Home for Good A Healthier Future for Affordable Housing Passing by 506 Spruce Street in New Castle, Pennsylvania, you might think this early-20th-century house in the former manufacturing capital was simply getting a freshening up. The 800-square-foot dwelling is in fact the site of cutting-edge design and construction research led by Parsons’ Healthy Materials Lab in collaboration with local community partners. But to witness the home’s radical innovations firsthand, you would need to take a chainsaw to a side of the building. In a typical freestanding American home, an exterior wall has as many layers as the functions it performs. Wood framing is placed between panels and sheets dedicated to waterproofing, blocking drafts, insulating interiors, and finishing surfaces. While the assembly encloses a space effectively, the many individual components add cost and often harm occupants: The building products typically contain known asthmagens, endocrine disruptors, and other compounds that damage human health. Even lumber usually contains endocrine-disrupting flame retardants. The mission of Parsons’ Healthy Materials Lab (HML) is to reduce human exposure to such chemicals, especially in affordable housing. Jonsara Ruth, who co-founded HML with Alison Mears, says this work reached a turning point in 2017, two years after the collective’s launch. Observing that healthful materials advocacy focused on products that contain toxic substances, Ruth recalls realizing that “removing one harmful ingredient at a time is an important but slow process. So we convened a group of TOP: Project partner DON Enterprise recently purchased 506 Spruce Street to convert the property into a low-cost, nontoxic home for people with disabilities. MIDDLE: Perimeter walls like this one, made with sprayed-in HempLime, typically contain a variety of materials, which introduce added cost and toxics. BOT TOM: Lori Daytner, of the nonprofit developer DON Enterprise; Cameron McIntosh, of the hemp-building firm Americhanvre; HML research fellow Meryl Smith; and HML co-founder and design director Jonsara Ruth outside of 506 Spruce Street.
student researchers to identify available building products that best safeguard health.” This shift in HML’s perspective—from mitigating the effects of toxic substances in mass-market materials to promoting healthful alternative products—soon led the team to HempLime, a material made from hemp’s woody fibers; lime, a silica material from limestone; and water. The biodegradable mixture can be cast or blown into wall cavities to perform the functions of several layers of a typical wall section. It is naturally mold resistant, flame retardant, antimicrobial, vapor regulating, and insulating. Instead of off-gassing, HempLime continuously absorbs airborne toxics, even sequestering carbon 29
