Maryland

Statewide summary — confirm with your building department before designing

Ground snow load corrected from 20 to 25 psf by audit. Under ASCE 7-16, Baltimore, Annapolis and the Washington suburbs in Montgomery and Prince George counties are 25 psf, which is roughly two thirds of the state population; the stored 20 psf under-stated the load for all of them. The lower Eastern Shore is lower, with Salisbury at 20 psf and Ocean City at 15 psf, while Garrett County in the western mountains falls in an ASCE case-study area where no mapped value applies and a site-specific study is required. No other value on this row was changed. Ultimate design wind speed 115 mph covers the Baltimore and Washington corridor, where site values run about 112 to 114 mph, but it does not cover the Atlantic coast: Ocean City is about 128 mph and Salisbury about 119 mph. Seismic design category A holds for Baltimore and the Washington suburbs on short-period spectral response at Site Class D and Risk Category II, though the full ASCE 7-16 determination puts them at B; this distinction does not change residential requirements. Frost depth 30 inches matches common Baltimore area practice, but Maryland sets frost depth locally, western Maryland is deeper, and this figure was not verified against any government source. The termite designation heavy encodes the IRC moderate-to-heavy band, which is the correct band for Maryland, but this was not confirmed against a Maryland authority. The winter design temperature is ASHRAE data, is not published by any Maryland authority, and is unverified. SNOW LOAD AUDIT, 2026. snow_load_min_psf and snow_load_max_psf are left null, and no value on this row was changed by this pass. Maryland has a statewide code but no statewide snow load. COMAR 09.12.51.04 incorporates by reference the 2021 International Building Code, the 2021 International Residential Code for One- and Two-Family Dwellings and the 2021 International Energy Conservation Code. The Maryland modifications set out in that regulation are extensive but they run to fire protection, accessibility, energy, mechanical, plumbing and electrical subjects; none of them amends ground snow load, wind speed, seismic design category or frost depth. COMAR 09.12.51.05 makes those codes as modified the Maryland Building Performance Standards and applies them statewide, while permitting a political subdivision to adopt local amendments that address local conditions. Local amendments must be reported to the Department at least 15 days before taking effect, or within 5 days if adopted as an emergency, and where a local amendment conflicts with the state standard the local amendment governs within that subdivision. A subdivision may not weaken the IECC, Chapter 13 of the IBC, sprinkler provisions or wind design provisions. Snow load is not on that protected list. The net effect is that the IRC's own instruction stands unamended in Maryland: the jurisdiction fills in Table R301.2, and there is no Maryland table, map or county list from which a state minimum or maximum could be read. Because the Department of Labor publishes nothing, min and max are null rather than estimated from neighbouring data. The 25 psf in ground_snow_load_psf came from an ASCE 7-16 hazard read, not from a Maryland publication, and no Maryland authority publishes it. The Garrett County point recorded in the earlier audit is the single most important caveat and is worth restating rather than softening: western Maryland falls in an ASCE case-study area where the map declines to give a value and a site-specific study is required. That is not a hole in this research, it is the model standard refusing to assign a number, and it means a Maryland maximum is genuinely unmappable rather than merely unlocated. Frost depth of 30 inches likewise has no Maryland government source, is set locally, and is deeper in western Maryland.