New Town Builders, now known as Thrive, built 26 units at the Row Homes at Perrin’s Row in Denver, Colorado, to the performance criteria of the U.S. Department of Energy Zero Energy Ready Home (ZERH) program.
Homeowners in the three-story row homes are projected to save $682 in annual energy costs thanks to the homes’ efficient construction and large expanses of south-facing roof ideally pitched to accommodate 3 kW of solar electric panels for each unit.
The Perrin’s Row homes are built to meet the specifications of the EPA’s Indoor airPlus Program, including low-VOC paints, low-formaldehyde wood products, sealed and cleaned air ducts, and a passive radon mitigation system to help provide a clean indoor air environment.
Water-saving EPA WaterSense-rated fixtures and a “smart” hot water recirculation loop reduce wasted water down the drain waiting for hot water inside. Drought-tolerant, climate-specific species and drip irrigation reduce irrigation water usage outside.
ENERGY STAR appliances and high-efficiency lighting provide energy and water savings.
Bottom plate-subfloor joints, corners, and wiring holes are all sealed with foam to improve the airtightness of the homes.
Advanced framing techniques include 2-by-6 studs spaced 24-inch on center with single top plates, two-stud open corners, right-sized headers, and open-framed interior-exterior wall intersections to reduce thermal bridging and provide more space for wall insulation. The framing lumber was locally harvested in the Colorado mountains from stands of trees that had been killed by beetles. New Town provided a market for this natural resource, which would otherwise have gone to waste.
The high-efficiency gas furnaces (92% efficient, 13 SEER) and supply and return ducts are all mastic sealed and are located within the conditioned space to minimize heat losses.
New Town Homes implemented a vigorous air-sealing program that included using a sprayer-applied air sealant at all top plate, bottom plate, and corner seams; installing closed-cell foam to insulate and air seal all rim joists; and foam sealing all penetrations. The homes also benefited from the air-sealing properties of the liquid-applied wall moisture control system.
An attic comfort perimeter uses raised heel trusses that allow for a full 14 inches (R-50) of blown fiberglass at the edges of the exterior walls. Baffles keep the insulation out of the soffit vents and encourage air flow under the roof deck of the vented attic. Hurricane straps tie the roof trusses to the wall for additional wind resistance.
The moisture control system uses a liquid-applied membrane that provides a seamless weather barrier over the walls, while peel-and-stick flashing is used for an extra layer of protection at the window sills.
After attaching netting to the 2-by-6 studs, workers fill the wall cavities with R-23 of blown fiberglass made from recycled bottles.
The home’s interior comfort system includes rigid metal ducting that is installed between the floor joists rather than in an unconditioned space such as an attic to minimize heat loss in winter and heat gain in summer.
The black coating on these walls is a moisture control system that uses liquid-applied asphalt. Additional flashing is installed around the high-efficiency, double-paned, argon gas-filled, vinyl-framed windows.
“My favorite part was knowing that I would have that extra barrier of safety and sound protection in the 'party' walls.”
“This is my first home and going into this experience, I wasn’t aware of all the benefits a DOE Zero Energy Ready certified home offers. The New Town team did a wonderful job explaining all the energy advantages my new home would offer. In my first walk-through with the construction superintendent, he made sure I understood how the house was framed. My favorite part was knowing that I would have that extra barrier of safety and sound protection in the 'party' walls. I don’t know the name of the 24-hour air circulation equipment, but it has been amazing. My previous apartment made my allergies terrible. Since moving in, they have gotten much better.”
– Homeowner
