Revell Retrofit
a Two-Family Deep Energy Retrofit with National Grid
Walls and Roof
The 100+ year old framing was strong enough on the walls but not the roof, so we replaced the roof with thick framing for superinsulation and added 4" more insulation to the exterior of all the walls and roof. The siding needed replacing anyway, making an exterior approach easy. We were not up to the task of excavating around the foundation, so we had to move inside for the basement insulation.
Subslab assembly
Given the existing slab, we insulated above the slab. Dimple mat to allow movement of any water, taped. 2" rigid foam (XPS) insulation, taped. Click-together laminate flooring.
Subslab R-value
10.0
Slab edge assembly
n/a
Foundation wall assembly
We used foil-faced polyiso on the walls to provide a vapor barrier as well as air sealing and insulation. Two layers offset provided backup.
There were masonry nails in the brick foundation, and rather than risk destroying the brick (with hours of hard work) we decided to use thicker insulation on the first layer.
2" + 1" for a total of 3" foil-faced polyiso
Foundation wall R-value
20.0
Above grade wall assembly
The house is balloon framed with actual 2"x4" lumber. Our favorite insulation, dense packed cellulose, was not enough to superinsulate. We used it in the existing framing, and then added 2, 2" foil-faced polyiso layers staggered on the exterior. Furring strips held the siding away for airflow.
Above grade wall R-value
41.0
Flat attic assembly
The third floor is tucked up under the roof, with only a short kneewall above the floor deck. A small amount of flat ceiling has a minimum of 24" of loose cellulose, but otherwise the assembly is cathedral.
Cathedral ceiling assembly
The existing roof was very bowed, in one case slumping 4" just from one end of the dormer to the other. It was not thick enough for superinsulation either, and sistering deeper framing was not a preferred approach by our builders. So we replaced the framing with 2x10s, filled with dense-packed cellulose, and added 2 layers of 2" foil-faced polyiso on top.
Cathedral ceiling R-value
60.0
Roof Assembly
see above
Roof R-value
60.0
Windows and Doors
Window Assembly:
vinyl, Paradigm, mostly double-hung, a few casement, two awning and 3 fixed in basement, all triple glazed, low-e (surfaces 2 and 5) with argon
8321 Premium Double Hung foamed frame
Door Assembly:
Thermatru Smooth Star
Average window U-factor
0.20
Solar Heat Gain Coefficient
0.25
Visible Light Transmittance
0.42
Door U-Factor
0.20
Door Area
100 sq ft
Mechanical Systems
Space cooling - Manufacturer & Model
same
Space cooling - capacity
9 kW
Space heating - Manufacturer & Model
Daikin (1) 4mxs32gvju 17.2 seer, (3) Daikin ctxs09hvju wall units
Space heating - capacity
9 kW
Domestic hot water - Manufacturer & Model
GE Geospring GEH50DEEDSR
Domestic hot water - capacity
50 gal
Domestic hot water - efficiency
2 kW
Ventilation - Manufacturer & Model
Venmar Kubix 44112
Lighting Manufacturer and Model
Lighting Efficiency
Envelope
Air Changes per hour, ACH50
0.65 ACH50
Air Changes per hour, CFM50
476.00
Walls and Roof
The 100+ year old framing was strong enough on the walls but not the roof, so we replaced the roof with thick framing for superinsulation and added 4" more insulation to the exterior of all the walls and roof. The siding needed replacing anyway, making an exterior approach easy. We were not up to the task of excavating around the foundation, so we had to move inside for the basement insulation.
| Subslab assembly |
Given the existing slab, we insulated above the slab. Dimple mat to allow movement of any water, taped. 2" rigid foam (XPS) insulation, taped. Click-together laminate flooring. |
|---|---|
| Subslab R-value | 10.0 |
| Slab edge assembly |
n/a |
| Foundation wall assembly |
We used foil-faced polyiso on the walls to provide a vapor barrier as well as air sealing and insulation. Two layers offset provided backup. |
| Foundation wall R-value | 20.0 |
| Above grade wall assembly |
The house is balloon framed with actual 2"x4" lumber. Our favorite insulation, dense packed cellulose, was not enough to superinsulate. We used it in the existing framing, and then added 2, 2" foil-faced polyiso layers staggered on the exterior. Furring strips held the siding away for airflow. |
| Above grade wall R-value | 41.0 |
| Flat attic assembly |
The third floor is tucked up under the roof, with only a short kneewall above the floor deck. A small amount of flat ceiling has a minimum of 24" of loose cellulose, but otherwise the assembly is cathedral. |
| Cathedral ceiling assembly |
The existing roof was very bowed, in one case slumping 4" just from one end of the dormer to the other. It was not thick enough for superinsulation either, and sistering deeper framing was not a preferred approach by our builders. So we replaced the framing with 2x10s, filled with dense-packed cellulose, and added 2 layers of 2" foil-faced polyiso on top. |
| Cathedral ceiling R-value | 60.0 |
| Roof Assembly |
see above |
| Roof R-value | 60.0 |
Windows and Doors
Window Assembly:
vinyl, Paradigm, mostly double-hung, a few casement, two awning and 3 fixed in basement, all triple glazed, low-e (surfaces 2 and 5) with argon
8321 Premium Double Hung foamed frame
Door Assembly:
Thermatru Smooth Star
| Average window U-factor | 0.20 |
|---|---|
| Solar Heat Gain Coefficient | 0.25 |
| Visible Light Transmittance | 0.42 |
| Door U-Factor | 0.20 |
| Door Area | 100 sq ft |
Mechanical Systems
| Space cooling - Manufacturer & Model | same |
|---|---|
| Space cooling - capacity | 9 kW |
| Space heating - Manufacturer & Model | Daikin (1) 4mxs32gvju 17.2 seer, (3) Daikin ctxs09hvju wall units |
| Space heating - capacity | 9 kW |
| Domestic hot water - Manufacturer & Model | GE Geospring GEH50DEEDSR |
| Domestic hot water - capacity | 50 gal |
| Domestic hot water - efficiency | 2 kW |
| Ventilation - Manufacturer & Model | Venmar Kubix 44112 |
| Lighting Manufacturer and Model | |
| Lighting Efficiency |
Envelope
| Air Changes per hour, ACH50 | 0.65 ACH50 |
|---|---|
| Air Changes per hour, CFM50 | 476.00 |