Floors Over Unconditioned Spaces.
The State of Minnesota intends to adopt a new residential building code and residential energy code in late January or early February of 2015. This energy code contains revised requirements for vapor retarders, continuous air barriers and duct sealing, along with minimum standards for air-testing of materials and systems. One of the challenging elements of the exterior enclosure is the proper design and construction of habitable rooms above unconditioned spaces, such as tuck-under garages or parking garages. These floor system designs involve the possible installation of ducts, air barrier materials, and a variety of insulation types and insulation methods. The challenge is to determine what methods of design and construction could achieve the intent of code, best building practices, and long term durability. The Minnesota Building Enclosure Council will host a special workshop to discuss current best practices involving these unique floor assemblies. The meeting will start with a short introduction by Peter Kulczyk, founder of Green Building Knowledge, LLC. An open discussion will follow. The workshop will address considerations for occupant comfort, mechanical requirements, and advanced strategies for air and vapor management. Attendees are encouraged to offer input and suggestions for possible edits to the current code language. Objectives also include creation of visual representations or construction drawings that will clarify code intent while significantly improving the performance and constructability of these floor systems.