Architectural Detailing - Edward Allen, Patrick Rand
Tolerance is the margin of variation from plumb and level that is generally acceptable in construction. Tolerances vary based on the nature of the material, the size of the module and methods for erecting. For instance, the tolerance for concrete masonry units (CMU) is quite small, about an 1/4" per floor but not to exceed 1/2" overall even for 20+ stories. Steel has a tolerance closer to 1/4" per floor but can vary by 1 or 2 inches at 20+ stories. This is due in part to the nature of the construction methods. CMU is placed in vertical 8" increments block by block and can be corrected for plumb every 8". On the other hand, Steel columns are placed every one to two stories, making correction for plumb much more seldom.