This follows up on the previous blog post—so have a look at that first.
I have been testing the prefab waters recently, partly in response to client inquiries, and partly because I see the potential for an improved construction process. There are a lot of people out there who are very, very frustrated by the conventional, this-is-the-way-we-have-always-done-it method of construction. Stick frame residential construction in particular is not much different than it was 100 years ago, which is absurd. It would be like Tesla trying to use the same assembly line that Ford first used in the early 1900’s.
I looked into one promising modular house company recently. Their website is slick and shows very clean modern houses in spectacular settings—the houses would be right at home on the pages of Dwell magazine. Cool houses for cool people.
In looking into the details, I discovered that aspects of the house would not meet the BC building code and were very inappropriate for a wet coastal climate. The manufacturer assured as that their houses were ‘certified’ for BC, but whatever that means is useless because the local building department would not accept it. To their credit, the company did listen, and have since modified the design and details.
I have also been following another recent prefab house which is under construction. The prefab company budgeted 3-4 days to erect the shell of the house, but the actual timeline was over 2 weeks., which happened to coincide with a week of heavy rain. This is not to blame the prefab company, but there were logistical, site, and technical challenges that had not really been fully considered and had to be sorted out on the fly. The logistics of what gets delivered and when is extremely important and takes on huge importance. There are larger modular companies out there who seem to have a seamless, or nearly seamless fabrication and logistics process sorted out. But for most projects, it seems that there are plenty of unexpected scenarios and human error to cause some veering from a straight line. So count on them in spite of any over-optimistic claims of the marketing department.
I toured a very interesting factory recently that makes light gauge steel roof and wall panels (Lifetec, in Burnaby). Buildings are modeled for the most efficient structure, with the minimum wastage, and then the information is sent to the factory floor to be ‘printed’ by a CNC machine. The members are then assembled into panels and delivered to the job site to be erected. The facility and the process is impressive. Steel does have some drawbacks though: it acts as a thermal bridge and requires continuous exterior insulation; and it has larger carbon footprint than wood.
My recommendation to anyone considering prefab or modular: do your homework and ask lots of questions. Research the company and go over their details. Visit the factory and if possible, visit one of their finished buildings.