You do need cultural change too though. One way is to just demand visibility, not make any demands on actions. We have a published "energy class" for apartments and houses here. Our current apartment is class F or so - so we know our living cost is more sensitive to district heat prices than a class B apartment would be (those are newer and have in general higher purchase price).
However, it has its pitfalls and critics. Anyway, there the energy consumption is calculated from areas and insulation U values and so forth.
Don't know what would be the actual biggest problems against launching something similar elsewhere like in USA.
Probably one could build a software product to estimate these things. Especially easy during construction if the drawing data can be used directly. If things are drawn with CAD that is. But it might be relatively easy to estimate even from photos of paper drawings...
Unfortunately, the drawings don't give you any assurance that the construction details are done correctly. Corner-cutting aside, a contractor may depart from the design with good intentions and accidentally create a thermal bridge that sucks heat in or out of your house.
I think it's something that contractors even do in good faith. They read drawings and think, "Oh, I know a lot of ways to speed this project up, they're going to be super happy with my bid." They can see it'll be easier if they use a different material, move a door twelve inches this way, move the electrical to another wall, replace a difficult detail with an easier one, etc. They've probably worked on projects where those details are chosen without much care, and the client is delighted if they can speed up the project a bit by changing them.
In short, building contractors are a lot like software developers. There are some who keep up with the new materials and building systems and are excited to see new design techniques, and there are others who feel a sense of personal grievance that what they learned before they were thirty won't carry them all the way to retirement.