How building permits work in Maryland
These rules apply across Maryland. Each local guide above covers what is specific to that city, town, township or county: its building department and contacts, local rules, fees and inspections.
The Maryland Building Performance Standards
Maryland runs on one statewide instrument, the Maryland Building Performance Standards (COMAR 09.12.51), and enforces it locally. The state adopts each new edition of the International Building Code, the International Residential Code and the International Energy Conservation Code, with Maryland modifications, and every jurisdiction must adopt and enforce the same edition within 12 months — counties and the cities that keep their own permit offices may amend the building and residential codes to suit local conditions, but may make the energy code and the Maryland Accessibility Code only more stringent, never less, and may not weaken the sprinkler rules for houses and townhouses or the wind-design rules (Public Safety Article 12-504). The 2021 editions, effective statewide on May 29, 2023 with local enforcement required by May 29, 2024, replaced the 2018 editions; the Maryland Building Rehabilitation Code carries the existing building code beside them. The state proposed the 2024 editions in June 2026; they were not yet in force in October 2026. What is local in each county or city is the enforcing office, its amendments, its fee schedule, and the grading, stormwater, forest conservation and Critical Area approvals that run ahead of the building permit.
The codes draw the exemption line and the local amendments move it. The IRC's work-exempt-from-permit list — small accessory structures, low fences, minor repairs — applies as each jurisdiction adopted it, and the jurisdiction's own ordinance may narrow it. Electrical, plumbing and gas work need their own permits from the local office (from WSSC for plumbing and gas in its Montgomery and Prince George's service area), and zoning, grading and sediment control approvals are separate from all of them.
Prior approvals and plan review
A Maryland building permit is one application reviewed by the local office's plan reviewers for the building, residential and energy codes, with the electrical, plumbing and mechanical trades permitted alongside it. The approvals that run ahead of it are the ones that decide the schedule: zoning certification, a grading permit with a sediment and erosion control plan approved by the soil conservation district, stormwater management approved under the county's or city's own programme, which follows MDE criteria, forest conservation review under the Forest Conservation Act when the subdivision or grading application covers 40,000 square feet or more, and Critical Area review within 1,000 feet of tidal waters.
Maryland sets no deadline for deciding a building permit. For housing projects, since 1 October 2026 the office must decide within 30 days whether an application is complete, or it is treated as complete at 35 days, and the project is judged under the rules in force when it was submitted (Housing Certainty Act, Chapter 591 of 2026). Accessory dwelling unit zoning permits must be decided within 90 days.
Contractor licences and registration
Maryland has no state general contractor license for commercial work, but home improvement is licensed outright: the Maryland Home Improvement Commission licenses contractors who alter, repair or improve houses and condominium units, with an examination, proof of financial solvency, $500,000 of liability insurance (since June 2024) and a guaranty fund that pays homeowners up to $30,000 for a licensee's defective or incomplete work. Owners working on their own property do not need the licence. New construction is different again: a home builder registers with the Home Builder Registration Unit of the Attorney General's Consumer Protection Division under the Maryland Home Builder Registration Act, and the registration number goes on the permit — except for an owner building for their own use, and builders who work only in Montgomery County, who may hold a county licence instead.
HVACR contractors hold a state licence. Plumbers and gas fitters hold a state licence, except in Baltimore County and the WSSC area of Montgomery and Prince George's counties, which license them separately. Electricians hold a state licence, but a county or city may also require its own registration, and several counties keep their own trade boards, so check what the local office asks for.
Trade work is permitted separately from the building permit in most Maryland jurisdictions and inspected by the local office or, for electrical work in many counties, by a private inspection agency certified by the State Fire Marshal.