"On the Path" ZEH Demonstration - Bel Air, Maryland

Approaching a near zero energy home in the Mid-Atlantic Region

Bob Ward Companies of Edgewood, Maryland worked with the NAHB Research Center to build one of the first ultra energy-efficient production homes in the Mid-Atlantic region. Although the home does not boast 100 percent net-zero annual energy consumption, it is a significant step beyond the builder’s current ENERGY STAR® qualified home designs. It is also the first time Bob Ward Companies included renewable energy systems in a home. Combining state-of-the-art energy-efficiency features with solar thermal and photovoltaic technologies, the home is expected to perform about 50 percent better than a standard code-compliant home of similar size.

The 2,566 square foot home (3,724 with basement) is typical of many new homes built in the Baltimore-Washington area -- a two-story colonial with a full basement and attached garage. The only exterior features that distinguish it from its conventional counterparts are an array of photovoltaic panels and two solar thermal panels on the roof. The photovoltaic system will generate electricity that can either be used in the home directly or fed back to the utility during times when excess power is produced. The solar thermal system will preheat the domestic hot water and in a region like the Mid-Atlantic, is estimated to reduce energy purchased from the utility for water heating by at least 50 percent.

Other energy features of the home are less visible than the solar technologies, but integral to achieving a high-performance home. Reducing the energy required to provide the desired comfort and convenience is the first and foremost step in reaching net-zero energy consumption. Affordable and effective energy enhancements will be made throughout the entire home – building envelope, space conditioning systems, water heating, lighting, and appliances. The energy-efficiency features planned for the home include:

• A Superior Walls^TM foundation with an R-12.5 insulating value plus additional R-13 cavity insulation when the basement is finished.
• Continuous rigid insulation on the exterior walls adding an additional R-6.5 outside the wall framing.
• An increase in the wall cavity insulation from R-13 batt to R-15 blown insulation (which reduces infiltration losses in the wall).
• 14 inches (approximately R-49) of loose-fill fiberglass insulation in the attic.
• Low-e windows with a U-value of about 0.33 – an approximate 35% improvement over standard double-pane glazing.
• An extensive air sealing package to minimize air infiltration.
• Tankless water heater which will eliminate standby losses of a tank storage heater, resulting in a 10-20 percent reduction in energy use for water heating.
• ENERGY STAR® appliances.
• Energy-efficient lighting package to include fluorescent fixtures, compact fluorescent bulbs, and motion sensors on exterior lighting.
• SEER 19 Heat Pump

This project is sponsored by the Building America Program in partnership with:

See the energy features used in the Ultra-Efficient Home.