Single Family Home

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Project Background

The original homeowners were inspired by their son to build sustainably. The goal was simple: to achieve an energy effective, resource efficient design that would sit lightly on the land and use a holistic design approach. In 2006, the homeowners hired an architect to design a four-bedroom home overlooking Narragansett Bay in Rhode Island. The 10,000 sq. ft. sloping site contained a 700 sq. ft. seasonal cabin that the homeowners had owned for fifteen years.

Sustainable, Modest & Durable

The house was designed to blend in with the architectural style of the neighborhood by marrying eco-friendly strategies with the local vernacular. The house exterior of cedar shingles with a standing seam metal roof is typical in New England. A durability plan was developed early in the design phase to ensure that the building envelope would resist water intrusion from the sloping coastal site and buffer the high winds and impact from debris characteristic of a 120 mph hurricane. From the onset, the LEED® rating system goal was Platinum. Construction began in 2007 and the home was completed in July of 2008. It is the first LEED-certified home in Rhode Island.

Strategies and Results

Principal strategies were to take advantage of passive solar energy and maximize the active solar energy potential. Passive strategies include properly sized overhangs and glazing appropriate for the latitude as well as interior spaces zoned for maximum daylight. Other advanced building techniques include a well-insulated envelope with a fully insulated basement slab, Insulated Concrete Forms (ICFs) and Structural Insulated Panels (SIPs). LED and fluorescent lighting fixtures as well as Energy Star appliances reduce energy demand. A “desuperheater” was added to the heat pump to preheat water and capture waste heat, thereby reducing the use of propane in the home. The heat recovery ventilation system was designed to maintain a minimum 60oF air flow tempered from outside, ensuring that humid outdoor air does not exceed a relative humidity of 60%. There are two instantaneous hot water heaters within 20 ft of all water fixtures. The refrigerant used in the ground source heat pump has no global warming or ozone depleting effect. The entire south-facing roof supports a 5.32 KW photovoltaic solar array used to power the house.

Water infiltration below the basement slab is controlled using 12 inches of crushed rock with two types of drainage systems and 4 inches of extruded polystyrene insulation below the basement slab continuous with the insulation of the ICFs. The uphill basement exterior and contiguous north and south walls – subject to significant up slope runoff – have two types of drainage planes and 4-inch perforated drain pipes in addition to footing drains. Backfill is sand below grade.

Aboveground moisture mitigation includes the application of Home Slicker house wrap to the exterior of the SIPs with a drainage plane between the felt and cedar shingles. Roof SIPs are covered with #30 felt and a 50-year standing seam metal roof with a high reflectivity finish; gutters and leaders are zinc. Rainwater is collected from the roof for irrigation, which also mitigates wastewater runoff into the bay. Greywater is treated with an advanced sewage treatment system required by local code.

Recycled materials were used throughout the house. The flooring is reclaimed heart pine manufactured in southern New Hampshire out of timbers removed from mill buildings in upstate New York. The structural posts and beams concealed inside the ceilings and walls are micro laminated composite wood.

Download LEED Project Profile (PDF)