It would be much less work intensive if you could get the layered image from the architect. They usually add the people and sky later, so the building should be on a separate layer. This way it will be much easier to build a 3d projection or an actual 3d space. For the latter, you can take the layers in Photoshop, cut the planes, distort them and rebuild the perspective with 3d layers in AE.
Tudor “Ted” Jelescu
Senior VFX Artist