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.
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.
Slab edge assembly
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
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
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
Windows and Doors
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
Thermatru Smooth Star
Average window U-factor
Solar Heat Gain Coefficient
Visible Light Transmittance
100 sq ft
Space cooling - Manufacturer & Model
Space cooling - capacity
Space heating - Manufacturer & Model
Daikin (1) 4mxs32gvju 17.2 seer, (3) Daikin ctxs09hvju wall units