By Steve Byers
Attend an EEBA Summit or any other gathering of high-performance builders, and you will learn a lot about how to build healthy homes with great indoor air quality (IAQ). The attendees will all seem committed to building such homes, making it easy to conclude that health has become a priority for the industry.
The problem is that it hasn't.
I love these conferences because they attract the best builders, but they can also be an echo chamber. My interactions with code-minimum builders—who represent most of the industry—have taught me that for most, IAQ isn't even on their radar. This obviously begs the question of "how do we reach those builders?"
Helping them want to build healthy homes takes a stick and a carrot, with the two ends of the stick being liability and reputation. On the liability end, an asthmatic child developing problems after the family moves into one of your homes is a worst-case, and lawyers will likely be involved.
It doesn't even have to go that far; people need not actually get "sick" to notice problems. Indoor air quality monitors are available on Amazon for as little $110, and though most aren't particularly accurate (I've talked with experts who say that if you spend less than $500 on a monitor you're wasting your money), a lot of homeowners are buying them. Something as minor as a slightly elevated CO2 level could generate a warranty call or an online review that's a real hit to your reputation.
That hit will sting even more if you compete with builders who are enjoying the proverbial carrot. These builders understand the power of the healthy home message. Some participate in a program such as EPA's Indoor airPLUS (IAP), which provides them with a healthy home checklist to follow, while others have simply embraced IAQ best practices and emphasize those practices in their marketing.
If you're interested in building healthy homes, the first question is where to begin. I would like to suggest a good home energy rater as a starting point. I wrote in a previous article about how raters are an underutilized risk-mitigation resource, but they can also be invaluable when it comes to building a healthy home.
How Raters Help
While raters aren't healthy home experts per se, their basic diagnostic skills are the exact ones needed to ensure that your homes meet basic IAQ principles. That's because the rater is trained to measure air leakage in the building envelope and the ductwork, both of which have a big impact on a home's air quality. Raters can also assess the performance of the ventilation system, another key to good indoor air.
High performance, healthy home builders live by the three-part mantra of build tight, ventilate right, and choose non-toxic materials. A good rater can help with all of these criteria.
1. Build tight. Besides measuring overall air leakage, a skilled rater will be able to use diagnostic tools like a blower door to both find and quantify the leakage.
This is crucial. Say the home has an attached garage. If the envelope between the home's conditioned space and the garage isn't properly sealed, pressure differences between inside and outside can easily draw in carbon monoxide from car exhaust and fumes from chemicals stored in the space. But you need to do a blower door test to determine if that's happening.
The trick is to remember that every air leak is a potential contaminant pathway. Your rater is trained to find these pathways. During the blower door test, the rater can simply feel around for those drafts or can use a smoke generator.
The rater can also make sure your ducts are properly sealed.
If the home has a forced-air system, a duct leakage test might show that a return running through that garage is sucking up those contaminants and dumping them into the home. Similarly, leaky returns in a damp crawlspace or basement might be a pathway for mold spores, while one in the attic might be sucking up insulation fibers. Anywhere that ducts are outside of the conditioned space they need to be well-sealed.
2. Ventilate right. With the envelope tightened up, the rater can help you choose the right ventilation equipment for your home and your climate.
3. Material selection. While material selection may not seem exactly like the purview of a HERS Rater, as with many other things, your rater is probably eager to be a part of the solution to your problems.
The name of the game in improving IAQ via material selection is to reduce VOC’s. While there are no easy answers here, there are resources that can help both rater and builder make more IAQ friendly choices. The Red List from the Living Future Institute is one such resource. The Indoor airPLUS program also has a list of standards and 3rd-party certifications for low-emission products.
Engaged, professional HERS Raters are always looking for ways to increase their value to builders. If you're a builder, you can suggest that you and your rater both become Indoor airPLUS partners and that your rater reviews the Indoor airPLUS Construction Specifications and suggests simple adjustments to your home package that result in certification. If you build enough homes to account for a large portion of the rater's business, you might consider making that a condition of work.
The bottom line is that while indoor air isn’t part of the HERS system by definition, it is certainly part of what serious raters should be thinking about and developing further skills around.
Steve Byers is CEO of EnergyLogic, Inc., a building performance consulting company in Berthoud, Colorado.