So much has happened since I posted my concept for this wall system back in Jan11. I've had dissatisfying discussions with fiberglass insulation makers. Very positive contact and support from Mineral Wool insulation maker Roxul, I've visited Bensonwood's facility in New Hampshire and seen their wall systems and their fabrication process first hand.
Regular readers know I have proposed this wall system as an easy first step towards high efficiency for builders who have not tried green building before. The goal was to make a wall design that performed significantly better, yet used the same materials and techniques as status quo walls. The idea is that builders can use the same subs they already have relationships with and the same suppliers they get materials from. They don't have to try new materials which they are unfamiliar with, new subs they have not worked with before, nor estimate time and cost with unfamiliar process. All deal-killers for getting status quo builders to try something new.
The configuration of the USA New Wall, as people have begun calling it, is based largely on configurations I've observed while studying Swedish factory built houses. The Swedes house building is based on stud framed walls similar to ours, but they have spent the past 30-40 years slowly improving the performance and efficiency of their techniques. As such their stud walls today are an evolution of the crude and inefficient walls we commonly build in the US. Its an ideal model for what our industry should do to improve our building. I intend the USA New Wall to be a guide for how to do that. Our construction materials and practices are slightly different, so we can not copy them directly. You might say we need to translate.
One of the issues that needs to be considered is the climate zones. I've begun with a heating climate wall, but in the US Department of Energy divides the country into seven climate zones, the coldest being zones 6&7. Sweden being a much smaller land area does not have this range, and in fact is probably most similar to our zones 6&7. In the US our Zone 5 covers a great deal of area and is a lesser heating climate, and is likely to almost always have air conditioning for summers. In the US we can find air conditioning in Zones 6&7 as well, but in Sweden this would not be the case. Air conditioning of course changes the vapor profile of the wall in the summer months and requires a different response in the design of the wall. So we need to extend the Swedish model so to speak, to make configurations appropriate to climates that don't exist there. This is the work that I've been doing since January, and I have profiles for walls in zones 4,5,6, & 7 worked out. I am still considering the best way to document these and where and how to distribute them. I will start with discussing them here in the blog in upcoming posts.