County Building Permits

St. Mary's County, MD - 2026 Building Permit Guide

How to apply for a building permit in unincorporated St. Mary's County, Maryland. Permit authority, application steps, fees, and inspection requirements.

Maryland Updated March 2026

Permit Authority

The LUGM Permits Division is the central intake and coordination point for all building activity in unincorporated St. Mary's County, including Lexington Park, California, Mechanicsville, Great Mills, Hollywood, and all other unincorporated areas. Lexington Park falls within the Lexington Park Development District (LPDD), which imposes additional design and site-plan standards for commercial and multi-family development.

Department
St. Mary's County Department of Land Use and Growth Management (LUGM), Permits Division
Address
23150 Leonard Hall Drive, Leonardtown, MD 20650
Phone
301-475-4200 ext. 1500; Inspections: 301-475-4200 ext. 1580
Website
https://www.stmaryscountymd.gov/LUGM/Permits/

Online Permit Portal

Open eTRAKiT

Platform: eTRAKiT • Account required: Yes • Submission: Online or in-person

Application Process

  1. For On Demand track (simple residential projects): Confirm project qualifies (detached sheds/garages/carports, attached garages/carports/breezeways, open or screened porches, decks, renovations with MetCom public water/sewer connection).
  2. Visit permit counter during hours: Monday and Thursday 8:30 AM to 2:00 PM; Tuesday, Wednesday, Friday 8:30 AM to 4:30 PM.
  3. Submit completed signed permit application, owner authorization if applicant is not owner, 3 copies of scaled plot plan, and $20 application fee.
  4. County staff reviews; if project is outside Critical Area and does not trigger other agency review, issuance may occur same day.
  5. Pick up permit, receive placard for on-site posting, and pay all agency fees.
  6. Schedule building inspections through MDIA or eTRAKiT portal.
  7. For Drop Off track (larger/complex projects): Prepare required documents including completed permit application, owner authorization, 3 printed scaled plot/site plans, digital floor plan emailed to BPService@stmaryscountymd.gov, and project-specific materials.
  8. Drop off or submit digitally; incomplete submissions are returned.
  9. County coordinates multi-agency review (Health Department, MetCom, Soil Conservation, State Fire Marshal, DPW&T, Maryland Department of the Environment).
  10. Monitor permit status online; respond to any agency comments and resubmit revisions.
  11. After all approvals and fees paid, pick up permit and placard.
  12. For Commercial/Non-Residential: Most commercial projects require site plan approval before building permit issuance. File Concept Site Plan with LUGM ($920 plus $20 application fee), obtain TEC multi-agency review, present to Planning Commission for concept approval.
  13. After concept approval, submit final site plan to LUGM and TEC agencies (Major Site Plan: $1,500 per disturbed acre plus $20 application fee).
  14. After site plan approval, submit commercial building permit application with floor plans and digital submittal. State Fire Marshal plan review required.
  15. Pay all agency fees at permit issuance and post placard on site.
  16. Schedule commercial building inspections with LUGM Inspections Division.

Typical processing time: On Demand residential: same day for qualifying simple projects outside Critical Area. Drop Off residential new dwellings: approximately 30 to 60 days. Critical Area projects: approximately 60 to 90 days. Commercial: depends on site plan complexity and agency review.

Source: St. Mary's County Department of Land Use and Growth Management (LUGM), Permits Division

General Requirements

A building permit is required for new construction, additions, alterations, demolition, pools, decks, piers/bulkheads/revetments, land clearing, and trade-system changes. Residential examples: new single-family dwellings, modular and mobile homes, additions adding living space, accessory apartments, detached garages, carports, sheds (over 600 sq. ft. under 2024 code amendment), decks and open/screened porches, in-ground pools, and renovations. Commercial examples: new buildings, additions, changes of occupancy, interior alterations requiring structural work, signs, and demolition.

