I want to give some perspective to the rough $/sf numbers that correspond with what I posted below. One of our goals when we designed this project was to keep the costs down. We were originally looking at just a single bar design, the most cost effective option, but that was pretty cramped. We talked about a double decker; we talked about a double decker with a half box for the second floor. Res4 was completely attuned to how to maximize space for the money, and walked us through which aesthetic and design elements meant how much money. A pitched roof, clerestory windows, decking, external stair modules - each of these has a pretty identifiable $/sf effect; the Dwell House, for example, has design components that correspond to additional costs that we won't have.
So by way of comparison of our house to something like the Dwell House:
-our module will only be one box, and it will sit on a walkout basement that has the same footprint. This minimizes the button-up process - literally just siding and constructing the stairs. The more modules, and the less footprint shared by the modules, the more "sewing" is needed to bring them all together (interior and exterior);
-our box is coming finished on the interior - floors, cabinets, trim, the works. There is literally nothing left to be done on the interior except appliances and the stairs (we were hoping it would even come with exterior siding, but no luck). Bigger projects will need to have the modules joined on the inside where appropriate, meaning the floors, trim, drywall, etc. need site work (though I get the sense from Res4 that they've got some bigger projects than ours in the works that are really maximizing the finish-level out of the factory);
-Res4 designed a "modified butterfly" roof for us. Instead of a separately constructed module unit that would come on its own trailer and need to be put together on site (with all the post-set work that entails), we've got a roof that is being built in the factory on top of the box. That means we need to live with an 11' height profile (max allowed on the roads), and lower ceilings in the house (9' ceilings on the interior at the highest part of the butterfly, and 7' at the lowest - there's a soffit that runs the length of the house). This reduced our cost significantly - the Dwell House's roof module prices out now at about $30/sf (but you get a wonderful 14' ceiling);
-the walkout basement really helps keep the cost down, and it's half the square footage of our cabin (though this is a smaller project at 2000sf, so a bigger building envelope would spread the fixed costs like the well, utilities, etc. over more square feet);
-our finishes are modest by comparison to what you see in a lot of the high-end modern stuff that's out there. Nothing "cheap," but certainly cost-effective.
That's all simply to say that our $/sf is probably a very low baseline for purposes of comparison to other Res4 projects.