I've been searching for a good few days now to see if there's a fix for this issue, with no success. The problem is slightly driving me up the wall so I thought I'd ask here, as you seem to have more expertise in building for TS3 than the rest of the Sims Community at the moment.
I'm building a small Arts and Crafts type home and they often have mixed roof types, but every time I attempt to use a combination of the Gable and Octagonal roof, the game generates holes in the roof. Here's a picture that demonstrates the issue.
I can use the a crappy hipped roof and I likely won't get the holes, but then the shape just won't be right for the period.
Has anyone here found a fix for this issue or is it just EAxian bad coding I'm going to have to put up with?