A few months ago Tedd Benson launched Unity Homes, bringing his ideas about Open Building to flatpack prefab. Benson's houses were designed to last centuries, easily upgraded to the latest technologies, but built with techniques like heavy timber framing, that were costly and relatively slow. The Unity Homes were an attempt at marketing a more economical home more quickly by combining the best of both systems.
Flatpacking (or panelizing) a house has some advantages over modular construction; you can ship it far more economically and for greater distances, and you can get away with much smaller, cheaper cranes for assembly. The major disadvantage is that more of the interior finishes are done on site rather than in the factory, and that's what takes most of the time and money in a house these days.
However Benson's open-built system probably makes finishing on-site easier than most houses, since services are designed to go in accessible chases and behind removable baseboards.
In the video, Unity's Jay Lepple explains how they do the siding in the shop and get a better job. This is interesting; in most houses like this, the siding is installed on-site so that it can run continuously across panels, to tie the whole thing together and hid the fact that it is made from separate panels. Here, they have a gap to fill with some kind of flashing and trim.
It's not a house that would attract a lot of notice if it wasn't such an interesting mashup of building technologies, a bit of timberframe in the middle, flatpack on the outside, Open-built upgradability throughout. More at Unity Homes