Electrical, Mechanical & Plumbing

Electrical, Mechanical, and Plumbing permits are also required for residential work. In some cases, homeowners may secure a permit and do the work themselves. View more information on the Homeowner Electrician's Test.

Plumbers and Electricians performing work in the city are required to have their work inspected. Plumbers must hold a valid master plumber's license with this division. Electricians must hold a valid master electrician's license with the state. Heating and cooling contractors with a Mechanical permit may perform furnace and air conditioning work.

Apply for Residential Electrical, Mechanical or Plumbing Permit

Work Requiring a Permit

Electrical (excluding plugged appliances)

  • Heavy-up electrical service.
  • Adding new electrical fixtures and outlets.
  • Adding new electrical appliances.
  • Installing baseboard or other electric heating sources.
  • Installing exhaust fans and attic fans.


  • Installing or replacing a furnace.
  • Installing or replacing an air conditioning unit.
  • Adding, replacing or relocating ducts, diffusers or grilles.
  • Air conditioners, heat pumps, and emergency generators in single-unit detached residential zones must be accompanied by a house location survey, drawn to scale, showing the location of the unit and the distance from all property lines to ensure compliance with setbacks.


  • Adding, replacing or relocating plumbing fixtures.
  • Repairing or replacing water lines.
  • Repairing or replacing sewer lines.
  • Any changes in fixture piping.
  • Installation or replacement of water heaters.
 Still have questions? Contact: 

Permits and Inspections
111 Maryland Ave.
Rockville, MD 20850
Monday - Friday
8:00 a.m. - 4:30 p.m.