diff --git a/src/blenderbim/blenderbim/bim/module/pset/calc_quantity_function_mapper.py b/src/blenderbim/blenderbim/bim/module/pset/calc_quantity_function_mapper.py
index f25da588ec..a2f00eba76 100644
--- a/src/blenderbim/blenderbim/bim/module/pset/calc_quantity_function_mapper.py
+++ b/src/blenderbim/blenderbim/bim/module/pset/calc_quantity_function_mapper.py
@@ -65,10 +65,10 @@ mapper = {
         'GrossWeight' : None,
     },
     'Qto_DoorBaseQuantities' : {
-        'Width' : None,
-        'Height' : None,
-        'Perimeter' : None,
-        'Area' : None,
+        'Width' : { "function_name" : "get_length", "args" : ", main_axis = 'x'"},
+        'Height' : "get_height",
+        'Perimeter' : "get_rectangular_perimeter",
+        'Area' : "get_net_side_area",
     },
     'Qto_DuctSegmentBaseQuantities' : {
         'Length' : None,
@@ -506,10 +506,10 @@ mapper = {
         'GrossWeight' : None,
     },
     'Qto_WindowBaseQuantities' : {
-        'Width' : None,
-        'Height' : None,
-        'Perimeter' : None,
-        'Area' : None,
+        'Width' : { "function_name" : "get_length", "args" : ", main_axis = 'x'"},
+        'Height' : "get_height",
+        'Perimeter' : "get_rectangular_perimeter",
+        'Area' : "get_net_side_area",
     },
     'Qto_SanitaryTerminalBaseQuantities' : {
         'GrossWeight' : None,
diff --git a/src/blenderbim/blenderbim/bim/module/pset/notes_about_mapped_calculated_quantities.txt b/src/blenderbim/blenderbim/bim/module/pset/notes_about_mapped_calculated_quantities.txt
index d6a7e89ada..07c078bb13 100644
--- a/src/blenderbim/blenderbim/bim/module/pset/notes_about_mapped_calculated_quantities.txt
+++ b/src/blenderbim/blenderbim/bim/module/pset/notes_about_mapped_calculated_quantities.txt
@@ -8,6 +8,7 @@ This is in order to follow the native IFC approach.
 
 WALLS 
 Walls quantities are calculated with the convention that the object main axis is the 'x'. 
+Also openings inside a wall have to main axis 'x'
 
 SLAB THICKNESS
 The slab thickness is defined as Width, following the IFC definition
@@ -17,6 +18,9 @@ LATERAL AREA
 All lateral areas are counted, so for example also the inside surfaces.
 It shouldn't be like that so we should find a method to only external lateral area.
 
+DOORS AND WINDOWS
+Doors and Windows have to have the main axis along 'x' and the height is measured along 'z' axis
+
 
 
 
diff --git a/src/blenderbim/blenderbim/bim/module/pset/qto_calculator.py b/src/blenderbim/blenderbim/bim/module/pset/qto_calculator.py
index 2e61d74001..884272dba1 100644
--- a/src/blenderbim/blenderbim/bim/module/pset/qto_calculator.py
+++ b/src/blenderbim/blenderbim/bim/module/pset/qto_calculator.py
@@ -161,6 +161,11 @@ class QtoCalculator:
         self.delete_obj(gross_obj)
         return gross_perimeter
 
+    def get_rectangular_perimeter(self, obj):
+        length = self.get_length(obj, main_axis='x')
+        height = self.get_height(obj)
+        return (length+height)*2
+
     def get_lowest_polygons(self, o):
         lowest_polygons = []
         lowest_z = None
@@ -408,7 +413,7 @@ class QtoCalculator:
                 bl_OBB_opening_object = self.get_OBB_object(bl_opening_obj)
                 opening_area = self.get_lateral_area(
                     #self.get_OBB_object(bl_opening_obj), angle_z1=angle_z1, angle_z2=angle_z2, exclude_end_areas=True
-                    bl_OBB_opening_object, angle_z1=angle_z1, angle_z2=angle_z2, exclude_end_areas=True,
+                    bl_OBB_opening_object, angle_z1=angle_z1, angle_z2=angle_z2, exclude_end_areas=True, main_axis = 'x',
                 )
                 if opening_area >= min_area:
                     total_opening_area += opening_area