A high-performance car is built with a strong motor and a braking, steering and suspension system to handle the horsepower. Similarly, a high-performance home is designed and built so that the HVAC system is properly sized for the living space, fresh-air ventilation is used to counter air tightness and improve indoor air quality (IAQ) and the building envelope is designed to reduce the chance of mold growth.
While many attributes of a high-performance home are aimed at reducing energy costs, these homes also provide a superior living environment and make for a sound investment. Homeowners, builders and remodelers who set their sights on a high-performance home aren't just reducing greenhouse gases, promoting energy independence and creating jobs—they're creating more comfortable, durable and healthy homes.
Homebuilders and remodelers are in a win-win position thanks to government energy-efficiency incentives. By encouraging home buyers to invest in energy-efficient improvements, builders also position their companies as progressive, high-quality builders. Remodelers who can explain and help homeowners cash in on incentives become a valuable ally to their customers and can attract more business and larger projects. And by being able to communicate the benefits of a high-performance home to potential customers, builders and remodelers can gain a significant advantage over their local, traditionally minded competition.
Here are some of the technologies and energy-efficient improvements that builders and remodelers can encourage:
Building-envelope improvements. The building envelope is a continuous barrier built around, under and above the living space of a home. The "tighter," or more complete, the building envelope, the less likely water will be able to get into the walls and damage the structure or cause mold growth. Understanding how to properly install a successful building envelope requires training and attention to detail during construction, but the rewards to the occupant are many. A well-sealed building envelope can reduce the risk of pest invasion, mitigate radon and carbon monoxide and make a home more durable in wet, humid and cold climates.
The overall durability of a home, from structural integrity in the framing to the strength of the foundation, relies on a well designed and properly installed building envelope to prevent moisture intrusion.
Homes with attached garages require special attention to make sure car exhaust can't pass into the house. Likewise, gas-powered furnaces need to be properly vented and contained outside the living space. The building envelope is the primary barrier between these potentially poisonous fumes and the indoor air, which is why many rebate and loan programs specifically identify the building envelope as a critical part of home improvements.
Foam insulation. Builders and home buyers are generally correct when they think insulation is all about energy efficiency, but not all insulations are created equal. Spray-foam insulations can help increase structural integrity in hurricane-prone areas and provide significant R-value to areas where regular fiberglass insulation is difficult to install. Foam-board sheathing is also an excellent insulator and can be used outside the foundation walls of a basement or on the inside walls of a crawl space. Because foam board is also a vapor barrier, if it's installed snuggly with joints properly taped and caulked, it can work well on interior walls as well.
But insulation shouldn't be considered only for walls. Insulated ducts greatly reduce heat loss and can help reduce the size of the HVAC equipment needed for the home, which can save the customer money during construction or retrofit. Insulating hot-water lines helps with efficiency and also means hot water gets to the tap faster. Properly placed and installed insulation almost always cuts down on waste, improves comfort and qualifies the homeowner for significant energy-efficiency rebates.
Green building programs. Getting involved in a local or national green building program can give a homebuilder a considerable advantage in a competitive market. Building homes that achieve a third-party certification helps to verify the quality and performance of the home to the potential customer. And the U.S. Department of Energy offers the Builders Challenge program, which, like green building programs, supports participating builders with training and marketing opportunities and allow for a designation that identifies a builder as progressive.
In addition to these government programs, private initiatives such as the National Association of Homebuilders’ Green Building Program and the U.S. Green Building Council's LEED for Homes Program offer resources and benefits to builders and buyers.
Alternative HVAC systems. Traditional gas or electric furnaces, especially units that are Energy Star-rated, perform well, but new technologies have been introduced that offer higher levels of comfort and efficiency. Air-sourced heat pumps and geothermal heat pumps have become more common in the market, and most utility programs now offer loans or cash rebates for installing them.
Likewise, evaporative coolers that are Energy Star-rated can be ideal in warmer climates and, with proper windows, can match the comfort level of less efficient electric units. Biomass stoves may also be appropriate for heating homes or water in remote areas where natural gas is unavailable. Biomass stoves use wood pellets, corn or other organic materials as fuel, are highly efficient and consume renewable resources. Finally, on-demand water heaters, especially in the master bath, can add significant comfort while cutting down on water and energy waste. For remodelers installing soaking tubs, highlighting the benefits of a small on-demand water heater is an easy sell because the units capitalize on short runs, endless hot water and energy efficiency.
Advanced lighting strategies. Builders and remodelers can encourage customers to take advantage of natural lighting to decrease energy use and enhance the aesthetics of a home by installing skylights. Traditional and newer "tubular" skylights can be strategically installed in dark halls, closets and entryways to reduce the overall energy demand of the house while also bringing natural light into the living space.
