Comfort callbacks are both timely and cost consuming, so here’s what you can do to reduce them.
The single largest financial investment that consumers will make in their lifetime is their home and a wealth of research finds that homeowners want their abodes to be energy efficient and comfortable. Both comfort and energy efficiency rely heavily on the delivery of consistent, quality construction, yet despite builder efforts, that goal falls short at times, leading to problems with home comfort. What can builders do to reduce comfort callbacks?
Delivering a More Comfortable Home
Steve Easley is a veteran building science consultant who’s spent more than 30 years solving building science related problems and educating the building industry professionals. His work focuses on increasing the quality, sustainability, energy efficiency of construction and reducing costly mistakes that lead to construction defects and call backs. Easley says most callbacks are due to inadequate knowledge about building science and how to employ it to improve the construction process. In a recent interview, Easley outlined five things that builders can do to reduce the likelihood of comfort callbacks:
- Integrated Design –“Builders should think things through and clearly communicate goals so that there’s no guess work in the field when working with different contractors,” Easley said. Homeowners value energy efficiency and comfort; optimizing both of these starts with the design process and involves consideration of all aspects/contractors involved. He recommends advanced framing techniques to maximize energy efficiency and comfort. Typical homes have framing factors of around 25 percent (25 percent of the opaque walls are wood leaving 75 percent left for insulation). This can easily be reduced to 13-15 percent with advanced framing, which will ultimately save builders time and money in framing costs, according to Easley. He recommended the American Panel Association’s Advanced Framing Construction Guide as a resource for builders.
- RESNET Grade One installation – Proper air sealing and insulation installation is critical to home comfort, Easley held. “The more efficient the envelope, the less money homeowners will spend and the greater the comfort.” In addition envelope improvements like insulation last for the life of the structure – they don’t wear out. There should be no gaps, very limited compression and no missing insulation, if your contractors are working to RESNET Grade One installation. Easley worked with Sean Junker, CEO Providence Homes to help the company make their homes more energy efficient, achieving HERS scores in the low 50s using batt insulation (see related story). The company is a production builder that constructs roughly 200 homes annually.
- Blower Door Testing – Because air infiltration has a huge impact on comfort and energy performance, Easley recommends blower door testing. This testing, required by jurisdictions that have adopted IECC 2012 and 2015 measures the air infiltration of the home. “Again, once you start measuring contractors work product, they learn quickly to do the job right,” Easley said. Even for locales that don’t require blower door testing, Easley recommends it as another all-important means of measuring. “This testing is a good way to evaluate performance and can be done at relatively low cost.” Prior to conducting the testing, Easley advises that contractors review the Energy Star Thermal Bypass Inspection Checklist, which requires visual inspection of insulation to ensure proper alignment with barriers.
- Size HVAC Systems Properly— Improperly sized HVAC systems are a common problem that can contribute to comfort issues. “The HVAC industry hasn’t paid close attention to changes in the energy codes, so a builder may end up with an HVAC system that is grossly oversized for the home and duct work that is undersized for the system or installed in a way that doesn’t get the air flow through the system, impacting the delivery of heat and air. The combination of an oversized systems as well as constricted and often times leaky ducts could result in duct leakage of 15 to 25 percent to the outside – and leaky ducts in a home can cause pressure differences that can lead to moisture problems,” Easley noted. He recommends properly sizing the unit and conducting heating and cooling load calculations based on the Air Conditioning Contractors Association (ACCA) current version Manual J or approved software that accurately calculates the load for the home. Also ACAA’s Manual D can be used for determining correct duct work design. “If you have an efficient enclosure your loads are less, HVAC equipment is smaller with greater potential for comfort and not paying to heat and cool outdoors – no fancy equipment and technology needed -- just reducing the loads to begin with.”
- Rate and Measure the House as Built, Not as Designed — “Homes are built with thousands of pieces put together by hundreds of people. Even if they are designed the same, they may be constructed by different sub-contractors, different work crews in different conditions, thus they won’t all perform the same,” Easley asserts. Having an independent third-party rater, such as a HERS Rater, evaluate each home can make a big difference.
Focus On the Envelope, Please
Easley contends that in even in the age of widespread use of technology in home building, it’s the low tech practices that ultimately have the greatest influence on home comfort. It all begins with the building envelope – and the quality of insulation installation plays a major role in comfortability. “If you get the envelope right – comfort is dramatically improved,” he noted. “Good quality insulation installation is the best way to get a high performance home. Builders can achieve excellent performance with inexpensive materials installed properly and measured for quality. This will mean a comfortable home for the homeowners and fewer callbacks for the builders.