Evaluation of Crawlspace Retrofits in Multifamily Buildings

Stacey Rothgeb, A. Rudd, H. Loomis

Research output: NRELSubcontract Report


In 2011 and early 2012, Building Science Corporation (BSC) collaborated with Innova Services Corporation on a multifamily community unvented crawlspace retrofit project at Oakwood Gardens in Lansdale, Pennsylvania. BSC provided design consulting services and pre- and post-retrofit evaluation, testing, and data monitoring. The existing condition was a vented crawlspace with an uninsulated floor between the crawlspace and the dwelling units above. The crawlspace was therefore a critically weak link in the building enclosure and was ripe for improvement. Saving energy was the primary interest and goal, but the greatest challenge in this unvented crawlspace retrofit project was working through a crawlspace bulk water intrusion problem caused by inadequate site drainage, window well drainage, foundation wall drainage, and a rising water table during rainy periods. While the unvented crawlspace retrofit was effective in reducing heat loss, and the majority of the bulk water drainage problems had been resolved, the important finding was that some of the wood joists embedded in masonry pockets behind the brick veneer were showing signs of moisture damage.
Original languageAmerican English
Number of pages65
StatePublished - 2014

Bibliographical note

Work performed by Building Science Corporation, Somerville, Massachusetts

NREL Publication Number

  • NREL/SR-5500-62505

Other Report Number

  • DOE/GO-102014-4476


  • BSC
  • Building America
  • bulk water
  • crawlspace
  • embedded wood joists
  • moisture damage
  • multifamily
  • residential
  • residential buildings
  • unvented
  • unvented crawlspace


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