface_name": f'Window_{period}_{climate_zone}',
-        "transparent_ratio": window_wall_ratio
-      }
-      archetype["constructions"]["OutdoorsRoofCeiling"] = {
-        "opaque_surface_name": f'{period}_{climate_zone}',
-        "transparent_surface_name": f'Skylight_{period}_{climate_zone}',
-        "transparent_ratio": skylight_roof_ratio
-      }
+      construction = f'Window_{period}_{climate_zone}'
+      if construction in transparent_surfaces:
+        archetype["constructions"]["OutdoorsWall"] = {
+          "opaque_surface_name": f'{period}_{climate_zone}',
+          "transparent_surface_name": f'Window_{period}_{climate_zone}',
+          "transparent_ratio": window_wall_ratio
+        }
+      else:
+        archetype["constructions"]["OutdoorsWall"] = {
+          "opaque_surface_name": f'{period}_{climate_zone}',
+          "transparent_surface_name": None,
+          "transparent_ratio": c.null_transparent_ratio
+        }
+      construction = f'Skylight_{period}_{climate_zone}'
+      if construction in transparent_surfaces:
+        archetype["constructions"]["OutdoorsRoofCeiling"] = {
+          "opaque_surface_name": f'{period}_{climate_zone}',
+          "transparent_surface_name": f'Skylight_{period}_{climate_zone}',
+          "transparent_ratio": skylight_roof_ratio
+        }
+      else:
+        archetype["constructions"]["OutdoorsRoofCeiling"] = {
+          "opaque_surface_name": f'{period}_{climate_zone}',
+          "transparent_surface_name": None,
+          "transparent_ratio": c.null_transparent_ratio
+        }
+
       archetype["constructions"]["OutdoorsFloor"] = {
         "opaque_surface_name": f'{period}_{climate_zone}'
       }
@@ -105,5 +126,5 @@ for standard in standards['standard']:
         "opaque_surface_name": f'{period}_{climate_zone}'
       }
       dictionary["archetypes"].append(archetype)
-with open(f'{c.output_path}/archetypes.json', 'w') as f:
+with open(f'{c.output_path}/nrcan_archetypes.json', 'w') as f:
   json.dump(dictionary, f, indent=2)
diff --git a/configuration.py b/configuration.py
index 6ef1933..be69858 100644
--- a/configuration.py
+++ b/configuration.py
@@ -3,6 +3,18 @@ from pathlib import Path
 data_path = Path('./data/').resolve()
 nrcan_urls = Path('./data/nrcan.xml')
 output_path = Path('./output/').resolve()
+transparent_surfaces_path = (output_path / 'transparent_surfaces.json').resolve()
+opaque_surfaces_path = (output_path / 'opaque_surfaces.json').resolve()
+
+nrcan_constructions = (output_path / 'nrcan_constructions.json').resolve()
+nrcan_archetypes = (output_path / 'nrcan_archetypes.json').resolve()
+
+null_transparent_ratio = {
+  "north": None,
+  "east": None,
+  "south": None,
+  "west": None
+}
 
 shgc_for_canadian_climate_zones = {'4': 0.39, '5': 0.39, '6': 0.39, '7A': 0.49, '7B': 0.49, '8': 0.41}
 
diff --git a/main.py b/main.py
index 1cfc9e2..260336a 100644
--- a/main.py
+++ b/main.py
@@ -1,5 +1,25 @@
+import os
+
 import opaque_surfaces
 import transparent_surfaces
 import archetypes
+import configuration as c
+import json
+
+print('compacting constructions')
+
+with open(c.opaque_surfaces_path, 'r') as f:
+  opaque = json.load(f)
+with open(c.transparent_surfaces_path, 'r') as f:
+  transparent = json.load(f)
+
+os.remove(str(c.opaque_surfaces_path))
+os.remove(str(c.transparent_surfaces_path))
+
+constructions = dict(opaque_surfaces=opaque['opaque_surfaces'], transparent_surfaces=transparent['transparent_surfaces'])
+
+with open(c.nrcan_constructions, 'w') as f:
+  json.dump(constructions, f)
+
 
 print('NRCAN catalog successfully created')