These are my notes on some rough sizes I started to collect from some testing to help with planning 3D game level designs.

Building Size Standards

avg char height			1.6
avg eye level			1.5
avg char diameter		0.4
floor thickness			0.4
wall thickness			0.2
wall height			3.2 residential
wall height			3.6 commercial
door width			1.2
door height			2.2
stair rise			0.2
stair run			0.25
stair width			1.6
hall width			2.5 residential
hall width			3.0 commercial
tabletop height			0.7