IBC 1106 sets how many accessible parking spaces a lot needs, scaled to the total number of spaces, with a required share designated van-accessible. ICC A117.1 (502–503) provides the dimensions: stall width, the adjacent access aisle, van clearance, and the accessible route that connects the space to an accessible entrance — plus the signage each space needs.
The common mistake isn't usually the count — it's undersized access aisles, van spaces without the added width or vertical clearance, or an accessible route that crosses a curb with no ramp.
Reviewers check the accessible count against the lot total, confirm the van provisions, verify aisle dimensions, and trace the route from the space to the entrance to make sure it's actually usable.
This guide describes the model code for general understanding and is not a substitute for the adopted code and amendments enforced by your local authority having jurisdiction. Verify all figures against your jurisdiction's codes of record.