Winner - Environmental Design + Construction Magazine Excellence in Design Award in Single-Family Residential category
The McCullough residence is a green healthy home that was commissioned by an EPA scientist for her private home. The objective was to create a healthy home with optimum energy efficiencies that was affordable and aesthetically pleasing while minimizing potential impacts to the environment. The result is a 2200 square foot home that is efficient, spacious, low cost to operate, attractive and comfortable to live in. This home was recently featured on NBC News' segment called "Go Green Extreme" and set new records in North Carolina with the highest Gold rating for Healthy Built Homes.
The building envelope is constructed of prefabricated panels called Agripanels. They are factory built, pre-engineered panels where oriented strand board (OSB) sandwiches a compressed wheatstraw that is treated with safe and effective Borax for mold and pest protection. The results are exterior walls with an R value of 25. 4 with virtually no thermal short circuits or energy wasting from air infiltration. In addition, a natural hydraulic lime stucco was applied allowing for natural breathing reducing mold, mildew and air quality issues. Unlike conventional cement stuccos, this lime stucco moves, allowing it to "heal" itself should any cracks form. As it cures the lime stucco absorbs CO2, counter balancing the CO2 created during production, resulting in carbon neutral footprint. The roof is galvanized 5V metal with a 100 year life that is easily recyclable at the end of it functional use.
The other exterior green innovations include solar collectors for hot water supply and PV panels for solar electrical power generation. This solar solution is connected to the power grid allowing the energy produced to be sold to the power company at a premium and bought back at a discounted rate. This effectively reduces the payback for this system from 20 to only 7 years. The home's design and lot positioning were fine tuned to optimize these solar systems and leverage the benefits of a passive solar architecture. The living areas enjoy an open southern exposure while the North, East and West sides have minimal windows to reduce heat loss. Though all windows are wood with aluminum clad, the windows on those three sides are low-E and argon filled to optimize their insulation value and all windows have 2 foot overhangs; which is optimal for this latitude. All attic areas are conditioned for storage and to aid the efficiency of the mechanical system. They are insulated with Icynene insulation which provides outstanding r-value in a small amount of space while creating a protective barrier sealing against air leakage.
Inside, the first floor has concrete radiant floors with integrated color and soy-based sealer providing an efficient, low cost heating solution. Blown Cellulose insulation was used in between the floors to enable the upper floor to be sealed off from the lower floor when not in use. Recycled cabinets were used in the laundry and old windows were converted into cabinet doors in the pantry. The loft rails were made entirely from reclaimed metal scraps. The kitchen cabinets are a formaldehyde free plywood called 'Purebond' with a cherry veneer. Instead of glass in the cabinets and the living room pocket doors, a product called '3 form' is used. 3 Form is made from recycled soda bottles. In addition, the pocket doors were recycled from an old science lab at Duke University. The counter tops are stainless steel and the island is made of plyboo; bamboo that is set on the endgrain. It is harder than maple and more dimensionally stable than wood with a regrowth rate of only 3-5 years.
Other green materials used include interior doors made of compressed wheat with cherry veneer, bamboo stair treads and the upstairs flooring is Marmoleum; a linoleum made from 100% natural ingredients including linseed oil, cork, limestone, tree rosin and natural minerals. The plumbing fixtures are all low flow, the appliances are Energy Star rated and compact fluorescents are used throughout the home.
Achieving the objectives of this home owner were important as the owners want to be able to showcase the home to further promote living green. This 'green' home is a shining example of how healthy, environmentally friendly and energy efficiency can also be elegant, attractive, and comfortable.