Gaithersburg Zoning Regulations & Building Permits Guide
Official references and local checks
Use the official references below to identify the rules that apply to your address, then confirm parcel-specific requirements with the local authority before filing an application.
Official references
- Population:
- 71,026
- State building code:
- Maryland Building Performance Standards (based on 2021 IBC)(statewide default)
- State ADU law:
- Yes — Maryland SB 891 (2025, Chapter 196, signed into law) establishes statewide policy promoting accessory dwelling units and requires counties and municipalities to authorize ADUs on lots with a single-family detached primary dwelling. The law took effect October 1, 2025, with local jurisdictions required to adopt conforming ordinances by October 1, 2026.
- FEMA flood map:
- Search flood zones
- Planning department:
- City of Gaithersburg Planning & Code Administration
- Municipal code:
- View code online
- Zoning map:
- View local zoning map
Before you apply
- Call the City of Gaithersburg Planning & Code Administration: 301-258-6330
- Search the municipal code for the chapter that covers your zoning district and proposed use.
- Use the local zoning map to look up your parcel's zoning designation before applying for a permit.
- Check FEMA flood zone for your parcel — flood-zone status changes setbacks, foundation requirements, and insurance.
- Check your HOA CC&Rs and recorded deed restrictions — they are common in Gaithersburg and frequently restrict ADUs, fences, and exterior changes beyond what zoning allows.
Key Zoning Facts
Gaithersburg Zoning Overview
Gaithersburg is a city in Montgomery County, Maryland that uses a zoning code to regulate land use, building height, setbacks, and density. The zoning code is administered by the City of Gaithersburg Planning & Code Administration Department.
The city recently completed a comprehensive zoning update called "Retool Gaithersburg" (approved July 15, 2024). This update modernized the zoning regulations while maintaining the character of different neighborhoods.
Development Process
Development in Gaithersburg generally requires obtaining the appropriate permits from the city's planning and building departments. The process typically involves:
- Zoning Verification — Confirm that your proposed use is permitted in the applicable zoning district
- Site Plan Review — For commercial and multi-family projects, submit a site plan for review
- Building Permit — Apply for a building permit with construction documents
- Inspections — Schedule required inspections during construction
- Certificate of Occupancy — Obtain final approval before occupying the structure
For projects that do not conform to existing zoning, property owners may need to seek a variance, special exception, or rezoning through the local board of zoning appeals or planning commission.
Key Contacts
- Planning & Code Administration: 301-258-6330
- Email: [email protected]
- Address: City Hall, 31 South Summit Avenue, Gaithersburg, MD 20877
- Hours: Monday-Friday, 8:00 AM - 5:00 PM
Important Note
For detailed information about specific zoning districts, setback requirements, ADU regulations, or other development standards, contact the Planning Department directly. The municipal code is the authoritative source for all zoning regulations.
Disclaimer: This guide provides general information about zoning in Gaithersburg and should not be relied upon as legal advice. Zoning codes are subject to change. Always verify current regulations with the Gaithersburg planning department or municipal code before making development decisions.
Regulatory Layers That Apply in Gaithersburg
Your property is subject to ALL of these regulatory layers. Each one can impose additional requirements beyond the others.
Federal
- FEMA flood mapping: check parcel-specific flood-zone status
- View FEMA Flood Map
State — Maryland
- Building Code: 2015 IBC (Maryland amendments)
- State ADU Override: Yes (Maryland Accessory Dwelling Unit regulations)
County — Montgomery County
- Role: County-level zoning oversight
City / Municipal
The municipality's zoning ordinance, building-code enforcement, and local permits form the primary local layer of land-use regulation for your property.
Overlay Districts
No overlay districts identified.
Private Restrictions
- Private covenants, deed restrictions, condominium rules, or association rules can impose requirements beyond zoning.
- Check HOA CC&Rs and deed restrictions for additional requirements.
Statewide Context (Maryland)
Local data for Gaithersburg is limited. The following state-level facts apply across Maryland and are inherited by this page until city-specific details are verified.
- State Building Code
- Maryland Building Performance Standards (based on 2021 IBC)
- State ADU Preemption
- Yes — state law overrides local rules
- Coastal Zone
- Yes
- Wildfire Zones
- No
ADU Rules in Gaithersburg
- Max Size
- Per Montgomery County standards
- Max Height
- Per zoning district
- Rear Setback
- Per zoning district
- Side Setback
- Per zoning district
- Parking
- Per Montgomery County standards
- Owner Occupancy
- Consult Planning Department
- Permit Timeline
- Consult Planning Department
Permit Costs & Timelines
Check Current Permit Fees & Timelines
Permit fees and review times can vary by project type, scope, valuation, and required approvals. Check the current schedule with the local permitting authority before filing.
Check current Gaithersburg permit information →Official Sources
City-specific