I am aware of the Stronghold Builder's Guidebook (WOTC), but it seems very flawed to me in places, so I was wondering if anyone knew of any other resources for creating buildings? Or maybe errata or a 'fix' for the SBG?
I am waiting for the Ultimate Campaign to fix some of this. Sadly, I was not aware of it until it was already closed for playtest.
As a former engineer (admittedly industrial, not civil) I was always trying to construct stuff in various fantasy RPG settings.
The Stronghold Builders Guidebook is flawed, as it is really designed for the d20 economy. The Kingmaker Adventure path has an abstract on building creation if you just note that 1 build point is 4,000 GP.
If you need detailed rules, pick up an old copy of Chivalry and Sorcery, book II. They have detailed and unanachronistic rules. The Forge, a Polish company that has English products too has two books, "Manor" and "Barony" that are useful and a great balance between medieval historic realism and game statistics. Lastly, the book A Magical Medieval Society by Expeditious Retreat Press contains detailed rules for buildings without getting into engineering level stuff.
P.S. And always remember every wall above needs a wall below. Nothing frustrates my engineer sense than a one foot thick wall in a castle without a wall underneath it. Stone does not float! Exceptions in the case of properly constructed arches, but that is beyond the scope of this rant.