Category THE ENERGY-SMART HOUSETHE

As home-energy audits become a more important part of building and owning a home, more and more auditors are enter­ing the field. Free audits are available from local utility companies, but this avenue has its pros and cons (see the sidebar on the facing page). Independent auditors tend to offer various packages that can be tailored to your home’s needs and your goals. Look for
an auditor who has been certified by CMC Energy Services, Building Performance Insti­tute® (BPI; www. bpi. org), or RESNET.

Although they don’t provide diagnostic testing of a home, CMC Energy Services auditors are screened and complete energy – inspector training. CMC-trained auditors pay $300 and spend two classroom days learning about energy fundamentals; they also receive instruction in how to use the company’s proprietary reporting software. Online refresher courses keep inspectors up to date. CMC maintains a searchable data­base so that you can find an inspector in your area.

BPI in Malta, N. Y., trains auditors to use diagnostic-testing equipment. To get BPI accreditation, an auditor goes through "a rigorous, credible, and defensible written – and field-examination process administered to individuals by BPI or its affiliates," according to BPI’s website. BPI affiliates, such as the Metropolitan Energy Center in Kansas City, Mo., are trained to give exams to prospective auditors. Then BPI awards certification to those auditors who pass the tests.

According to Dustin Jensen, associate executive director at Metropolitan Energy Center, a 40-hour auditor-training class costs $1,000, and the examination costs about $500, if there is no government subsidy
involved, which there often is. Affiliates are allowed to set their own prices for training, so they vary across the country. A searchable database of all BPI-certified professionals is maintained on the Building Performance Institute’s website.

RESNET has a similar teacher-mentor system. RESNET trains providers, who then train raters, who are the folks that do the audits. Certification requires a week of class­room time, and the cost varies from $1,200 to $1,500, depending on the provider. A list of providers and raters is available on the RESNET website.

The Department of Energy’s Energy Star program is not involved directly in the certi­fication of auditors, but Energy Star endorses both RESNET and BPI auditors in two sepa­rate programs. In the first program, Energy Star Qualified New Homes, houses must score at least an 85 on RESNET’s HERS-index rating. The second program, Home Perfor­mance with Energy Star, currently has locally sponsored programs in 28 states that help homeowners to improve a home’s energy ef­ficiency cost-effectively. The contractors that participate in the program are BPI-certified and are listed at www. energystar. gov.

Regardless of certifications, ask any audi­tor you might hire for a list of customers that you can contact to find out if they were satisfied with the auditor’s work.

There are a number of reasons to have a new home audited as well, not the least of which is to ensure that the building envelope and mechanical systems are performing as they were designed to perform. The Residential Energy Services Network (RESNET®; www. natresnet. org), a not-for-profit member­ship corporation, has developed an index called the home-energy rating system, or HERS, that both predicts and confirms a new home’s energy performance. The HERS index can be used to evaluate a home’s plans and specifications before it is built, then as­sign it a number from 0 to 100. A house that scores a 0 is said to be "net zero," meaning it produces as much energy as it uses over the

A duct blaster is not quackery. similar to a blower door, a duct blaster is a calibrated fan. It is used on buildings with forced-air heat or cen­tral air-conditioning. Leaking ducts can decrease the overall efficiency of your heating and cooling system by as much as 20%.

course of a year. A home that scores 100 is built to the energy specs of the 2006 International Residential Code® (IRC). Once the house is completed, it is tested by a RESNET auditor using scientific testing equipment to ensure the as-built house conforms to the as-planned HERS rating.

The reasons to get a verified new-house HERS rating are fourfold. Not only can a HERS-index rating help homeowners to qualify for an energy-efficient mortgage, but it also assures them that building efficien­cies have been verified by an independent third party. The HERS rating is also an excel­lent marketing tool, and it helps builders to qualify in the Energy Star® program.

■ BY JEFFERSON KOLLE

n the bill from her gas company, Leslie MacKensie of Minneapolis learned that she could have a free energy audit performed on her house, so she made an appointment. After assessing the 1915 bungalow, the audi­tors showed her air leaks and other problems that resulted in a monthly bill of $110. The auditors left her with weatherstripping and foam-insulation pads to install, along with a list of other needed improvements.

Chipping away at the list has had dramat­ic results. Even after she expanded her home with a small addition, her current gas bill averages only $80 a month. "Almost as im­portant," she says, "is that now our home is really comfortable to live in all year round."

Home-energy auditing—the process of diagnosing and recommending improve­ments to reduce a house’s energy consump – tion—is not a new idea, but the reasons to get an audit are more pressing as concerns about costs, comfort, personal health, and the environment loom large.

Along with free or reduced-cost audits offered by utility companies, an increasing number of private companies perform
audits. And while an old leaky house might be the obvious choice for an energy-waste diagnosis, new houses can benefit, too. The results can be an excellent marketing tool for builders and can help homebuyers qualify for an energy-efficient mortgage, which uses energy-cost savings to lower debt-to-income ratios.

The most important thing to note about energy audits, however, is that they don’t save money or energy. Implementing the recommended improvements is how the savings happen.

There Are Two Types of Audits

Energy audits vary in complexity from an unscientific but learned assessment to one that uses an assortment of diagnostic equip­ment to measure the performance of a house and its systems. The unscientific assessment typically consists of a thorough two- to three-hour walk-through, during which the auditor makes a visual inspection; takes pho­tographs; and records information about the

size of the building and specifics about the assumed efficiencies of the insulation, the appliances, and the HVAC (heating, ventila­tion, and air-conditioning) system. (For in­stance, he might know how fiberglass batts should be performing but can’t tell if they were installed properly.)

