Deeper Treads Trip Up Builders It may seem like a small matter: one inch on the width of a stair tread, half an inch on the height of a riser. But the amended stair requirements in the 1996 version of BOCA's National Building Code (NBC) have ignited no small argument. The rule modification calls for stairs to have risers no higher than 73/4 inches, with treads at least 10 inches deep (previous versions of the NBC allow 81/4-inch risers and 9-inch treads). National Association of Home Builders (NAHB) members of the BOCA stair committee fought the change to no avail during the model code group's regular code amendment cycle. Now, many home builder associations are battling the adoption of the change by state and local authorities — with