Spray foam has been the subject of much discussion in green building circles. Whether the concern is installation safety or global warming potential or better energy performance, it seems there’s no shortage of debate. Along these lines, the guys at 475 High Performance Building Supply, a Brooklyn-based provider of products for high-performance projects, have a list describing 13 ways foam fails, starting with the “dangerous toxic ingredients.”
Looks like wood-fiber insulation board is coming to the USA, according to a Greenbuild update on Green Building Advisor. Agepan THD is the name of the product and it’s used as exterior sheathing for walls and roofs. Agepan boards connect in tongue and groove fashion and insulate to R-5.74 per panel (2″ x 74.5″ x 23-5/8″). The material has a high permeability (18 U.S. perms) and can be used in a wall assembly to dry to the exterior. It’s offered through Washington-based The Small Planet Workshop Store.
I noticed in Dwell‘s Prefab edition that one prefab was partially built with an innovative concrete masonry unit (CMU) by Nevada-based Omni Block. Omni Block is a structural CMU filled with Expanded Polystyrene inserts. Walls with Omni Block can be finished or, in the case of the Simpatico project (see below), left exposed for a modern interior or exterior. The manufacturer says the material is fire resistant, durable, and thermally efficient, and the blocks come in colors or with special aggregates.