One of the first things I do on a project like this is set up all my technical drawings and references to scale in 3D space. No sense in starting a model if the different elements aren’t even to the same scale. So when I started this project, sure enough, I was careful to set up all my reference images to scale.
Or so I thought. I just discovered an issue with the vertical scale: it’s around 3-4% too short. I don’t think the issue extends to the horizontal dimensions; I just need to stretch some of the elevations vertically. (The elevations in question are Prisoner of Azkaban drawings; I’m using perspective-corrected photos of blueprints at the Warner Bros. Studio Tour in London, so there was always the potential for the vertical scale to be wrong, but I thought I’d already fixed that.)
I know that a few pieces of very useful height data can be found in a drawing in Harry Potter: Page to Screen, which I really should have picked up a long time ago anyway, so I’m off to Barnes & Noble later today. Then I can start the arduous process of figuring out which elements of the model need to be fixed…