Energy efficient design and construction can substantially reduce costs and pollution because nonrenewable energy sources of energy are expensive, potentially unstable, and create toxic wastes through their development and combustion. The long-term costs of energy to the homeowner are large, in dollars as well as in health and safety.
Reasons to Change
- The generation and use of energy is the single largest contributor to air pollution. It has also been linked to climate change. Source: Green Facts Each year the average house releases more than twice as much greenhouse gas as the typical car (more than 22,000 pounds of carbon dioxide). Source: Energy Star Home Advisor
- Air leakage from poorly sealed ductwork and building envelope can waste over 50% of a homes heating and cooling energy. Duct leakage (estimated at 30% of waste in some homes) can also create pressure imbalances in a home, endangering health and safety by drawing in outside air and causing backdrafting of combustion appliances. Air leakage also contributes to problems with moisture, noise, dust and entry of pollutants, insects, rodents and reduced fire safety. Source: Southface Institute
- The typical US family spends more than $1300 per year on energy costs. Ten to fifty percent of that energy is wasted and does not contribute to the comfort or convenience of the family.
Building energy efficient and renewable energy homes offers contractors advantages in the marketplace. The reputation of builders with satisfied customers passes among homeowners and potential buyers. Greater customer satisfaction will result from less noise, increased durability and comfort, reduced maintenance and operating costs, and the reduced reliance on pollution causing energy consumption. Energy-efficient homes and those with renewable energy systems qualify homeowners for resource efficient mortgages, and incentives for renewable energy technologies. The more skilled a builder is at conveying these advantages to home buyers, the more profitable the builder will be.
Energy efficiency is one of the most direct ways a person can realize the benefits of a green built home. By implementing energy efficient techniques, energy bill savings can reach 65%. Energy-efficiency can also improve the comfort, health, and safety of home occupants through improved indoor air quality, fire protection, noise levels, reduced maintenance, and increased durability.
P2 in Action
Whole-building design or a systems approach considers the interaction of all elements of the building site, building envelope, mechanical systems, and occupants to help achieve optimal energy performance. The key is to reduce the house load (energy use) using the best combination of:
- Conservation (insulation, efficient lighting and appliances, house orientation),
- Insolation (solar gain), and
- Thermal Storage (mass in walls and floors which helps keep the house a more constant temperature).
The emphasis on each should vary on a site-by-site basis.
Most energy-efficient homes have four basic elements in common:
- A well-constructed and tightly sealed thermal envelope with appropriate ventilation.
- Proper design and installation of heating and cooling systems (properly sized, high-efficiency, energy source, ventilation and ductwork).
- Energy-efficient doors, windows, and appliances.
- Home orientation and placement of building elements to maximize natural heating and cooling efficiency.
Source: Energy & Environmental Building Association
Specific ways to achieve energy efficiency through a systems approach include:
- Use of passive solar advantages on the building site (and appropriate overhangs),
- Efficient lighting,
- Water conservation fixtures and appropriate placement of water heating equipment,
- Design for appropriate insulation levels and reduce labor costs with Optimum Value Engineering (OVE) framing techniques,
- Incorporation of wind, hydrothermal and/or active solar technologies,
- Landscaping (trees, bushes, earthberms provide shading, block a prevailing wind),
- Thermostat with automatic setback for night and work times,
- Increased insulation in exterior wall, ceiling, floors and foundation,
- Moisture control within the building envelope to control moisture buildup,
- Selection of energy efficient appliances,
- Dampers on all vents, fans and chimneys
- Use of appropriate colored materials and coatings on exterior or roof (i.e. light colored where summer cooling climates dominate).
Assistance with Energy Efficiency
Guidelines, standards and incentive programs abound for energy efficiency in residential construction. Here are some suggestions:
- Organizations working to promote alternative energy strive to provide tax incentives and guidance to help builders and consumers more effectively incorporate renewable energy and energy efficiency into their homes.
- Affordable housing and economic development advocates support legislative mandates and establish requirements to include energy efficiency and renewable energy into housing assisted by their programs.
- Utility companies provide audits and incentives for energy efficiency, as well as renewable energy technology development.
- Certification and ratings programs create partnerships between builders and federal, state, local and nonprofit organizations to enhance communities and marketability one home at a time.
- Energy efficient construction may also qualify consumers for higher than normal debt-to-income ratio when calculating loan potentials, enlarging the market of potential home-buyers.
One rating program that deserves special mention is the Energy Star home labeling program. Energy Star standards are nationally recognized and commonly adopted as criteria for other incentive programs. This program of the Environmental Protection Agency requires homes to achieve 30 percent reductions in energy over the Model Energy Code and obtain a third party verification. Energy Star for New Homes Improvements to Existing Homes
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