Yikes! this new place is confusing!

Anyway,  has anyone out there had experience or an opinion on those “home energy rating systems” where they do a blower door test, check insulation levels, heating layout and so on, then assign a energy rating to the home?

I (an experienced carpenter, renovator, and some engineering training) have an opportunity to get into the business of providing the tests, and am wondering if many people use them, in particular new homes, or low-rise ici buildings.

Many thanks

Andy