Residential Mechanical Permit
A mechanical permit is required to erect, install, enlarge, alter, repair, remove, convert or replace a mechanical heating, ventilating and air-conditioning system, the installation of which is regulated by the International Mechanical Code (IMC), International Fuel-Gas Code (IFGC) or the International Residential Code (IRC). This includes, but is not limited to: furnaces, heat pumps, air-conditioning units, range hoods, fuel-oil tanks and piping system, boilers with less than 350,000 BTU combined capacity, LP-gas tanks and piping systems from the first regulator transitioning to utilization pressure.
Apply for residential mechanical permits online. If plans or a Manual J calculation are required, that information must be submitted through the ePlans system. Visit our eServices page to learn more.
Email Electrical and Mechanical inquiries to:
DPS.Electrical-Mechanical@montgomerycountymd.gov.
A mechanical permit is required to erect, install, enlarge, alter, repair, remove, convert or replace a mechanical heating, ventilating and air-conditioning system, the installation of which is regulated by the International Mechanical Code (IMC), International Fuel-Gas Code (IFGC) or the International Residential Code (IRC), as appropriate.
Permits are not required for the following however, this does not exempt the work from compliance with any applicable code, laws or ordinances:
- Portable ventilation appliances and equipment
- Portable cooling units
- Steam, hot water, or chilled water piping within any heating or cooling equipment or appliances regulated by DPS
- Replacement of any minor part that does not alter the approval of equipment or an appliance or make such equipment or appliance unsafe
- Portable evaporative coolers
- Self-contained refrigeration systems with a maximum rating of 12,000 BTUs
- Finishing single-family basements (attached and detached) where the work is limited to ductwork and exhaust fans
- Replacemnt of components within a unit such as compressors and/or burners
Applications must be submitted electronically. Electronic applications for one-for-one replacements can be issued immediately, and those applications requiring plan review are generally issued within three business days.
Please see our fee schedule for information regarding fees associated with this process.
We have created a document to assist with identifying who can apply for mechanical permits based on the type of work being performed. Please click on the link below to see if you are permitted to apply for a mechanical permit. You can also contact DPS directly by using our staff directory located at the bottom of this page or by calling 240.777.0311.
Mechanical permits can be revised once issued by submitting a new/updated fully completed permit application. If changes are made to the location of the equipment or the duct loads, new site plans and new ACCA Manual J Calculations must be provided for approval.
If you are installing or replacing a gas furnace, DPS and WSSC must inspect the work. If the HVAC (heating, ventilation, and air conditioning) unit is all electric (heat pump), then just the DPS inspection is needed. For those units that require both inspections, it does not matter which inspection is done first.
Once issued the permit can be cancelled by submitting a written request from the property owner, home owner, or the mechanical contractor/company that applied for the permit only. Email written requests to DPS.Electrical-Mechanical@montgomerycountymd.gov.