While Z scale would technically be closest, a lot of N scale buildings would work, mainly because most model RR layouts are heavily compressed, and building footprints are significantly reduced. The height of the building is generally close to the scale as stated, but the footprint is drastically undersized: a church steeple ends up being 3x or 4x the width of the building in height, and there's only enough room inside the building to seat perhaps 20 people, rather than 200. An apartment building is the right height, but all of the apartments are only 4' by 8' in width and length. Unless you're talking about downtown Tokyo housing densities or higher, that's seriously undersized.
I've built a number of structures for BattleTech scenery using everything from Styrofoam and cardboard to cast plaster blocks and sheet plastic. There seems to be a significant niche market for pre-made 1:285th scale sci-fi structures at an affordable price, but nobody seems to have found an affordable solution that's mass-producible and marketable.