What is EcoBUILD?
EcoBUILD is a voluntary "green building" program created by Memphis Light, Gas and Water to stimulate energy and environmental awareness through the promotion and use of energy-efficient and environmentally-friendly technology, materials and techniques in new home construction. Many advances have occurred in the home building industry that can help minimize energy waste in your new home - and save you money on your MLGW bill - but you have to know what to look for and how to verify efficiency claims.
How does EcoBUILD work?
MLGW developed a voluntary set of EcoBUILD construction standards that exceed the newly adopted 2003 International Energy Conservation Code (IECC) and common building practices. By following these guidelines, participating builders can construct single-family and multi-family homes that use 30% less energy while providing greater occupant comfort and other environmental benefits
As of January 1, 2009, the State of Tennessee has adopted the 2003 IECC replacing the previous code adopted in 1992. In addition, a number of improvements have taken place in the manufacture of building materials to increase their energy efficiency and these materials are commonly available. However, most builders typically invest in upgrades homebuyers can see - such as flooring, countertops and cabinets - rather than focusing on hidden energy-saving opportunities that will reduce your monthly utility bill.
EcoBUILD offers the solution. A home built to EcoBUILD standards is designed to be 30% more energy efficient than typical residential construction in Shelby County. To accomplish this, participating builders follow EcoBUILD guidelines to meet key energy and environmental goals. Homes built to current EcoBUILD standards feature:
- Air conditioners rated at 14 SEER, not the minimum 13 SEER.
- Hard sheet metal ductwork that has been sealed with mastic compound or mastic-rated tape and performance tested by MLGW.
- Duct leakage cannot exceed 10%. (Builders are allowed to use minimal amounts of flexible ductwork, with individual runs not longer than 10 feet.)
- Low-e windows with superior energy ratings to minimize heat gain and reduce UV damage to floor coverings and furnishings.
- Wall cavity insulation of R-15 to reduce air movement (or R-13 walls with R-4 slab insulation).
- All wire and piping penetrations sealed with caulk or foam to block air flow.
- Radiant barrier to reduce heat gain through the roof, lowering attic temperatures.
- Recycled materials - such as roof decking, trim board or cellulose insulation to keep construction materials out of the landfills.
- Interior finishes - such as paints and stains with low volatile organic compounds (VOC), those "new smell" gases that can cause respiratory problems.
- Native or adapted plants to reduce landscape watering.
EcoBUILD homes are inspected twice by MLGW to ensure compliance with guidelines. An on-site inspection is performed before the drywall is installed to verify that air sealing, insulation, mechanical systems and other behind-the-wall measures are in place. A second inspection is performed at building completion. During this inspection, all EcoBUILD components are verified and the heating, ventilation and air conditioning (HVAC) system is tested for air tightness.
Benefits of EcoBUILD construction
Anyone can claim a home is "energy efficient," but EcoBUILD proves it through inspections and performance testing of every house.
Analysis of actual electricity and natural gas consumption for 54 EcoBUILD-certified homes indicates that annual energy use is substantially lower than anticipated with 34% savings in electric use and 56% in natural gas. These savings were determined based on average consumption per square foot, comparing the average EcoBUILD home to a modeled 1,500-square-foot home built to local codes and typical practices. The results are in - EcoBUILD homeowners are paying MLGW less each month, without sacrificing comfort!
How can I build or buy an EcoBUILD home?
EcoBUILD can be adopted by any builder, for any floorplan - as long as the property is within Shelby County, MLGW's service territory. You must apply for EcoBUILD participation prior to start of construction.
The majority of EcoBUILD-certified homes are located in Uptown, a redevelopment zone north of St. Jude Children's Research Hospital. When completed, Uptown will contain approximately 400 EcoBUILD-certified single-family homes, making it one of the largest "green communities" in the nation. Additional speculative and custom-built homes have been constructed elsewhere within Shelby County.
Participating Builders in EcoBUILD.
At this point, no builder has adopted EcoBUILD for all homes, so our participating builders may have certified one home or dozens under EcoBUILD. Whether or not the builder has participated in EcoBUILD previously, you can include EcoBUILD certification in the sales contract if you are contracting with the builder to construct a new home. This is a simple, effective way to ensure your new home is energy-efficient and comfortable.
If you're looking to buy a completed home, ask for evidence of energy efficiency. If it's an EcoBUILD-certified home, the builder will have documentation from MLGW, including a Homeowner's Manual that discusses all the unique green features of that particular home. If the home was not built using the EcoBUILD standards, but the builder promotes it as "energy efficient," ask for specifics such as:
- Air conditioner SEER rating (higher is better; the minimum rating for air conditioners is between 10 and 13 SEER, based on date of construction).
- Window ratings (double-pane, low-e, with a U-factor below .40 are better).
- Insulation levels (R-15 or higher in wall cavities, R-30 or higher in attics).
- Programmable thermostats.
- Fluorescent lighting (tubes or compact fluorescent bulbs).
Can EcoBUILD reduce my home's "carbon footprint?"
Yes. Since homes built to EcoBUILD standards use less energy than typical homes, there are environmental benefits from avoided emissions associated with electric generation.
MLGW has calculated the level of reduced emissions for EcoBUILD homes, based on the average annual household electric use per square foot. A typical home, based on energy modeling, would use 10.37 kWh of electricity per square foot, per year. The average EcoBUILD home uses 6.87 kWh, a reduction of 3.5 kWh per square foot per year. Multiply the 3.5 kWh savings by the size of the EcoBUILD home to see the electricity savings, also called avoided generation. For example, a 1,500-square-foot EcoBUILD home uses 5,250 fewer kilowatt hours of electricity per year. EPA's Power Profiler website estimates that using 5,250 fewer kilowatt hours eliminates the annual release of 7,855 pounds of carbon dioxide (CO2), 51 pounds of nitrogen oxides (NOx) and 20 pounds of sulfur dioxide (SO2) from regional power plants.
Can EcoBUILD be used for an existing home?
Unfortunately, no. Most of EcoBUILD's benefits are achieved from special attention given to air sealing behind the walls, higher wall insulation levels and duct sealing (including placement and tightness of air returns), in addition to properly sized and more efficient HVAC units and low-e windows. These are areas that cannot be accessed or improved easily in an existing home.
However, there are many things homeowners can do to improve the energy efficiency of an existing home.
- If you are planning to replace appliances or equipment, MLGW's Energy Saving Calculators are a great way to determine the long-term savings from buying more efficient models.
- In addition, you can read more about home improvements, new technologies and other topics at our Energy Smart Library.
By becoming more knowlegable about how energy is consumed in your home, you can prioritize improvement projects that will lower utility bills and improve comfort in your existing home.