So here's a question.
Suppose the party wants to put a roof on a building that has no roof. And the moment comes when the ask the inevitable question, "How much will it cost?"
I find myself wondering about that, since I now have a system that provides costs so that the actual number of board feet can be estimated, multiplied against the cost and an answer produced. Which means that any player ought to be able to sit down, with the measurements of the building provided, and work out the cost for themselves ... by designing the roof themselves AND calculating the board feet. If they don't know how to design a roof, they can look it up on the Internet, follow a few principles they can read about, and educate themselves.
This is, after all, what I'd have to do. I'm not a carpenter. I don't know how big the roof would be, or how many board feet it would require to build. Moreover, is it really up to me to decide if it is a high peak or a low peak? Is this not a player's issue?
For that matter, if you, a real person, were to come across such a structure and decide to roof it, YOU would have to research it, and YOU would have to buy the wood. Hell, you'd also have to measure the building, wouldn't you ... and design a scale map for it if you wanted. Scale maps don't appear when you look at things, do they?
Now, I'm willing to go far enough to give the dimensions on the building ... I may even provide a scale map, if that were strictly necessary ... but if image presentation continues to move forward, why not just a snapshot from GoogleEarth circa 2017 to show what the building looks like, hm? Here's a pic, lay your own measurement grid upon it with your own design program, and let me know how much your roof it going to cost when it's done, hm?
Listen, a player is going to appreciate that roof MUCH more if he or she designs the thing before paying for it, right? Hey, I worked out the cost of the damn wood - which wasn't easy - and I have quite a lot of things to do already.
So here is the question. How far off am I to say to the player, work out your own design, and work out your own costs? Wood and stone cost such and such per board and cubic foot. Have fun.