r/prefabs

In 39 states the factory-built part of a modular house gets approved by the state, usually through a third party engineering firm working on the state’s behalf, and inspected inside the factory before it ships. It arrives approved. Your local building department only handles the foundation and the site work.

Eleven states have no program: Alaska, Arkansas, Delaware, Hawaii, Kansas, Mississippi, Missouri, Oklahoma, Vermont, West Virginia, Wyoming. There the modules go to whatever the local jurisdiction decides to do with them.

The architect I interviewed about this said approval in the easy 39 is “rather painless,” with the caveat that the local jurisdiction has to know the state program exists, and that many smaller jurisdictions aren’t familiar with modular projects and can be resistant. That is the easy version.

Then I checked the 71 builders in the directory I run against that list. Thirty four advertise delivery to at least one of the eleven. Nine advertise all eleven. Unfold House lists ten delivery states total and nine of them are on the no program list: https://modernist.live/companies/unfold-house

Hmm.

Nobody is lying. A truck goes where you pay it to go. But delivering a box to Wyoming and getting that box approved in Wyoming are not the same work, and only the delivery part appears on anybody’s website.

Interview, including what he says a manufacturer’s engineering package should contain and three things that went wrong installing his own house: https://modernist.live/experts/pedro-tavares

Has anyone here permitted a factory-built house in one of those eleven? How long did the local review take, and had the building department seen one before? Any thoughts? Please reply in the comments below.

Hey, guys, I just wanted to post this building my company put together this past winter using only purlins. It really turned out great, and the wind ratings, deflections, snow load, etc. were still really stout! Let me know if anyone is interested; we have standard pricing for these and can get them out quickly!

People here keep asking what actually happens on installation day and I had no real answer, so I asked someone who would know. Pedro Tavares is a principal at R&S Tavares Associates in San Diego. His firm does architecture and engineering in house for modular prefab projects and works in nearly every state, and several of the manufacturers I track are his clients. He also built a modular prefab house for himself. His answers were excellent, specific where most people would have been vague, and I am grateful he took the time.

The full Q&A, nine questions: modernist.live/experts/pedro-tavares

Three things went wrong on his own installation day. His shipper called the day before to say the trailers could not make the turn onto his street, so they moved every module onto different trailers with four forklifts. A ceiling module arrived from the factory with no insulation in it, and he bought batts at the hardware store and rolled them out before the next module came down. The crew installing his house started cutting holes in the floor rim to speed up the lift, in a spot the drawings do not allow, then billed him for the time spent cutting them.

I asked who is responsible when something gets damaged during the installation. He said he does not have a good answer and treats it as contingency money. I still do not know who would have a good answer, and it seems like something to settle before the crane arrives rather than during.

The other thing I did not know: 39 states approve and inspect the factory built part at the state level, so the modules arrive already signed off. He says that is faster than going through your county, as long as your county knows the program exists, and small ones often do not. The eleven without a program are listed in the Q&A.

I hope it is useful. I have more of these lined up, with an appraiser, a lender, and an installation crew, since those are the people who see the same problems over and over.

Pedro said he will answer follow ups. If you have a question about engineering, approvals, or installation day, put it here and I will send him the good ones for a follow up.