Case Studies

The case studies in this project are designed to inform designers, architects, builders and subcontractors about the benefits of, challenges of, and best practices for building with ducts inside.

The case studies were selected to represent diversity in the residential marketplace, and include urban infill, suburban, one-story, two-story, custom, speculative, and production-built homes. The builders included in the case studies currently build homes in Oregon, Washington and Idaho, so the homes are located in either marine or cold climates. All of the builders are certifying their homes to one or more of the following green certification standards: ENERGY STAR®, Earth Advantage®, LEED® for Homes, BuiltGreen®, or NAHBGreen®.

Building with ducts inside provides a clear path for meeting part of the energy efficiency requirements of these programs. The diversity of home types and locations led builders to adopt different approaches to bringing the ducts and air handlers into the conditioned space. Five builders used open web floor trusses, one builder conditioned the home’s crawlspace, and two builders used dropped or inverted soffits. The builders varied in where they placed the air handler, locating their conditioned mechanical rooms in the garage, second-story closet, or attic.