Cape Charles Residence, LEED Home

The LEED For Homes Rating System includes eight categories:
Innovation + Design Process 
Location + Linkages 
Sustainable Sites
Water Efficiency
Energy + Atmosphere
Materials + Resources
Indoor Environmental Quality
Awareness + Education

Objective
The unique site, at the tip of Virginia’s Eastern Shore, where the Chesapeake Bay meets the Atlantic Ocean, provides an opportunity to design with nature, capturing the expansive views, preserving the inherent natural setting, and creating a footprint that is as minimal as a footprint on a nearby beach.  The design challenge was to use as few resources—energy, water, and materials -- as absolutely necessary, and to have no discharge of stormwater or wastewater into the pristine waters, all this while protecting against coastal storms at an exposed location. 

Integrated design
The owner, architect, general contractor, landscape architect and mechanical contractor were brought together collaboratively, starting at the project’s inception, assuring integration of the design elements at all times of design and construction.

Architect: J. Harrison, Architect
Contractor: L. J. Kellam Construction
Landscape Architect: Siska Aurand
Structural: Sinclair Pratt Cameron
Mechanical: Trademark Mechanical Interiors: Cox, Kliewer & Company
LEED Provider: Earthcraft Virginia

Location 
The site was previously developed; the new house was built on top of the old footprint to minimize disturbance of the land. The existing driveway was reused.

Site layout
The house takes an organic shape in response to the beautifully irregular site.  The plan takes cues from the shape of the shoreline, taking care to maintain the waterfront setbacks.  The house is designed to align with both the sun and the view. 

Orientation & Shading
To take full advantage of the sun, most passive solar houses open up to the south.  This site has views in many directions but the most alluring is to the west.  This sets up a lively design challenge, a dialog between the sun and the view.
Here the roof bows down to the southern sun, offering photovoltaic panels to soak up the rays and provide electricity.  Below the roof, there are ample windows to the south to collect the winter sun.  The views are also opened to the west, with generous windows, but not without a serious strategy.  The late afternoon summer sun can create an overwhelming solar load on the air conditioning if not shaded. SunDial ™ seasonally selective shades are tilted, based on precise calculations for latitude and orientation, to protect from the summer sun while welcoming the winter sun.  These shades take the form of louvers in the vertical plane up high and a trellis in the horizontal plane to preserve the view at sight level.  The result is near 100% shading at the height of the summer sun, and full sunlight warming the house from the winter sun. 

Massing
The shape of the house allows for natural cross ventilation to take advantage of breezes in the warm seasons.  The roof shape responds to the climate by offering large overhangs for protection from both sun and rain.  The hip roof is inherently strong and stable in high winds. 
The house is all on one level in order to be easily accessible.  

Site
The vast majority of the site is left in a natural state.  Where the site was disturbed by construction, it has been replanted with native grasses that need no watering.  There are a few planting beds close to the house which are irrigated with a low water drip system supplied by rainwater collected in a cistern.  100% of the rain falling on the roof is collected in the cistern, reducing water use as well as reducing runoff to the bay.

Water Use
In addition to the use of rainwater for irrigation, water is also conserved inside the house.  Faucets and showers are water efficient, and all toilets are dual flush and/or low flow. 

Energy
The first and most important strategy for lowering energy use is to design the house to work with the local climate.  Orientation, massing, shading, natural ventilation, daylighting, insulation, and highly efficient windows are all crucial elements.  Only after all these factors are optimized should we resort to using energy to make the house comfortable.

• The walls are a thick sandwich of weather defense, spray foam seal and spray cellulose in a 6” cavity plus 1” rigid insulation outside the studs to provide a thermal break, topped with a rain screen gap to control moisture. 
  
• The conditioned envelope includes the attic so that the ducts can run in conditioned space, minimizing the issue of energy lost through leakage. The roof insulation is flash foam with 12” of cellulose.
  
• The house was tested with a blower door to reduce air infiltration.
  
• The mechanical equipment is highly energy efficient.  The ground source heat pump takes advantage of the stable temperature of water from the underground to heat and cool the house.  In the summer it uses water in the 50s instead of air in the 80s to cool the house, and the excess heat is reused to heat the domestic water for showers. 
  
• Radiant floors provide a level of comfort that allows the thermostat to be set at a lower temperature.
  
• Lighting is more than 80% energy efficient; either fluorescent, LED, or Energy Star certified
  
• A 5.7 kilowatt array of photovoltaic panels produce electricity from the sun. The panels are connected to the grid so they can feed energy into the grid when producing more than the home is using.

Materials
Every effort was made to use fewer resources, by using fewer materials overall, using recycled materials, using environmentally preferable products, or using local materials to minimize use of transportation resources.
Local products require less transportation, reducing both fuel use and emissions. An added benefit is supporting the local economy.

• Local lumber was used for exterior ad interior wall framing.
  
• Local gypboard was used for all interior drywall.
  
• Local concrete and aggregate was used for the foundation, floor, and patio.
  

Recycled materials use fewer new resources while diverting materials from the waste stream.

• The drywall is 95% recycled.
  
• The galvalume roofing is made from recycled steel.
  
• The cellulose insulation is made from shredded newspapers.
  
• Countertops are made from recycled materials such as recycled mirrors, aluminum, and shredded currency.
  

Rapidly renewable natural materials such as bamboo, cork, and linoleum are used for flooring.

Indoor Air Quality
The quality of the indoor environment was maintained by using paints with zero Volatile Organic Compounds (VOCs) and covering the ducts to keep out dust and debris during construction.

Ongoing maintenance of the home is made easier by providing covered entrances, walk-off areas, and dedicated shoe storage areas near the entrance.