Pioneer Valley Habitat for Humanity Net Zero Cottage
adding energy affordability to the paradigm
Walls and Roof
Double-stud, dense-packed cellulose, with some loose-fill in roof, and some rigid foam under slab. Air sealing primarily at sheathing, with backup at drywall.
Subslab assembly
4" XPS (donated by Dow)
Subslab R-value
22.0
Slab edge assembly
2" XPS between slab and stem wall
Slab edge R-value
11.0
Foundation wall assembly
slab on grade
Above grade wall assembly
double-stud dense packed cellulose, 11.5" frame to frame
Above grade wall R-value
37.5
Flat attic assembly
small portion of flat ceiling (1.5 story construction) with 24" loose fill cellulose
Flat attic R-value
81.6
Cathedral ceiling assembly
2/3 of ceiling sloped with dense-packed cellulose in truss depth, average 27" (model assumed R value 79 with thermal bridging of trusses, and at thinnest location for worst-case scenario, though could be up to 102.6 nominal)
Cathedral ceiling R-value
80.0
Roof Assembly
all insulation in depth of trusses
Windows and Doors
Window Assembly:
Paradigm casements low-e with argon, tuned with high-solar-gain glass on south windows
Door Assembly:
Therma-Tru Smooth Star S601LE
Average window U-factor
0.32
Solar Heat Gain Coefficient
0.28
Visible Light Transmittance
0.53
Door U-Factor
0.19
Door Area
20 sq ft
Mechanical Systems
Space cooling - Manufacturer & Model
same as above
Space heating - Manufacturer & Model
Fujitsu AOU24RXFZH, ASU12RLF1 and 2 ASU7RLF1
Domestic hot water - Manufacturer & Model
Geospring GEH80DFEJSR
Domestic hot water - capacity
80 gal
Domestic hot water - efficiency
3 kW
Ventilation - Manufacturer & Model
Lunos e2 (3 pairs)
Lighting Manufacturer and Model
Lighting Efficiency
Envelope
Air Changes per hour, ACH50
1.40 ACH50
Air Changes per hour, CFM50
Walls and Roof
Double-stud, dense-packed cellulose, with some loose-fill in roof, and some rigid foam under slab. Air sealing primarily at sheathing, with backup at drywall.
| Subslab assembly |
4" XPS (donated by Dow) |
|---|---|
| Subslab R-value | 22.0 |
| Slab edge assembly |
2" XPS between slab and stem wall |
| Slab edge R-value | 11.0 |
| Foundation wall assembly |
slab on grade |
| Above grade wall assembly |
double-stud dense packed cellulose, 11.5" frame to frame |
| Above grade wall R-value | 37.5 |
| Flat attic assembly |
small portion of flat ceiling (1.5 story construction) with 24" loose fill cellulose |
| Flat attic R-value | 81.6 |
| Cathedral ceiling assembly |
2/3 of ceiling sloped with dense-packed cellulose in truss depth, average 27" (model assumed R value 79 with thermal bridging of trusses, and at thinnest location for worst-case scenario, though could be up to 102.6 nominal) |
| Cathedral ceiling R-value | 80.0 |
| Roof Assembly |
all insulation in depth of trusses |
Windows and Doors
Window Assembly:
Paradigm casements low-e with argon, tuned with high-solar-gain glass on south windows
Door Assembly:
Therma-Tru Smooth Star S601LE
| Average window U-factor | 0.32 |
|---|---|
| Solar Heat Gain Coefficient | 0.28 |
| Visible Light Transmittance | 0.53 |
| Door U-Factor | 0.19 |
| Door Area | 20 sq ft |
Mechanical Systems
| Space cooling - Manufacturer & Model | same as above |
|---|---|
| Space heating - Manufacturer & Model | Fujitsu AOU24RXFZH, ASU12RLF1 and 2 ASU7RLF1 |
| Domestic hot water - Manufacturer & Model | Geospring GEH80DFEJSR |
| Domestic hot water - capacity | 80 gal |
| Domestic hot water - efficiency | 3 kW |
| Ventilation - Manufacturer & Model | Lunos e2 (3 pairs) |
| Lighting Manufacturer and Model | |
| Lighting Efficiency |
Envelope
| Air Changes per hour, ACH50 | 1.40 ACH50 |
|---|---|
| Air Changes per hour, CFM50 |