A Pittsburgh Couple Build Their Personalized, High-Performance Home 

"Modular was immediately appealing because it's factory-made, and all of the materials are inside and protected during construction, which is great for future durability," Spohn says. He also liked that the same crew worked on the modules every day, that the process is efficient with minimal waste, and includes ongoing quality control. Using laser alignment to keep things square for easy assembly, Spohn adds, the crew worked on the modules "from all six sides, from inside and out, and underneath and on top," for rapid, thorough, and well-integrated construction.

EcoCraft Homes in Pittsburgh and Structural Modulars, Inc., in western Pennsylvania, collaborated on the four modules for the Spohn home. "Those two companies have worked together for 15 years," Spohn says. "The boxes were built from the inside walls out, which is an important factor in home performance when it comes to airtightness," Spohn says.

The four boxes are each 14 feet wide, 11 feet tall, and 64 feet long. From the interior to the exterior, the high-performance wall construction includes drywall, 2x6 stud on 24-inch centers, and R-19 fiberglass insulation. Next came a ZipSystem® air-sealed sheathing system applied to the framing, with putty put over every fastener head for air sealing and for moisture resistance. A 1.5-inch layer of graphite-impregnated EPS rigid board followed, with tape and sealant at the seams to cover all the gaps for airtightness. Next was a weather-resistant barrier, and finally an upper-grade vinyl siding as the cladding. 

South-facing windows allow for solar gain in the winter, while sunshades and motorized blinds keep the sun out in the summer. The Passive House windows, provided by a local vendor, are triple-pane and argon-filled and tuned to a U value averaging about 0.15 and SHGC values between 0.39 to 0.42 to get more gain in the winter. The 8 X 9 patio door is also Passive House certified. Low-VOC finishes were used throughout the interior.

Since moving in, there are few things the couple would have done differently. They're currently working on planting a native wildflower meadow and are enjoying their outdoor flagstone and crushed limestone patio.