Massachusetts Building Design Criteria for Homes

Massachusetts replaced the model code's Table R301.2 with its own Table R301.2(1), which fixes the climatic and geographic design criteria for the whole state rather than leaving them to each municipality. Weathering is classified as Severe, which governs the frost resistance concrete and masonry must have. Termite risk is Moderate to heavy. An ice barrier underlayment is required. Flood hazard requirements are handled through R322 rather than in the table itself. The air freezing index is the one value that varies within the state, and it varies by county rather than by town: 2000 in Berkshire, Franklin, Hampden and Worcester counties, and 1500 in all other counties. That index matters mainly if you are designing a frost-protected shallow foundation, since the table points to R403.3 and Table R403.3(2) for that case. Windborne debris zones are defined by reference to Chapter 2 of 780 CMR 51.00 rather than listed here.

These criteria are design inputs enforced at plan review and inspection rather than offences in themselves. Drawings that specify materials or assemblies below the stated criteria, concrete not rated for severe weathering, or a roof without the required ice barrier underlayment, will be corrected at review or flagged at inspection before the work can proceed.