CRed - The Community Carbon Reduction Project at UNC-Chapel Hill

Houses and commercial spaces are responsible for up to a third of the carbon dioxide emissions in the U.K. It is recommended that the indicator of sustainability be the BREEAM (Building Research Establishment Environmental Assessment Method) EcoHomes assessment and certification system. BREEAM rates buildings on their degree of sustainability using a variety of measures of energy efficiency, water use, pollution potential, materials use, etc. A final score is based on a summation of points earned across all of these measures, with a final score from Good to Excellent. Specific goals should ensure that:

• All residential/commercial buildings receive a BREEAM EcoHomes rating of Very Good
• All residents attain the maximum points possible in the EcoHomes Energy Use sector, and as a result reduce energy use by no less than 50% below that associated with standard designs in the U.K.

All residences attain the maximum points possible in the EcoHomes Human Health sector.

The policies listed below constitute best management practices for sustainable housing that are both technologically feasible and economically viable. When incorporated into a home, these practices will increase the energy efficiency of that structure and obtain a rating of Very Good or higher according to the BREEAM assessment.

1. Reduce Air Infiltration: Air leakage accounts for 25% to 40% of the energy used for heating and cooling in a typical home. Many products available for air sealing including caulks, foams, gaskets, door sweeps and weather-stripping, can reduce energy use in heating and cooling by 25% or more.
2. Increase Efficient Air Ventilation: Typical ducts can be so leaky that more than 35% of heated or air-conditioned air is lost before it arrives in the intended room. Duct tape, which is commonly used, is an insufficient sealant; instead, UL listed tapes or duct mastic should be used to seal all joints and seams in the ductwork.
3. Install High Performance Windows: Heat gain and loss through windows accounts for up to 50% of a home's heating and cooling needs. The use of window technologies such as double or triple glazing and the application of low energy coatings can substantially decrease the transfer of heat and cold, reducing energy use for heating and cooling by as much as 15%.
4. Improve Insulation: The thermal resistance rating given to types and quantities of insulation is referred to as the R-Value. The higher the R-Value of a given material, the better its ability is to resist heat flow. The U-Value is the reciprocal of the R-Value, and is instead a measure of heat loss. R values of at least 20 in walls and 50 in attics should be used.
5. Install Energy Efficient Heating & Cooling Equipment: Since heating or cooling a home can account for over 50% of the home's total energy use, the efficiency of heating and cooling equipment must be maximized to the extent feasible.

Other policies include practices of value engineered framing, duct location, duct insulation, duct sizing and design, framing materials, window tightness, and energy efficient appliances. Please see the 2004 Final Report for a complete listing and description of best practices for energy efficiency in homes and commercial buildings.