I have a commercial project which just broke ground which incorporates SIPs into the envelope. Although touted as a “green” product, I still have some reservations about using foam in a building. From some research I have conducted, the type of foam typically used in SIPs is innate, but there is still something in the back of my mind that worries me about the product. There is another product called Agriboard, which is basically the same thing using renewable agricultural products; however the increased cost and the fact it needs to be shipped from Kansas is another set of problems.
For those who don’t know what a SIP is, it can be broken down into simple terms: it is foam sandwiched together by plywood or OSB (oriented strand board). Is has a superior R-value (which is the resistance to heat flow, or insulation rating) and makes a much tighter envelope (less air seepage) for the building. It is designed and built in a shop and sent out onto the site to be assembled – I like to tell people its like putting together Lego’s, but the SIP guys don’t really like the simile.
Although used in residential construction, it is not fully harnessed in the commercial world. Our company has experience installing Agriboard on banks with success, but other than this application I do not know firsthand of any other commercial projects which have actually been built. When I initially designed the building, I had planned this single story building to be conventional steel and metal stud construction, but ran a few numbers with SIP manufactures and found that it was nearly a wash. To maintain flexibility, the main structure of this project is steel, and the envelope (roof and walls) are made of SIP. Market conditions helped make this cost swap happen, and with timing every project will be different, but I am pleased to say it worked out on this one (and before construction documents were well on their way), despite many architects telling me that they have pushed this building type and it has always come back “too expensive.”
As I mentioned, we just broke ground on the project. I can, however, speak to the design side thus far. The product’s best application is the roof as far as helping the efficiency of the R values. With windows, the gain has less of an impact. But the system itself allowed me to resize the mechanical units as well as the electrical service that goes to them. From a scheduling point of view, it has allowed me to greatly speed up my schedule. Once the panels are erected, I can set our windows and mechanical units and have a dried-in building while the stucco and stone are applied to the face of it. There are some conflicts I know will arise (such as protecting the window system from the masons), and I’m looking forward to working through them.
This building will not be a LEED certified building, although it will be certifiable. I am, however, looking at getting the designation Designed for the Energy Star designation.
Update: view this post for an update during construction, nearing the end of SIP installaiton.
[...] I wrote in this post about my project with SIPs before we had even started moving with them Now, we are near completion of the SIP installation on our Medical Office Building which I wrote about some time ago. The roof ended up taking a little longer than I had hoped, but the walls seemed to shoot up pretty quickly. There was more prep work than I was expecting as well – we had to manually attach the splines (wood blocking which hold the panels together) on site, as well as cut a number of panels which we weren’t expecting. The system, or at least the system that I thought we would get, was supposed to be pre-cut for the wall Connection of roof panels. They are basically set in place and glued together. [...]