Jeff Bentley is a fifth-generation home builder who’s built more than 4,000 houses and sold more than 2,000 homes in more than 45 years in residential construction. He’s also a HERS rater, LEED Green Builder and REALTOR® whose counsel on energy-efficient home building is highly sought after. Insulation Institute reached out to Bentley to find out what practices can help builders meet more stringent energy efficiency code requirements and dramatically improve the way homes are built in America. Here are Bentley’s four rules for high-performance homes.
Rule #1: Train Continuously
Having worn many hats in the residential building industry, Jeff Bentley brings unique perspectives to evaluating modern homes, but readily admits that it wasn’t until he added more titles to his resume that he understood much about building science. “As a builder for so many years, I thought I knew a lot, but it wasn’t until I started studying to become a HERS rater that I really understood building science and why constructing homes for durability, indoor air quality, and energy efficiency is so important,” he said.
A 2016 conversation with TexEnergy CEO Steve Sanders about the challenges many builders were having in meeting Texas’ new residential building energy code requirements convinced Bentley that he should pursue HERS rater training and eventually, teach other builders how to construct better quality, more energy-efficient homes.
“Over the years, I went from being a full-time builder–at 25 with 42 houses under construction–to learning about building science and teaching other builders why it’s so important,” Bentley said. “Now I consult, speak, and teach high-performance home building to builders, REALTORS® and appraisers throughout the country. Many builders are having some of their toughest challenges around air sealing, primarily because they don’t understand wood framing. Anywhere two pieces of wood come together is a potential pathway that must be sealed in order to get a tight home.”
Bentley says there was a steep learning curve in Texas in the lead up to getting builders, who routinely constructed homes with 7ACH50 blower door tests, down to 3ACH50. “I was up at the crack of dawn every day to consult with builders to show them how to get 3ACH50–I taught them how to seal, and where to seal, which was important to getting the scores they needed.”
“Having multiple contractors on job sites building homes while having no knowledge of building science is a recipe for poor quality construction,” Bentley explained. “In May you can look out on job sites and see college kids with no other job, and some of them will wind up framing houses, but none of them know what they’re doing,” he said. “But it’s not just the framers, all of the contractors involved in construction and the super on the job need to understand building science if the goal is constructing better quality, high-performance homes,” he added.
Bentley also noted that there’s an unmistakable attitude that ultimately leads to better building: top-down commitment by the builder.
Rule #2: Emphasize Commitment from the Top Down
“There are really good high-volume builders out there who are able to get 3ACH50 in almost every house because of the commitment from the top of the company that is enforced throughout the building process.”
You can’t teach commitment, but you can look for contractors who will bring the same level of focus and detail to the job as the leadership of the company. “A contractor who’s in a hurry isn’t paid to care–they will tell you that. The importance of getting uniformity and consistency in construction is essential to delivering a quality finished product. The whole building process needs to be turned on its head so that everyone from the top down recognizes that the number one priority is delivering a quality product to the buyer.” Bentley noted.
Rule #3: Verify the Work
In training framers, contractors, and builders, Bentley says he underscores the importance of air sealing every seam where wood meets. “There has to be someone teaching this to another person–usually the super, who is inspecting the work done, to make sure it’s done properly,” he said. “I usually go out to the job site and inspect as the poly seal is applied then go out again to inspect when the batts are put in, to make sure there’s no compression or holes, which can reduce the insulation performance,” he added.
“Air leakage pass/fail should be part of every subcontractor’s agreement with the builder, and someone should be responsible for verifying that the job was done properly. I think all supers need to be energy rater certified. They should understand how homes perform and why these elements of the build process are so critical–especially because they ultimately impact the performance of the home.”
Rule #4: Be Willing to Evolve
The drive to build more efficient homes will require that contractors and building superintendents be more knowledgeable than ever before–not just about energy efficiency, but indoor air quality. This is particularly important with newer homes being constructed tighter than ever. “A house with high infiltration brings some bad stuff under negative pressure–things that are harmful to a person’s health, that’s why mechanical ventilation is so important.”
Bentley believes builders must evolve and shift their focus to tighter envelope construction (he’s a fan of Passive House’s 0.6ACH50 air change rate), with adequate mechanical ventilation and high-efficiency water and HVAC equipment in order to deliver better-performing homes to buyers. He also sees an opening in the future for increased use of items like insulated concrete forms and structural insulated panels instead of wood framing, as these would eliminate thermal bridging that occurs with wood construction. He’s a realist about the financial implications, though. “If there’s more competition in that market and costs start to come down, more builders will be interested, but until then, the focus has to be on better quality framing, tight envelopes, and thorough air sealing.”