Project Description
This chainsaw retrofit project, completed by Solar Homes Inc., focused on creating a super-insulated, energy-efficient home with dramatically improved airtightness. After cutting off the eaves, the home was wrapped in continuous air and thermal barriers. The team upgraded key systems throughout the house, including electrifying heating, cooling, and hot water, and upgrading the electrical system. The home’s energy use dropped from 141 GJ annually to just 55 GJ. With the installation of a solar system, it’s now just 33 GJ, a drop of over 76 per cent.
Before & After
General
|
|
Before |
After |
Building Condition
|
Before
Dated vinyl exterior, wood eaves, well maintained, but older. |
After
Modern and clean aesthetic. |
Comfort
|
Before
Drafty, noisy envelope. |
After
Improved air quality, comfortable temperature management. |
Envelope
|
|
Before |
After |
Ceiling/Attic Insulation
|
Before
Several inches of blown in insulation in attic. |
After
Eaves removed, air barrier wrapped over old roof deck, 18″ cavity added over existing roof deck and insulated with fibreglass batts |
Ceiling/Attic Insulation
|
Before
42.8 R |
After
57.4 R |
Foundation Insulation
|
Before
Typical 2×4, 16 inch centers, Fiberglass batts. |
After
Foundation perimeter hydrovacced to add R20 of rigid insulation. |
Foundation Insulation
|
Before
10 R |
After
28 R |
Wall Insulation
|
Before
Vinyl exterior, 2×4 wood frame, 16 inch centers, R12 Fiberglass batts, gyp rock interior finish. |
After
6″ Rockwool mineral wool added to assembly exterior with strapping and Hardie siding. |
Wall Insulation
|
Before
12 R |
After
29 R |
Windows and Doors
|
Before
Double pane vinyl windows. Insulated steel doors. |
After
Double pane vinyl windows with low E, Triple pane vinyl windows with Low E |
Air Changes per Hour
|
Before
4.4 ACH50 |
After
0.95 ACH50 |
Air Sealing
|
Before
Typical vapor barrier, door weather stripping. |
After
Continuous air and thermal barriers over original exterior sheathing of walls and roof. |
Mechanical & Electrical
|
|
Before |
After |
Heating
|
Before
Condensing natural gas furnace (92% AFUE), additional boiler system (80% AFUE) |
After
Daikin Skyair 2.5 ton heat pump, electric heat backup |
Cooling
|
Before
None |
After
Daikin Skyair 2.5 ton heat pump |
Hot Water
|
Before
AO Smith Air source heat pump hot water tank |
After
Retained the AO Smith Air source heat pump hot water tank |
Ventilation
|
Before
Bathroom fans. |
After
HRV |
Renewables
|
Before
Approximately 3kW Solar PV |
After
6.4 kW Solar PV |
Electrical Service
|
Before
100 Amps |
After
200 Amps |
Annual Energy Usage
|
|
Before |
After |
Light and Appliance Energy Consumption
|
Before
12.24 GJ |
After
11.55 GJ |
Other electrical consumption
|
Before
13.77 GJ |
After
13.75 GJ |
Space Cooling
|
Before
0 GJ |
After
2.2 GJ |
Space Heating
|
Before
122.4 GJ |
After
23.1 GJ |
Ventilation Energy Use
|
Before
0 GJ |
After
0.55 GJ |
Water Heating
|
Before
4.59 GJ |
After
3.85 GJ |
Total Net Consumption (with Renewables)
|
Before
141 GJ |
After
33 GJ |
Total Annual Consumption
|
Before
153 GJ |
After
55 GJ |
Annual Cooling Demand Intensity
|
Before
0 kWh/m2/a |
After
2.13 kWh/m2/a |
Annual Electricity Consumption
|
Before
8889 kWh |
After
15278 kWh |
Annual Heating Demand Intensity
|
Before
120.18 kWh/m2/a |
After
22.41 kWh/m2/a |
Annual Natural Gas Consumption
|
Before
121 GJ |
After
0 GJ |
Energy Use Intensity
|
Before
150.23 kWh/m2/a |
After
53.36 kWh/m2/a |
Carbon Emissions
|
|
Before |
After |
Annual Operational Carbon Emissions – Electricity
|
Before
2722.22 KgCO2e |
After
4491.67 KgCO2e |
Annual Operational Carbon Emissions – Natural Gas
|
Before
6364.66 KgCO2e |
After
0 KgCO2e |
