Truro Beach House

A sustainable modern beach house in the dunes.

A client came to ZeroEnergy Design with an interesting proposition. They wanted to commission the design of an environmentally sensible beach home on Cape Cod. The trick was that they had some unusual space requirements, a narrow lot on an environmentally sensitive site, and a magnificent west-facing view.

THE CLIENT. A professional couple, each in different medical fields, have a large family including grown children and grandchildren. They normally reside in downtown Boston, but plan to spend their summers and weekends on the Cape. While their Boston residence accommodates some of their children, their new beach home will be the only place that will accommodate all seven of them, including their significant others and the grandchildren, thus dictating the need for an extensive number of bedrooms. The entire family will gather over the summer and on holidays, while the couple will use the home by themselves during weekends throughout the year.

CREATIVE PROGRAMMING. Planning for the extreme variation in occupancy was an issue the designers dealt with from the start. The home is split into a ˜Living Bar' and a ˜Sleeping Bar.' The Sleeping Bar is the expansion module with numerous bedrooms & bathrooms to accommodate the entire family. The Living Bar includes the living and dining areas, as well as a secondary master bedroom – all that the couple needs when the children are away. This programmatic zoning allows the Sleeping Bar to be shut down during the majority of the year to decrease energy use.

PERFORMANCE CHALLENGE. The site has a spectacular west-facing view of the water and sunset. The area of west-facing orientation of the glazing used to capture this view certainly isn't ideal for energy performance. The narrow lot size, combined with the client's square footage requirements and the obvious desire to be able to take in the view from the primary living space made the un-ideal orientation of the glazing unavoidable. The rest of the building envelope certainly offsets the luxury view. The contractor built the double stud framing which allows a continuous layer of foam insulation (uninterrupted by studs). The geothermal system, coupled with a radiant heating system, will supply all of the heating and cooling for the year. Energy efficient appliances, water heaters, and energy efficient fixtures complete the package. The client also decided to minimize the home's reliance of fossil fuels, using propane is only for cooking and an ambient fireplace.

SOLAR WITH BACKUP. The roof sports a large solar electric array to offset energy usage through the use of net metering. A battery back-up and energy management system stores electricity from the solar array to ensure the basic functions of the home through blackouts without the use of a gas-powered generator. The combination of the energy efficient building envelope and systems with the solar array allows the home to produce nearly as much energy as it uses over the course of a year.

SELECTIONS. Choices were also made to promote healthy indoor air quality. Flooring was limited to slate, bamboo, and polished concrete, while omitting any carpeting that might capture dust, mites, mold, or moisture. The rapidly renewable bamboo flooring is bound with nontoxic glues. The insulation in interior walls and floor, used for sound insulation and to improve the performance of the radiant heating system, is formaldehyde-free. An air exchange and energy recovery system will provide clean fresh air throughout the year.

Finally, the exterior finishes will allow the home to turn a traditional Cape Cod grey and blend into the dunes. The site is vegetated with indigenous plants that prevent erosion and won't require irrigation.

More: ZeroEnergy.com/tru...