I really don't know how to really go at this so I can only recommend 'common sensical things' ...
Get references, and talk to the references; contact the BBB in the area in which you live and in which they 'operate' out of; hire a Real Estate Attorney to look after YOUR interests (you know they have one back 'home'); Hire an ASHI-Approved Home Inspector to make at LEAST 5 'visits' to the job site during construction (foundation, framing, roof+siding, wiring+plumbing, finishing. Maybe more if you can.)
The latter 2 are the MOST important in my book. If you're saving some $$$, take some of that $$$ and hire a couple of people who are looking after YOUR interests. Here, in Southeastern PA, an Attorney for this will cost less than $750. And a Home Inspector for 5 visits is about the same, maybe less. To me, this is $$$ well-spent. Try to find an Attorney and HI that are familiar with the paperwork and 'inner workings' of a pre-fab home. If you find an Attorney and/or HI that isn't, ask them if they know someone. Ask the ASHI folks at the WEB site I listed. Ask your local BAR Association. Ask a Municipal Inspector.
Beyond this, talk to the Attorney and HI BEFORE you select a Builder so they can tell you what to look for. Don't hire a Builder only to find out either/or have something 'bad' to say about the Builder. Take their advice and the rest should be easy. The Attorney will make sure you get EVERYTHING in writing and the HI will make sure the 'guts' of the home meet the minimum BOCA.
Maybe others will have something to add. For now, my best to ya and hope this helps.
Jay J -Moderator
PS: Maybe when you've hired an Attorney and HI, you can let me know how it's going. Certainly, I'd like to learn something from YOU ...
Pre-framed shouldn't take much longer or less. The actual framing only takes a week or two, depending on the weather, etc. The real time comes in the rest of the work - electric, plumbing, insulating, drywalling, etc.
One other point - its not as much stick vs pre-framed but how good the builder is.
Talk to some folks living in homes your guy built; preferably 5 years old or more. This gave us great insight. Ask them how the builder was on warranty items. Trust me there will be some warranty items. Ask them if the house was completed on time. Find out what they would do differently if they could do it again.
Find out the normal lead time for permit approval in the city where you are building. It was 3 weeks where we built. This added 3 weeks to the builders estimate.
Be prepared to devote some time immediately picking out tile, carpet, faucets, light fixtures etc. It seems like at first you have plenty of time and then everything hits at once. The last thing you want to do is hold up the process yourself.
And as someone said, visit as often as possible. See if things look right. We found the most crucial time was during framing. It is easy to move a wall or door before wiring, plumbing and drywall are installed.