The Energy Star program recognizes that skylights can keep homes cooler in the summer and warmer in the winter, which lowers energy bills and enhances overall comfort in the home. Along with natural lighting, replacing traditional incandescent bulbs with compact fluorescent (CFL) bulbs in all new-home construction is an easy sell. But beyond CFLs, LED lighting uses even less energy and can last for up to 50,000 hours. LED lights can be installed in any traditional light socket and, like CFLs, give off less heat than traditional bulbs, which can greatly reduce the cooling load in warmer climates.
Low-E windows. Window technology has improved rapidly in recent decades, and any home built before 1980 can greatly benefit from new windows. Today, windows are more energy efficient in terms of keeping conditioned air inside, which not only makes for lower utility bills but also adds to day-to-day comfort in the living space. One of the most significant improvements in window technology is the development of low-emissivity windows. Low-E glass is treated with a very fine layer of metal that blocks out certain ultraviolet rays from the sun and reflects a significant amount of solar radiation away from the home.
This filtering and reflecting process has a twofold effect. First, by reflecting solar radiation, less heat is allowed to enter the home, which creates a more comfortable living environment and lower utility bills. Second, by limiting the amount of ultraviolet radiation, low-E windows help protect carpets and furniture from fading due to exposure to direct sunlight. Low-E windows typically cost 10 percent to 15 percent more than regular windows, but they reduce energy loss by as much as 50 percent and extend the life of furnishings. Energy Star certifies windows that improve a home's energy efficiency, and window replacement often comes with significant financial incentives.
Duct sealing/air tightening. A poorly sealed duct system can render even highly efficient heating and cooling systems wasteful. The quality of the duct work can ultimately determine the efficiency of the heating and cooling system, but poorly sealed ducts pose other threats besides wasted energy and money. Ducts that are leaky or not properly sealed pose several serious risks to the home's occupants. For example, holes or poorly sealed joints in the duct system force conditioned (heated or cooled) air into places it should not be. Crawl spaces, walls and attics can become overpressurized when leaky supply ducts run through them, which forces conditioned air through the building envelope and outside of the home.
Likewise, if the return ducts aren’t properly sealed, they will suck in air from these same spaces. This can create IAQ issues by introducing dust, mold spores and other allergens that are pulled from unconditioned spaces. Another concern with leaky ducts is improperly vented gas-powered heating equipment. Leaky supply ducts can pull in harmful carbon monoxide and distribute the gas throughout the home. Finally, poorly sealed duct systems can significantly diminish the comfort of the home. Inconsistent ductwork will leave some areas of the home perpetually too hot or too cold and create an imbalance in air pressure from one room to another.
Home energy audits. No matter how well maintained, every home can use a home energy audit from time to time. An audit will help identify specific appliances that are energy inefficient and examine the use of the home, the lifestyle of the occupants and the overall health of the structure. During the course of a home energy audit, natural gas lines and electrical circuits will be inspected, and insulation levels will be measured and evaluated for effectiveness and consistency. Most audits include a blower-door test that gauges the airtightness of the home and measures how often indoor air is circulated or exchanged with fresh air from the outside.
After the audit, homeowners can expect to get a report that details energy use, significant health issues in the home and suggestions for lifestyle changes and energy-efficiency improvements. Home energy audits are often the first necessary step when applying for energy-efficiency loans or grants and are often offered free of charge by local utilities.
Solar water heaters. The main advantage of having solar water heaters is saving money, but they can also provide comfort and cleanliness when the power goes out. They don't need electricity to operate and can be installed to work simply off the municipal water pressure that normally flows to the home.
Programmable thermostats. Programmable thermostats allow occupants to manage the temperature of their home over the course of a week to maximize comfort while minimizing energy waste. Homes with programmable thermostats are more consistently comfortable than homes that require manually changing the thermostat based on activity and lifestyle. Additionally, programmable thermostats help extend the life of the HVAC equipment by allowing longer run times and a more consistent operation. This leads to monthly savings on energy bills, expanded equipment life and lower maintenance and replacement costs over the life of the house. Some utility companies offer rebates for the installation of programmable thermostats.
Cool roofs. Whether replacing an old and well-worn roof or choosing what materials to use to cover a new home, picking the right roof can significantly affect the durability, health and comfort of a home as well as improve energy efficiency.
The first goal of a roof is to protect the home by managing rain, snow and ice. But traditional dark-colored asphalt shingles absorb tremendous amounts of absorbed heat during summer days, making a home's cooling system have to work harder to maintain a comfortable temperature and leading to high energy bills and excessive wear and tear on equipment.
Another problem with dark roofs is a phenomenon called the urban heat island effect. In city or suburban neighborhoods, the collective heat trapped and radiated by dark-colored roofs can raise the relative local temperature by as much as five degrees during the day and keep it more than 20 degrees warmer at night than surrounding rural areas.
The good news is that "cool roofs" are available. Often white or another light color and made from various reflective materials, cool roofs reflect the solar radiation (heat) away from the house, making a home more comfortable during the warm months. And if entire communities switch to cool roofs, the urban heat island effect can be stopped, which further reduces energy demand in the area.