Spray Foam Saves the Day in 70+ Year Old Maryland Homes

What energy savings and benefits can you get when you retrofit an old home, built almost 80 years ago? A homeowner’s association (Greenbelt Homes, Inc.) in Greenbelt, Maryland wanted to find out.

The community was looking for an upgrade to the overall quality of their homes within the larger Maryland county community they shared. Much more state-of-the-art housing has been constructed surrounding Greenbelt Homes in more recent years, and residents wanted to buoy their homes’ comparative value within this community. Specifically, they wanted:

  1. Energy efficiency improvements
  2. Increased comfort
  3. To reduce long-term home maintenance

The plan is to embark on a larger rollout of a decade-long community-wide upgrade in home energy improvements… but first, they needed to learn which materials and building products could provide the desired result, and if it was even possible to achieve the desired result by retrofitting these very old (some 70+ years) homes. Hence, a pilot project fully funded by the residents of the community was born.

One of the biggest issues to tackle during the pilot project was inefficient batt insulation, particularly in the crawl spaces below the homes, which contributed to poor energy efficiency. Proper air-sealing crawl space insulation was never implemented during the lifecycle of the building…and in some cases, where insulation had been added within the last 30 – 40 years, much of it had deteriorated. Thankfully, spray polyurethane foam (SPF) insulationhelped save the day!


Greenbelt Homes Pilot Program Report

From the report on the pilot project: Three to four inches of SPF insulation was installed in place of the fiberglass batts at the underside of the first-floor decks. The SPF provided an air seal in addition to a thermal resistance value of approximately R-6 per inch. The value of the new insulation brought the R-value of the floors to R-19 from an inconsistent R-11.

Besides this increase in R-value (a measure of thermal heat resistance), homeowners participating in the pilot noticed less draftiness after SPF insulation was added to the crawl spaces beneath their homes. Specifically, over 86% of all responding home residents said their home felt warmer (page 61). Nothing better than real life, real-time energy efficiency results!