Required Documents

  • Completed permit application
  • Owner authorization (if applicant is not owner)
  • Scaled plot plan (3 printed copies for residential)
  • Digital floor plan (emailed to BPService@stmaryscountymd.gov)
  • Application fee
  • Project-specific supporting materials (septic/perc data, engineering, Critical Area site plan, etc.)
  • Site plan (for commercial projects)
  • Quality site plan (for Critical Area projects)
  • State Fire Marshal plan review materials (for commercial projects)
Permit validity
A permit application is deemed abandoned 12 months after filing unless actively pursued or permit is issued; one extension of up to 12 additional months may be granted in writing. An issued building permit is valid for 24 months from issuance and may be renewed. A separate zoning permit expires if work is not commenced within 12 months or is suspended/abandoned for 12 months; one extension of up to 12 additional months may be granted for good cause.
Building code
2021 International Building Code; 2021 International Residential Code; 2021 International Energy Conservation Code; 2021 International Existing Building Code; 2021 International Swimming Pool and Spa Code; 2018 International Fuel Gas Code (pending Maryland adoption); 2018 International Mechanical Code (pending Maryland adoption); 2023 National Electrical Code. All effective under County Chapter 203 adopted July 15, 2024.
Owner-builder
The 2026 residential permit application includes a 'Who will complete the construction?' field with options for 'Contractor' or 'Myself,' confirming that owner self-performance is allowed. For electrical work, owners must separately obtain a homeowner electrical permit through the county's Board of Electrical Examiners, which requires passing a written exam offered twice a year (January and July); applicants need driver's license, copy of building permit, copy of deed, and $25 fee. Homeowner electrical permits do not cover service upgrades or solar installations.
Contractor requirements
Home improvement contractors must hold a Maryland Home Improvement Commission (MHIC) license for home improvement work over $100. Prime contractor is responsible for obtaining permits and permits issued to MHIC contractors must include contractor's license number. Electrical work requires active Maryland electrician license. MHIC does not authorize electrical, HVACR, or plumbing work; separate trade licensing applies.

Fees

Payment note
The fee FAQ documents are dated 2023 and a July 1, 2025 fee schedule update has been referenced but a comprehensive updated standalone fee PDF was not identified during research. Applicants should confirm current fees with LUGM at permit counter hours.

Fees change. Verify current amounts at the official fee schedule (effective August 24, 2023 (residential); July 1, 2025 (development review fees)).

Work That Does NOT Require a Permit

  • One-story detached accessory structures up to 600 square feet (exempt from building permit requirement under county's 2024 local building code amendment R105.2)
  • Above-ground storable or portable pools under 24 inches in depth
  • Ordinary maintenance and repair that does not involve structural changes
  • Painting and wallpaper (no trade permit triggered for paint)

Important: All otherwise-exempt work still requires county authorization if located in the Chesapeake Bay Critical Area and involves vegetation removal, land disturbance, added impervious surface, or new land use. Grading exceeding 1,000 cubic yards triggers separate DPW&T grading permit regardless of building permit exemption status. Applicants should confirm current rules with LUGM before proceeding without a permit for any detached accessory structure.

Inspections

How to Schedule

Scheduling deadline
Inspection requests received by 6:00 a.m. are scheduled for next business day. DPW&T site-development inspections use 48-hour response window.
Inspection hours
Permit counter hours: Monday and Thursday 8:30 AM to 2:00 PM; Tuesday, Wednesday, Friday 8:30 AM to 4:30 PM. General office hours: Monday through Friday 8:00 AM to 5:00 PM.

Typical inspection sequence: Residential Stage 1: footing, foundation wall, backfill, slab, and floodplain elevation documentation if applicable. Stage 2: rough plumbing/mechanical/gas/electrical, followed by framing/masonry, followed by fire-resistance-rated construction if required. Stage 3: tie-down and energy. Final inspection: after all permitted work complete and before occupancy. Prerequisites before final: E-911 address must be installed; elevation documentation must be on file if in flood hazard area. Commercial COs require all agency sign-offs from site plan review plus verification of third-party building code inspections and zoning inspection staff confirmation.

Additional Resources

Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the St. Mary's County Department of Land Use and Growth Management (LUGM), Permits Division before applying.

