Hello Richard! Definitely check out John Brocks “Estimator” extension. https://estimatorforsketchup.com/
He’s also working on a new extension called “SPOT”, single point of truth. It’s geared more towards interior designers and selections, but you might find its a little easier to use and covers everything you need. I would be more inclined to use SPOT as a residential designer. Estimator is better for builders and contractors.
Check out this video! https://www.youtube.com/watch?v=q-0PNL0sF_g&list=PL-bndkJaV8A4ofk43YYdTZaG4TJWqgOIa&index=12
Hit up John to get into the beta group for SPOT if you are interested. [email protected]