This 9,500 square foot contemporary farmhouse in Leipers Fork, Tenn., is the retirement residence of the managing partner of the London office of an international public accounting firm and her husband, a college professor.
The owner also orchestrates her accounting firm’s environmental practice so it is no surprise the Leipers Fork home incorporated more than a dozen different green design practices during construction.
The couple worked with its general contractor, Pope Properties, Inc of Brentwood, Tenn., and Comfort Engineered Systems, Inc. of Nolensville, Tenn., to incorporate scores of energy savings technologies into the house.
For example, 9,000 square feet of Englert Series 2000 Series standing seam Dove Grey metal roof is the platform for 1,200 square feet of Uni-Solar photovoltaic laminate panels (from United Solar Ovonic) in three different roofing areas on the south side of the house, according to Stan Pope, owner of Pope Properties. The array delivers 3.24 Kilowatts an hour and is tied into the Tennessee Valley Authority’s electric grid through a specially installed bi-directional utility meter, which allows AC electricity to flow both into and out of the home. As a result the TVA pays the home-owners 15 cents a kilowatt-hour for all energy the house does not use and sends to the grid. Conversely, the homeowners pay an inexpensive eight cents a kilowatt-hour if they need to tap into the TVA grid.
Between the attic roof and the standing seam solar panels is a 1,800-square foot Dawn Solar geothermal solar system, says Pope. The Englert standing seam panels are a component of this solar collector, heating the metal roofing purlins. The purlins, in turn, hold and heat a water/glycol mixture circulated through a cross-linked polyethylene tubing that snakes back and forth through the purlins on the south side of the roof. Because the roofing material will radiate heat after it reaches a certain temperature, the system is self-regulating, preventing overheating and component damage when the system is inactive for extended periods of time.
The system helps heat the water in two home heating tanks, one of which provides 100 gallons for home heating and household hot water needs, while the second heating tank provides 50 gallons of water to the couple’s year round, outdoor pool. The couple also incorporated a 26,000 square foot in-ground geothermal heating system to provide additional heat for the house.
Two 10,000 gallon twin fiberglass rainwater harvesting systems are cosmetized by two observation towers that provide a view of the heavily wooded 13-acre property set in the heart of Tennessee’s prosperous Williamson County. The system provides up to 3,500 gallons of stored water per cycle for landscape watering and irrigation immediately around the house.
“This house is full of glass,” says Mike Warner, project manager for Pope Properties. “There are more square feet of glass than wall to capitalized on the many vistas from the structure.” Windows, featuring reflective argon gas, were sized and situated to capitalize naturally on heat and sunlight. Engineered lumber was used in all the joist systems. Existing trees were trimmed and enhanced and new trees were planted around the structure to enhance sunlight. R-38 insulation was used below the floorboards in crawl spaces that were also sealed to retain heat. Garage doors were insulated to save heat and low voltage lighting control systems were installed to save energy.
Perhaps most interesting of all is the home’s monitoring system which allows the couple to control the heating and lighting of the structure via the Internet from London.