Montgomery County MD Basement Permit & Inspection Guide

Thinking about turning that under-used basement in Montgomery County, Maryland into livable space? Before the first stud goes up, you’ll need the right permits and a clear plan for inspections. Montgomery County’s Department of Permitting Services (DPS) and the Washington Suburban Sanitary Commission (WSSC) work together to enforce some of the strictest residential codes in the state. Skipping a step can mean stop-work orders, re-inspection fees, or tearing out brand-new finishes. Use this guide to move from application to final approval—without surprises.

Permits Required for Basement Projects in Montgomery County

Any basement finish or remodel here typically triggers five possible permits:

Permit Type	When It’s Required	Issuing Agency
Building	All structural work—framing new walls, altering layout, cutting an egress window, or changing ceiling height	Montgomery County DPS
Electrical	New circuits, lighting, outlets, service-panel changes	Montgomery County DPS
Fire Protection	Only if the home already has a sprinkler system; separate sprinkler permit required	Fire Marshal Office
Mechanical	Even small HVAC scope counts. Adding returns, relocating ducts, or replacing equipment all need a mechanical permit	Montgomery County DPS
WSSC Plumbing	Any new bathroom, bar sink, drain relocation, or gas line work is permitted and inspected by WSSC, not DPS	WSSC ePermitting

Getting each permit up front keeps your project on schedule and avoids “surprise” trade permits later.

Licenses Required to Pull Montgomery County Permits

Montgomery County follows the same Maryland rules as our other service areas: only properly licensed contractors can apply for permits on your behalf .

• Building: Maryland Home Improvement Contractor (MHIC) License
  Required for general building and structural work. Search or verify contractors through the MD License Search Tool.
  
  
• Electrical: Maryland Master Electrician License
  Either a state-issued or Montgomery County-recognized Master Electrician license is needed for any electrical permit.
  
  
• Mechanical: Maryland Master HVACR Contractor License
  Required for all HVAC system installation, relocation, or major modification work.
  
  
• Plumbing: Maryland Master Plumber License (WSSC-registered)
  All plumbing contractors must be licensed through the State of Maryland and registered with WSSC’s online licensing system.
  
  
• Fire Protection: Maryland Fire-Sprinkler Contractor License
  Required to modify or install any part of a fire sprinkler system, even if only in the basement.

Hiring licensed pros protects you, keeps insurance valid, and satisfies DPS/WSSC requirements.

Inspection Requirements in Montgomery County

Expect 7 – 12 separate inspections from rough-in to finals. Key sequencing rules:

Special Case: WSSC Plumbing Permits

For all Montgomery county projects WSSC (Washington Suburban Sanitary Commission) handles plumbing permits instead of the county office. If this applies to your project:

• You must first pass WSSC close-in and final inspections.
• Only after WSSC sign-off can you schedule Montgomery county  Electrical, Mechanical, Fire Protection, and Building close-in or final inspections.

General Inspection Sequence:

• WSSC Plumbing groundwork inspections must be completed before closing up the slab or subfloor. If the project calls for new drains or a bathroom rough-in, WSSC must inspect and pass the underground piping before the slab is poured or patched. Skipping this step forces you to jack-hammer the floor later.
  
  
• WSSC Plumbing close-in inspection must be passed before other trade inspections.
  
  
• Fire protection inspection Rough-in inspection by the Fire Marshall must be performed before scheduling close-in building inspection.

• Close-in Inspections (Electrical, Mechanical and Building)

Once each trade completes their part is, but before insulation, schedule the individual trade rough-in inspections. Montgomery County DPS allows you to group Electrical, Mechanical and Building Close-in into a single “combo close-in” visit. 

• Insulation inspection is required before drywall can be installed. With framing approved, install insulation and book this quick check.
  
  
• WSSC Plumbing final inspection must be passed before other final trade inspections.
  
  
• Final sprinkler hydro-test Inspection by the Fire Marshall must be performed before scheduling close-in building inspection.

• Final Inspections (Electrical, Mechanical, Building). Each trade returns to prove fixtures, devices and equipment are operating safely. DPS lets you book a “combo final” for Electrical + Mechanical + Building if all three trades are ready together, saving a trip, but only after the Final sprinkler hydro-test (where applicable) has passed

• Final Building inspection must be passed before occupancy or use. The DPS building inspector confirms handrails, emergency egress, smoke/CO alarms, door clearances and finish materials. All trade finals must be closed before this visit can be scheduled. Passed? Your permit is officially closed and the basement is legal living space.
  
  

Scheduling tip: WSSC and DPS send different inspectors, and Montgomery County lets you pick dates independently—handy if one trade lags behind.

Why Trust BasementRemodeling.com With Your Montgomery County Project?

No other remodeler in Maryland has pulled—and passed—more basement permits than we have. Our in-house permitting team:

• Preps DPS & WSSC applications and plan sets
  
  
• Coordinates combo inspections to minimize site visits
  
  
• Works exclusively with MHIC, Master Electricians, Master HVAC, and WSSC-licensed plumbers
  
  
• Delivers code-compliant basements that appraise higher and insure easier
  
  

Browse our Montgomery County portfolio or request a free quote to see what’s possible.

What Happens If You Finish a Basement Without Permits?

DPS inspectors issue immediate Stop-Work Orders when unpermitted construction is discovered. Best-case, you’ll pay double permit fees and wait for retroactive plan review; worst-case, framing, drywall, or even plumbing gets ripped out for inspection access—on your dime. Unpermitted work can also:

• Void homeowners-insurance claims
  
  
• Complicate appraisals or home sales
  
  
• Mask life-safety hazards (electrical fires, CO leaks, structural failure)
  
  

Permits aren’t paperwork - they’re protection.

We Proudly Serve These Montgomery County Communities

Ashton,  Sandy Spring,  Bethesda,  Brookeville,  Burtonsville,  Cabin John,  Chevy Chase,  Cloverly,  Colesville,  Damascus,  Darnestown,  Derwood,  Fairland,  Gaithersburg,  Germantown,  Glen Echo,  Kensington,  Laytonsville,  Montgomery Village,  North Bethesda,  North Potomac,  Olney,  Poolesville,  Potomac,  Rockville,  Silver Spring,  Spencerville,  Takoma Park,  Travilah,  Washington Grove,  Wheaton,  White Oak

Plus every unincorporated ZIP in between. View more projects in our statewide portfolio and other county-specific permit guides on our Permits and Inspections blog section.

Ready to Finish Your Basement the Right Way?

Let BasementRemodeling.com handle permits, inspections, and construction from start to finish - so you can enjoy a beautiful, code-compliant new living space without the stress. Get started today.