Best comparison of prefabricated house builders on a specific property?

If I understand your question correctly, you don’t want to compare prefab houses with solid houses, but rather compare prefab house offers from different manufacturers against each other.

Only an intensive study of the construction performance description and many on-site inspections of the processed quality help, a preliminary sampling, frequent reconfigurations (as quite a few things drop out that you don’t see at first glance). At the end of the day, prefab house providers will never be fully comparable with each other because, for example, the wall construction is different due to their ideology or the execution of one and the same detail is done differently... They do it the way they are convinced that a warranty can be given on it.

By the way, the houses in the exhibitions usually have a lot of special equipment, just like cars in a showroom. So there is a big difference between list prices from the catalog and the house you see in front of you.

The exhibitions / show homes are - ultimately analogous to the home builders / buyers themselves - emotionally and visually oriented. Additionally, they are meant to be somewhat of a showcase of performance, so I even find it sensible not to show just the basic equipment there. Customers mostly want to see special features, and because they have different tastes and everyone wants to see different extras, the show homes are practically "fully equipped" overall.

I would also look at the display homes from this perspective: aesthetic appeal and quality of workmanship. I would rather clarify the selection process in specialist trade exhibitions (bathroom exhibitions, etc.) and then actively incorporate it into the performance description once the trusted manufacturer has been found.

In the manufacturers’ selection centers, this can be done more compactly and quickly translated into concrete price effects. But even there, I would separate: visual matters in the show home, intellectual matters in the selection center.