Project Guides
Do You Need a Permit to Replace Your Roof?
Learn when a roof replacement requires a building permit, focusing on structural changes...
Read GuideCounty Guide · Verified 2026
ADU Construction Permits in Montgomery County, Virginia
Permit required
Check local building codes, estimate your municipal fees, and review inspection requirements for 2026.
🗺️
Statewide Guide
See the full Virginia adu construction rules — state code, thresholds, and how counties differ
Read the Virginia guide →
Local Project Overview
ADU Construction · Montgomery County, Virginia
Permit required
In Virginia, a ADU Construction requires a building permit.
An accessory dwelling unit (ADU) always requires a building permit because it adds a habitable dwelling, including electrical, plumbing, mechanical permits and egress/zoning review. Plans are reviewed under the Statewide code (IRC 2021); apply through Montgomery County Department of Permitting Services before work begins.
Source: Statewide, IRC 2021 · Verified 2026 by StateDataIndex
Building an Accessory Dwelling Unit requires complex zoning, structural, and utility permits.
With a population of around 99,101 residents, Montgomery County generally runs a more streamlined permitting process than major urban hubs.
Code Compliance & Inspections
Work on your ADU Construction in Montgomery County will be inspected to ensure full compliance with the current Virginia Uniform Statewide Building Code.
Concurrent Permits & HOAs
For Montgomery County residents, we recommend reviewing your neighborhood HOA covenants before paying any municipal fees. Homeowners associations often maintain stricter rules regarding materials and dimensions for your ADU Construction than the county itself.
Zoning & Cost Factors
Virginia follows the "Dillon Rule," meaning local governments only have the zoning powers explicitly granted to them by the state legislature. Fortunately, Virginia maintains relatively builder-friendly regulations, keeping base permit fees competitive.
Permit fees in Montgomery County
Permit fees vary by jurisdiction and by your project's valuation, so there is no single fixed figure for Montgomery County. We only publish fees confirmed by real homeowners — none have been reported here yet.
Confirm the current fee directly with Montgomery County Department of Permitting Services ((240) 777-0311). If you have paid for a permit here, you can add it here to help others.
Montgomery County Building Department
Office: Montgomery County Department of Permitting Services
Address: 2425 Reedie Dr 7th floor, Wheaton, MD 20902, USA
Phone: (240) 777-0311
Source: official Montgomery County government records. Hours and procedures can change — call ahead to confirm.
How to Apply in Montgomery County
In Montgomery County, you can begin your application online through the county's permit portal, or submit blueprints and a property survey in person. Including your contractor's Virginia Board for Contractors (DPOR) license number helps avoid rejections.
ADU Construction Requirements in Montgomery County
Typical Submittal Package
When applying for a ADU Construction permit, you or your contractor will generally need to submit the following documentation for the city's review:
- Comprehensive architectural and structural plans
- Foundation engineering reports
- Sewer, water, and utility connection plans
- Site plan showing property lines and setbacks
Standard Ordinances & Processing Time
Key code points for a ADU Construction in Montgomery County: ADUs typically have maximum square footage limits (often 800-1200 sq ft), height restrictions, and usually require dedicated off-street parking depending on local zoning.
Typical processing time: a few days to several weeks, depending on current workload and the season. Contact Montgomery County Department of Permitting Services for a current estimate.
Frequently Asked Questions
What happens if I build a ADU Construction without a permit in Montgomery County?
Building without authorization is considered a code violation. The local government can issue a Stop Work Order, forcing you to halt construction immediately. You may be subject to retroactive permit fees (often double the original cost), daily fines, or even a mandate to tear down the unpermitted work at your own expense.
Can a homeowner pull their own ADU Construction permit in Virginia?
Yes. Virginia generally allows property owners to act as their own general contractor under an Owner-Builder exemption. If you take this route, you assume full legal and financial liability and must ensure all work complies with the Virginia Uniform Statewide Building Code.
How much does a ADU Construction permit cost in Montgomery County?
Permit fees vary by jurisdiction and by your project's valuation, so Montgomery County does not publish a single fixed figure. Confirm the exact fee with the local building department before applying.
How long does it take to get a ADU Construction permit in Montgomery County?
Processing time in Montgomery County varies by season and current application volume at the building department; contact Montgomery County Department of Permitting Services for a current estimate.
Where do I apply for a ADU Construction permit in Montgomery County?
You can apply through the Montgomery County Department of Permitting Services or online via the county permit portal. For questions, call (240) 777-0311.
Help the Montgomery County Community
Did you recently pay for a permit here? Anonymously share the fee to help our database stay accurate.
Thank you! Your data has been saved.
Expert ADU Construction Resources
Legal & Compliance
HOA Approvals vs. City Permits: Which Comes First?
Understand the difference between municipal building permits and Homeowners Association approvals.
Read Guide
Permit Guides
The Ultimate Guide to US Building Permits in 2026
Everything you need to know about structural safety, legal compliance, and avoiding fines.
Read GuideBuilding It Yourself? Here's What You'll Need
Planning an ADU? Tools homeowners use in the design and layout phase:
📘
Backyard ADU Design Guide (Book)
View on Amazon →
📐
Laser Level
View on Amazon →
🔍
Franklin ProSensor Stud Finder
View on Amazon →
📏
25ft Tape Measure
View on Amazon →
As an Amazon Associate, we earn from qualifying purchases.
Other Permit Types in Montgomery County
Planning another home improvement project? Check the requirements and fees for:
Nearby Jurisdictions in Virginia
Building near the county line? Check requirements for neighboring areas: