Materials distributor 475, the New York City mail-order business that specializes in advanced airtight vapor-control membranes, tapes, and insulation products imported from Europe, has released a new book of high-performance building details specifying their family of products. The new publication, “High Performance 2x Framing,” is the third installment in 475’s series of similar detail books. The first two books in the series covered relatively uncommon building methods: the first release was about retrofits for historic masonry buildings (especially the brick row houses that are typical of 475’s New York City location), and the second focused on insulating and air-sealing wood I-joist assemblies.
This third book in the series aims at a more mainstream niche: walls framed using ordinary 2x lumber. The assemblies aren’t simple — far from it, in fact: the example wall sections involve built-up layers of interior and exterior continuous insulation and strapping, along with exterior drainage plane and interior vapor control membranes (below). Intersections where walls meet floors or roofs get complicated, not surprisingly. Flashing can be a puzzle. And the foundation, floor, and roof assemblies that round out the package are also pretty tricky to figure out.
But if high-performance energy-efficient construction were simple, there wouldn’t be any need for a collection of details. What the growing series of 475 books supply is a coherent approach to high-performance construction that prioritizes air-tightness ahead of superinsulation, minimizes thermal bridging, applies a sophisticated understanding of moisture control and drying, and meets the requirements of advanced assemblies using a single family of products that are designed to work together. Is it for everyone? Probably not. Is it worth taking a look at? Absolutely.
