Sustainability is a vital part of home builders’ vocabulary in 2023. But how do builders work to shorten and improve the supply chain to benefit everyone involved?

Kathleen Hetrick, a sustainability engineer with Buro Happold, is one of the authors of "The Regenerative Materials Movement: Dispatches from Practitioners, Researchers, and Advocates." She spoke to BUILDER about supply chain considerations, unsafe materials in the home, and advocating for a net-zero supply chain.

Why should home builders consider the entire supply chain during construction?

A home is like any other product. When selecting clothing for your children, you want to know all the possible risks. If I get a cheaper version, will it impact my family’s health somewhere down the road? Is it aligned with my values?

And I think for [Buro Happold], thinking about the supply chain and construction—for so long, green building has only focused on the occupant, and that's sort of why we ended up with cost escalation in our supply chain. We don't have local supply chains anymore. There's not a lot of transparency. There's a lot of middlemen.

Let's take a step back and look at the whole picture. I think we're going to have more secure supply chains. I think we won't have the issue of greenwash. We'll know where our materials come from. They'll tell a story, right? It's like when you go into beautiful homes. I live in California. We have a lot of beautiful, historic houses built with high-quality goods that came from the area. That's what we're talking about here.

Do you think the housing industry is guilty of greenwashing to appeal to today's consumers?

I don't think it's necessarily greenwashing. I think you don't know what you don't know—and having your eyes open to the revelation that there could be supply chain abuses in your labor supply or down to where your materials are manufactured.

People are concerned about chemicals like per- and polyfluorinated substances (PFAS) in our drinking water. And people don't know that they could also be associated with the materials we're building. It's really about education, and not every builder or consumer will have a degree in toxicology.

But a big part of that is advocacy, too. We need enlightened home builders to think about these questions and ask them because that's how we change the market. That's market transformation. If you're worried about where your steel or wood floor comes from, you start asking those questions, and the manufacturers will clean up their act and get you the products you want. If we don't think about it, they won't act. It's just human nature.

Can you tell us a bit about the Red List?

The Red List has been around for a while. It's from an organization called the International Living Future Institute. They published the worst chemicals and the worst materials that you can kind of come across in the built environment.

There are things like asbestos and lead; those are completely naturally occurring products. They're mostly out of our supply chain here in the U.S. Unfortunately, certain types of manufacturing for materials such as PVC, for example, can be used to produce mercury and asbestos in their manufacturing.

So again, that's the whole supply chain. You need to be thinking about your manufacturing workers encountering these issues if you're thinking about ESG (environmental, social, and governance). But the [Red List] has many of the more common chemicals we encounter daily in our homes. It’s making sure we don't have formaldehyde in our flooring.

In the book, you specifically referenced PVC as a material that needs to be replaced. Are there other specific materials in traditional home building that are just as troublesome?

It’s things like formaldehyde, which we have done away with in a lot of our building products, especially in California, as opposed to other parts of the country. It's such a commonly found material that manufacturing groups are rallied behind getting formaldehyde out of our supply chain.

I would also say that it's very important that when people are concerned about energy efficiency, saving money, and doing the right thing, insulation can have a lot of formaldehyde. It could cause issues with people's health from the get-go. When you're crawling into an attic installing it, and you must wear protective equipment, that's usually a sign.

Plastic is going to be found in a lot of our buildings' petrochemicals, and we're not at the point where we can move away from that. There are some of the worst plastics and petrochemicals, like extruded polystyrene or XPS boards. Not only are they harmful to the planet because they're super energy intensive to produce, but they use very high-polluting types of chemicals to make them, and the ingredients to make those are toxic.

One recommendation is to take a strong look at your insulation. Look at the more natural materials—wool fiber, cork—certain minerals are all very safe formaldehyde-free and help you get those energy-efficiency savings. If I could recommend one thing for people to start with on the Red List, it's to look at your installation. Look for Red List-free insulation.

Also, consider anything that needs to be applied wet—if you’re painting your room or you're putting down new tile or carpet, and there's a sealant involved. Those are going to be your highest concerns. You know when you want to get that fresh paint smell? That's not necessarily a good thing for your health.

Flooring is another issue. We've been building homes for centuries. We don't need to rely on stuff harmful to our health and our planet. We don't need vinyl flooring. It's something to avoid; we must be careful about the PFAS we're reading about in the news. These floors need forever chemicals that might be used as a stain or sealant on your floor. You want to be avoiding them.

You want to think about natural products. Can you be smart about having a polished concrete floor or having ceramic tiles? Maybe they're made from the clay in your area, and that gives you a story for your home. Or there’s refurnished wood flooring and even linoleum that can be used. Linoleum is naturally derived. It's affordable.

There are beautiful aspects of linoleum—it's not just what you can remember from a 1950s kitchen. I am a big lover of linoleum because it gives you a lot of the durability that people are looking for. It's a great finish with no health issues you see with vinyl.

How close are home builders to achieving a net-zero supply chain?

The first step is education. I think we will see a huge surge toward our carbon goals for our supply chain, which comes from market advocacy. It’s about choosing the manufacturers that are doing the work. We want to reward those manufacturers so that all their competitors realize, 'Hey, we’ve got to jump on this bandwagon too.'

I wouldn't say we're too close to achieving a net-zero supply chain. It's tougher than achieving a net-zero home; the grids are cleaning up, and solar has many tax incentives.

But luckily, I think education around the supply chain is changing. So many federal incentives are coming out right now to help manufacturers clean up their act. I think we're making some exciting progress. If we have healthier buildings, we'll have fewer issues of asthma, fewer allergy issues, and we’ll make things safer for manufacturing workers. Everybody wants their home to be a story of health.

Let's get back to how we used to build. Let's get back to building with natural materials. Let's use our innovation to make our products cleaner and more efficient. After that, I think we’ll start to see costs come down, and that’s exciting, too. We must have that curiosity to care about our health. We must consider it an advocacy position, and then we'll all benefit.