Ranch Renovation

Green Building Approaches

• The interior of the foundation walls was insulated to R-20 with 2lb closed-cell foam, with a new 2×4 framed wall spaced 1” away from the foundation wall to limit thermal bridging. The basement floor was insulated with 2” of expanded polystyrene foam board with an R-value of 8, followed by two layers of plywood.
• After stripping away the old siding, 2” thick polyisocyanurate foam boards were attached over the plywood sheathing, to eliminate thermal bridging. Then 3-1/2″ of 0.8lb spray foam was installed within the existing wall stud cavities to create an air-tight, R-28 exterior wall assembly with minimal thermal bridging (heat loss through the framing).
• In areas with a cathedral ceiling, the new 2×12 attic rafters were strapped with 2×3’s (to eliminate thermal bridging) and then 13” of 0.8lb spray foam was installed for a total R-value of 58. In areas where there is an attic above, the attic floor was first air-sealed with a thin layer of 2lb spray foam and then was covered by 16” of cellulose for a total R-value of 56.
• New Energy Star rated windows completed the envelope updates to this home.  These aluminum-clad wood windows feature dual glazing, argon gas fill, and a low-e coating.
• Light tubes were added to the main floor hallway, which was dark and windowless. The change was remarkable.
• The house is heated and cooled by a two-stage, forced-air geothermal system, which also contributes some hot water for domestic use. Hot-water is provided by a hybrid electric (air-source heat pumps) water heater. Ventilation is provided by an energy recovery ventilator.  Air filtration by a two-stage air cleaner.  All ducting was installed in the conditioned basement which is inside the thermal envelope.  All ducting is sheet metal and sealed with mastic.
• A 2.3kw solar photovoltaic system was installed on a south-facing roof area to generate electricity. It is estimated to generate 2,500Kwh/year.
• All toilets, shower valves, and faucets in the house were replaced with updated low-flow models.
• Pre-finished fiber cement siding was fastened to 1×3 firring strips which are screwed to the wall studs throught the polyiso foam board, leaving a rainscreen gap between the foam and the siding for drainage and durability. Low maintenance cellular PVC trim was used throughout for exterior trim.  All cut-off’s were returned to the manufacturer for recycling.
• New resource-efficient, character-grade, oak flooring was installed throughout the main floor of the house. The flooring was finished with a water-based finish.