Frequently Asked Questions

St. Mary's County Building Permit FAQ

Do I need a building permit in unincorporated St. Mary's County, MD?
A building permit is required for new construction, additions, alterations, demolition, pools, decks, piers/bulkheads/revetments, land clearing, and trade-system changes. Residential examples: new single-family dwellings, modular and mobile homes, additions adding living space, accessory apartments, detached garages, carports, sheds (over 600 sq. ft. under 2024 code amendment), decks and open/screened porches, in-ground pools, and renovations. Commercial examples: new buildings, additions, changes of occupancy, interior alterations requiring structural work, signs, and demolition.
How do I apply for a building permit in unincorporated St. Mary's County, MD?
1. For On Demand track (simple residential projects): Confirm project qualifies (detached sheds/garages/carports, attached garages/carports/breezeways, open or screened porches, decks, renovations with MetCom public water/sewer connection). 2. Visit permit counter during hours: Monday and Thursday 8:30 AM to 2:00 PM; Tuesday, Wednesday, Friday 8:30 AM to 4:30 PM. 3. Submit completed signed permit application, owner authorization if applicant is not owner, 3 copies of scaled plot plan, and $20 application fee. 4. County staff reviews; if project is outside Critical Area and does not trigger other agency review, issuance may occur same day. 5. Pick up permit, receive placard for on-site posting, and pay all agency fees. 6. Schedule building inspections through MDIA or eTRAKiT portal. 7. For Drop Off track (larger/complex projects): Prepare required documents including completed permit application, owner authorization, 3 printed scaled plot/site plans, digital floor plan emailed to BPService@stmaryscountymd.gov, and project-specific materials. 8. Drop off or submit digitally; incomplete submissions are returned. 9. County coordinates multi-agency review (Health Department, MetCom, Soil Conservation, State Fire Marshal, DPW&T, Maryland Department of the Environment). 10. Monitor permit status online; respond to any agency comments and resubmit revisions. 11. After all approvals and fees paid, pick up permit and placard. 12. For Commercial/Non-Residential: Most commercial projects require site plan approval before building permit issuance. File Concept Site Plan with LUGM ($920 plus $20 application fee), obtain TEC multi-agency review, present to Planning Commission for concept approval. 13. After concept approval, submit final site plan to LUGM and TEC agencies (Major Site Plan: $1,500 per disturbed acre plus $20 application fee). 14. After site plan approval, submit commercial building permit application with floor plans and digital submittal. State Fire Marshal plan review required. 15. Pay all agency fees at permit issuance and post placard on site. 16. Schedule commercial building inspections with LUGM Inspections Division.
How long does it take to get a building permit in unincorporated St. Mary's County, MD?
Typical processing time is On Demand residential: same day for qualifying simple projects outside Critical Area. Drop Off residential new dwellings: approximately 30 to 60 days. Critical Area projects: approximately 60 to 90 days. Commercial: depends on site plan complexity and agency review..
What work is exempt from building permits in unincorporated St. Mary's County, MD?
The following work is generally exempt: One-story detached accessory structures up to 600 square feet (exempt from building permit requirement under county's 2024 local building code amendment R105.2); Above-ground storable or portable pools under 24 inches in depth; Ordinary maintenance and repair that does not involve structural changes; Painting and wallpaper (no trade permit triggered for paint). Note: All otherwise-exempt work still requires county authorization if located in the Chesapeake Bay Critical Area and involves vegetation removal, land disturbance, added impervious surface, or new land use. Grading exceeding 1,000 cubic yards triggers separate DPW&T grading permit regardless of building permit exemption status. Applicants should confirm current rules with LUGM before proceeding without a permit for any detached accessory structure.
How do I schedule a building inspection in unincorporated St. Mary's County, MD?
Inspections can be scheduled via: LUGM Inspections 301-475-4200 ext. 1580, MDIA (Middle Department Inspection Agency) 301-884-4547, eTRAKiT portal, DPW&T site-development inspection request form. Inspection requests received by 6:00 a.m. are scheduled for next business day. DPW&T site-development inspections use 48-hour response window..

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Important: This page is an educational resource provided by jaspector.com. It is not legal advice, and it does not substitute for official guidance from the permit authority listed above. Permit requirements, fees, and processes change frequently. Always verify current requirements directly with the issuing department before beginning any construction project. Use of this page does not create an attorney-client relationship. Jaspector assumes no liability for any outcomes arising from reliance on this information.
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