During the first three months of data monitoring in early 2006, the home produced 35 percent more source energy than it consumed.

Credit: Pete Beverly

Affordable Housing Category
Arvada, Colorado

Habitat for Humanity of Metro Denver sponsored construction of a home in Arvada in September 2005.
It is a net-zero energy home that produces as much energy as it consumes over the course of a typical year.

	Use of Renewable Energy
	Project Team

As with all Habitat projects, the home was built with volunteers and sold to a low-income family with favorable terms on the mortgage. Most of the volunteers who built the home work at the National Renewable Energy Laboratory (NREL) in Golden. The home contains 1290 square feet of conditioned space and cost of less than $90 per square feet to build.

The home contains a number of energy efficiency features, including:

• Super-insulated building envelope: ceiling R-60; walls R-40; floor R-30.
• Fresh air ventilation with energy recovery.
• Energy Star® appliances.
• Compact fluorescent lamps in all lighting fixtures.

The home uses natural gas fired appliances for space heating, domestic water heating, and clothes drying. There are a couple of small baseboard electric heaters in the three bedrooms.

Use of Renewable Energy

The home was designed for simple construction by non-professional volunteers and for easy upkeep by the new owners. It contains a several renewable energy features, including:

Passive solar tempered design. Solar tempering takes advantage of larger windows on the south-facing elevation in order to increase solar gain in winter without energy storage. The south windows have overhanging shelves above them to shade the windows in the summer. The south windows have a high solar heat-gain coefficient (0.58); the north windows have a low solar heat gain coefficient (0.27). All windows have low-e coatings.

There are three solar water heating panels with a total collector area of 96 square feet on the roof (see photo). The panels connect to a 200-gallon water tank in the utility room that stores pre-heated water for domestic use.

A roof mounted solar power PV system rated at 4 kilowatts (kW). This system is sized to offset the energy use of natural gas appliances in order to achieve net-zero energy consumption.

CRES 2006 Vice President Doug Seiter awards a member of the project team the 2006 Colorado Renewable Energy in Buildings Award.

Project Team

The winning project team consisted of:

• Paul Norton, senior engineer at NREL; designer
• Habitat for Humanity of Metro Denver; project sponsor.
• PCD Engineering, mechanical design engineers
• The Midwest Research Institute and Battelle, managing partners for NREL, also sponsored the project.
• Dozens of NREL employees who volunteered their time to work on the project.