The scientific approach, which takes four to six hours to complete, uses diagnostic equipment to record and quantify a home’s energy shortcomings. The auditor completes a walk-through of the house, but he doesn’t stop there.

The first step is often a blower-door test. After closing windows, exterior doors, and often flues, the auditor turns on a calibrated fan mounted in an airtight frame temporar­ily set in an exterior door (see the photo on p. 5). The fan reduces air pressure inside the building, pulling air in through all the holes in the building envelope. Depending on the blower door’s supporting software, the audi­tor quantifies the number of air changes the house goes through in an hour (expressed as ACH) as well as the combined size of all the air leaks. In an old house, those leaks can
easily equate to leaving the bottom sash of a double-hung window open all year long.

To pinpoint where air infiltration is hap­pening, the auditor holds a smoke stick or smoke pen in front of doors, windows, or other suspect areas (see the inset photo on p. 5). The pen emits a chemical smoke that wafts away from the leak and toward the fan to identify air infiltration. The auditor makes a note of the location and later sug­gests how to seal the leak.

A blower-door test can find air leaks in heating and cooling ductwork that runs through unconditioned spaces, such as an attic or a crawlspace. But it can’t find leaks in ducts that run through the conditioned space, such as walls and floors. A tool made specifically for that job is a calibrated airflow-measurement device called a duct blaster. After turning off the blower door and taping over the floor, wall, and ceiling registers, the auditor connects the blaster to a central return in the system and measures its airtightness. Leaky ductwork can lead to substantial energy loss, which can be espe-

Making the improvements.

Sealing leaky windows and air ducts, and adding insula­tion are the most common improvements auditors sug­gest. Attics can be the largest culprits for air and energy loss.

dally costly when that loss is happening in an unconditioned space.

Perhaps the best qualitative scientific tool an inspector pulls out during a diagnostic audit is an infrared thermograph, a camera – style device that shows the relative tempera­tures of objects portrayed as a kaleidoscopic image (see the photos at right). The colors reveal heat loss or gain, which indicates if a wall or attic floor is insulated, for example, and how well that insulation is performing.

It also can identify moisture problems and leaky pipes behind the walls.

The auditor might also use a combustion analyzer and flue-gas monitor to measure the efficiency of boilers and furnaces (see the left photo on p. 8). Finally, he plugs in an electricity-usage monitor near appliances like the refrigerator to determine their efficiency.

Proponents of these diagnostic audits say that scientific measuring allows individual house components to be assessed as part of a whole system in which change to one part affects another. For instance, extensive air­sealing could make the building too tight and result in a furnace’s flue gases being sucked down a chimney and into the living space—something that might not be detected without testing. This system’s approach might also show that increasing insulation levels would allow a home to be heated by a smaller boiler. Test equipment can measure these kinds of occurrences, whereas a strictly visual inspection results only in an educated guess. The other main reason to use testing equipment is that retesting can determine the success of the recommended improvements.

Steve Luxton, regional manager for CMC Energy Services® (www. cmcenergy. com), disagrees with the need for scientific test­ing. Luxton’s company has trained more than 1,000 energy auditors, 90% of whom are working as home inspectors, the folks that mortgage companies require you to hire before they’ll lend you money. "These guys already know what to look for in a house,"

says Luxton. "[They] don’t need a fan to tell you where the leaks are."

His point is well taken; most experts agree that air infiltration is the No. 1 cause of en­ergy loss in any house. Most buildings have common air-infiltration areas that are easy to spot if you know where to look.

f there is one topic that has dominated the homebuilding field in recent years, it’s energy efficiency. But for all the headlines and airtime dedicated to the topic of trimming home-energy use, many of the discussions they generate don’t go any further than the admission that, yes, we need to work harder to save energy where we live. What we really need to talk about is how.

At Fine Homebuilding magazine, we focus not only on what good, responsible builders should do to construct or remodel homes that don’t waste energy, but also on how they do it. This book explains how you can, too.

In The Energy-Smart House, you’ll be able to follow these builders step-by-step through critical energy enhancements that include air-sealing, insulation upgrades, and window replacement, as well as choosing the best low-energy fixtures and appliances.

Today, the opportunities for reducing the energy requirements of the homes we live in—no matter how old they may be—are tremendous. The evolution in building products alone, from housewraps to LED lighting to high-performance windows, has equipped builders with a wide array of options to make homes more durable and healthier as well as less costly to live in and maintain. Ever-advancing technologies enable new mechanical systems to deliver heating, cooling, and hot water more effectively and at a lower cost. All the while, a greater understanding of building science enables knowledgeable builders to craft efficient, long-lasting dwellings regardless of the climate in which they build.

The fact is, true energy efficiency can only be achieved through a multifaceted approach that takes the whole house, its site, structure, and systems, into account.

A home is not made “energy efficient” by popping in a few new windows or loading up the attic with cellulose. Good builders know the path to energy efficiency is a multistep process, and that each improvement influences the steps that follow. And that the conscientious application of smart building techniques like the ones found here is the most reliable roadmap they can follow in their pursuit of an energy-smart home.

Debra Judge Silber, Managing editor, Fine Homebuilding magazine