Energy Efficient Houses at Nyland

Home Energy Magazine Online
July/August 1997
by Nancy Hurrelbrinck

Completed in 1993, the Nyland Community has 42 homes on about 6 acres, with 20 acres of shared open space, a solar-heated greenhouse, a workshop, and a 6,000 ft2 common house. The open space and common facilities are owned and managed by a homeowners' association. Because residents wanted their homes to be partially heated by solar radiation, the pedestrian streets run east/west, and the houses have a north/south orientation. This is unusual in developments on Colorado's Front Range, where most houses are built to capture the spectacular mountain views to the west without regard for overheating on summer afternoons.

Homes at Nyland have 2 x 6 optimum-framed walls insulated with wet-spray cellulose made mostly from recycled paper. Truss-joists were used in floors, and in roofs when cathedral ceilings ruled out truss roofs. The walls are R-24 and the ceilings R-42. Finished basement walls are insulated to R-13 and unfinished ones to R-5. To increase the whole-wall R-value, the insulation area was increased and lumber use reduced with optimum framing techniques, including 24-inch on-center framing and oriented strand board sheathing.

Most homes are clustered in groups of two or three under one roof, reducing the ratio of exterior wall area to interior air volume and decreasing the amount of structural lumber needed. Party walls have 2 inches of dead air space between insulated walls to decrease noise transmission. Similarly priced townhouses in the area have one 2 x 6 framed insulated wall separating adjoining houses.

All houses in the community have R-3 double-hung, double-pane, low-e windows rather than the R-2 thermal pane double-glazed windows typically found in similarly priced tract homes. The R-3 windows cost 20%­ more than typical windows, but community members saved money by forgoing a primed exterior surface. This also allowed the members to paint the windows themselves, using a variety of colors.

The homes also feature 90%-efficient direct-vent condensing gas furnaces, power vented water heaters, reduced-flow plumbing fixtures, setback thermostats, and compact fluorescent lights.

The common house has forced-air heating divided among four separately controlled zones using electronically controlled duct dampers on a 90%-efficient gas furnace. The house incorporates high clerestory windows at the center of the building, eliminating the need for electric lighting in most parts of the building during the day.

Wonderland has monitored the development's energy bills and compared them with average bills for Colorado homes of the same age and square footage. They have found that the Nyland homes use energy at only half the average rate. Data provided by the Public Service Company of Colorado (PSCO) indicate that Nyland homes use an average of 62% less natural gas and 33% less electricity than the average for Colorado homes built in 1988 and 1989.

David Lowell and Kimeri Brown's 1440 ft2, three-bedroom house is typical of homes at Nyland. It has a total of 111 ft2 of south-facing glazing, or about 8% of the floor area. Since the home is part of a cluster of three units and its west wall adjoins a neighbor's home, the occupants opted for 104 ft2 of glazing to the east, but only 34 ft2 to the north.

Wonderland compared the Lowell/ Brown home with a computer-generated base case tract home. The base case has the same design, but minimum efficiency measures. The base case had a heating load of 36,000 Btu/ft2 per year, while the Lowell/Brown home requires only 26,000 Btu/ft2 per year, due to higher R-values and tighter construction. The solar gain resulting from the sun-tempered design lowers the heating load another 25% to 19,500 Btu/ft2 per year. The natural gas bill for space heating (separate from hot water and cooking) would be $198 per year, or 46% less than the $365 bill for a typical tract house.

Nyland won $100,000 in grants from the Colorado State Office of Energy Conservation and the Environmental Protection Agency for its commitment to energy conservation. Of this amount, $40,000 was designated for energy improvements to homes, $20,000 for energy improvements to the common house, and $40,000 for indoor air quality improvements.