Residential Additions and Alterations

Residential additions add square footage to the residential structure, not including condominiums. Screened porches are considered residential additions.

Residential alterations change the use of existing square footage, not including condominiums.

  1. Permits
  2. Additional Considerations
  3.  Fees
  4.  Inspections

Required Permits

  • A building permit application, signed by the property owner. 
    • Square feet of area being disturbed (required)
    • If your property is located in an incorporated town within Loudoun County, submit an approved zoning permit from the town with your application.

Additional Documentation

In addition to the permit application, you are required to submit:

  • Plat of property (required for additions only) showing:
  • Building plans: all structural elements must be completely detailed and included on a comprehensive set of plans. 
  • Residential trade permits (electrical, gas, mechanical, plumbing)
  • Health department approval will also be required if a bedroom is being added for a dwelling served by well and septic.

Learn who should apply for permits.

Submit an application

  • Submit the completed permit application and required documentation in one of the following ways: 
    • Online in LandMARC (Account Required)
    • In person (paper submission): Building and Development
      Loudoun County Government Center
      1 Harrison Street, SE.
      Leesburg, Virginia 20175
      Hours: Monday through Friday, 8:30 a.m. to 5 p.m.
      • Paper submissions require three sets of building plans and the house location plat for additions.


Call Building and Development at 703-777-0220, option 1.