Dripping Springs custom home
A retired couple planned carefully for their custom home. It had to be not so big. It had to be energy efficient and easy to maintain. It had to be situated on their property to take advantage of the Hill Country views and breezes. They came to us with well-thought-out goals, and we designed and built a house that would rate five stars if it were within the boundaries of Austin . (The Austin Energy Green Building program rates homes only within their service area.)
We built the house under the searing August sun, and it was plenty hot. But once we got the walls up - and even before we had installed the radiant-barrier metal roof -- the interior was cool because we built the house using Agriboard structurally insulated panels (SIP). Proper site orientation and natural ventilation let the constant southerly breezes blow through the house. The walls and underside of the roof decking are protected with sprayed-on foam insulation that expands to a depth of 4-1/2 inches -- it covers the roof rafters, wraps around the electrical wires, and creates a thermal envelope in the attic that won't let heat or cold penetrate from the outside.
True story: On one of those blast-furnace days in August, our designer (he's a hands-on kind of guy) was standing on a ladder and needed to remove a chunk of the foam insulation in order to install a flue for the Franklin wood stove. He cut out a chunk of foam and was surprised: On the top of the foam, next to the roof decking, it was warm to the touch from the summer sun, but the underside was perfectly cool. He tried to show this phenomenon to the homeowner, but by the time he could climb down the ladder with the piece of foam in his hand, the heat had already dissipated.
Here are some of the green and energy-efficient features in this house:
- Careful site orientation for sun and breeze.
- Shade from screened porch and overhanging eaves, and natural ventilation from careful window placement. Clerestory windows in the simple roof line allow extra ventilation on warm days.
- Agriboard structurally insulated paneling
- Radiant-barrier metal roof
- Double-pane, insulated metal frame, low-E windows
- Right-sized air conditioning system (based on a Manual J calculation) and programmable thermostat
- Exhaust fans for kitchen, laundry, bathrooms vent to outside (not the attic)
- Energy Star rated appliances
- Ceiling fans in every room
- Franklin wood stove
- Compact fluorescent lights
- Insulated metal exterior doors
- Hardiplank siding
- Polished concrete floors
- No-VOC paint
- Ceramic tile floors
- Custom cabinets made with no- or low-VOC adhesives
- Two 10,000-gallon tanks as part of the rainwater harvesting system
- Whole-house on-demand tankless water heater
- Xeriscaping, all natural landscaping, no turf grass
- Low-flow plumbing fixtures
- Recycled everthing where possible: Lumber longer than 2 feet -- reuse it. Concrete and stone rubble, metal scraps, corrogated, crates, pallets, paint buckets -- if we can't find a way to reuse it, it goes into our recycle center or is donated.