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Mechanical Permits

When Do I Need a 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), as appropriate. These equipments include, but are not limited to furnaces, heat pumps, air-conditioning units, range hoods, cooling towers, chillers, fuel-oil tanks and piping system, boilers with less than 350,000 BTU combined capacity, LP-gas tanks and piping systems to the first regulator transitioning to utilization pressure.

 Permits shall not be required for the following:

 Portable heating appliances;

  1. Portable ventilation appliances and equipment;
  2. Portable cooling units;
  3. Steam, hot water or chilled water piping within any heating or cooling equipment or appliances regulated by this code;
  4. Replacement of any minor part that does not alter the approval of equipment or an appliance or make such equipment or appliance unsafe;
  5. Portable evaporative coolers;
  6. Self-contained refrigeration systems with a maximum output rating of 12,000 BTU.
  7. Finishing single-family detached and attached basements when the work is limited to ductwork and exhaust fans.
  8. Replacement of components within a unit such as compressors and burners.

Exemption from the permit requirements of this code shall not be deemed to grant authorization for work to be done in violation of the provisions of this code or other laws or ordinances of this jurisdiction.

Who Can Obtain a Mechanical Permit?

  1. Using the Application for Mechanical Permit, the following individuals/entities may apply for and obtain a mechanical permit:
    1. An individual licensed by the Maryland State Board of Heating, Ventilation, Air-Conditioning, and Refrigeration Contractors ( ) subject to the following limitations:
    2. Contractor with Limited license issued by the Board may exclusively maintain or repair one or more of the following: heating systems, cooling systems, refrigeration systems, ventilation systems, or hydronic systems.
    3. Contractor with a Master license may provide heating, ventilation, air-conditioning, or refrigeration services. ( This does not include installation of propane tanks or piping system, see item 13 below)
      Contractor with a Master restricted license may provide services in only one of the following areas:
      1. heating - forced air systems;
      2. heating - hydronic systems;
      3. ventilation;
      4. air-conditioning;
      5. or refrigeration
  2.  An individual owner of a single-family dwelling while that owner is practicing heating, ventilation, air-conditioning, or refrigeration services on or within a building or structure owned by the individual.
  3. An individual who is building a single-family dwelling in which that individual will reside while practicing heating, ventilation, air-conditioning, or refrigeration services on or within that dwelling.
  4. An employee of a public utility company regulated by the Public Service Commission, when engaged in:
    1. the development, construction, maintenance, or repair of electric or gas facilities located in the State; or
    2. the construction, maintenance, or repair of electric or gas appliances in the service area of the public utility.
  5. Subject to § 9A-403(a) of the Annotated Code of Maryland, an employee of the United States government, the State government, a local government, or an independent agency while that employee is practicing heating, ventilation, air-conditioning, or refrigeration services on or within buildings or structures owned or solely occupied by the United States government, the State government, a local government, or an independent agency.
  6. An individual employed in the installation, maintenance, alteration, repair, or replacement of self-contained appliances requiring not more than 225 volts or 25 amperes of electrical current.
  7. An individual possessing a master electrician's license issued by the State or any county, when engaged in the installation, alteration, service, repair, or replacement of individually controlled electric resistance heat.
  8. An individual possessing a master plumber's license issued by the State, Baltimore County, or the Washington Suburban Sanitary Commission when providing heating, ventilation, air-conditioning, or refrigeration services on hydronic heating systems.
  9. An individual possessing a license to practice engineering when providing heating, ventilation, air-conditioning, or refrigeration services in connection with the practice of engineering.
  10. An individual who installs, alters, remodels, maintains, or repairs oil burners exclusively while employed by a supplier of home heating fuel.
  11. An individual regularly employed by the owner of property, or the owner's agent, to engage in maintenance and repair work.
  12. An individual installing wood-burning prefabricated fireplaces or stoves.
    A state-licensed master plumber or a certified propane gas fitter when installing propane tanks and piping system. (A mechanical HVAC contractor is not authorized to install propane tanks and piping system)

Insurance Requirments

A holder of a master, master restricted, or limited heating, ventilation, air-conditioning, and refrigeration license may not contract to provide services on behalf of the licensee, or another person who provides heating, ventilation, air-conditioning, or refrigeration services, unless the work of the licensee, including completed operations, is covered by:

  1. general liability insurance in the amount of at least $300,000; and
  2. property damage insurance in the amount of at least $100,000.

Do I need Plans?

Generally plans are not required for detached and attached one-and two-family dwellings.  If you are installing an outside generalor, however, you will need to bring a copy of your house location survey (also called a site-plan) so that zoning may review the setbacks of your equipment.  Plans for multi-family buildings and commercial buildings must be prepared by a registered professional engineer licensed in the State of Maryland and shall be submitted at the time of the building permit application.

What is the Application Process?

Anyone mentioned in the previous section “Who Can Obtain a Mechanical Permit?” may apply in person or by mail.

The application(s) will be checked for the following:

  • Completeness
  • Valid and current business and master's license numbers
    Up-to-date insurance certificate
  • Outstanding Notices of Violation for the premises (outstanding fines will be collected with the permit fee)
  • Building permit (if required for the work being done), issued prior to the mechanical permit application
  • Separate applications for NEW and REPLACEMENT equipment
  • Signature of HVAC master

If all conditions are met:

  • Fess are calculated and collected.
  • A receipt is issued.
  • A permit number is assigned.
  • The permit is issued while the customer waits.

Certification of modified drawings. (Click here)

Plan submittal changes which result from the suspension of a plan review must include a "Certification Of Modified Drawings". The design professional(s) responsible for the design of the project shall review all the changes from each of the disciplines and certify that the resubmitted design documents prepared under their license did, or did not, require modification as a result of any changes made.

How Much Does a Permit Cost?

Permit fees are assessed in accordance with Executive Regulation No. 5-11AMIII, Schedule of Fees for Permits, Licenses and Certifications.

Do I Need a Seperate Electrical Permit?

An electrical permit for mechanical equipment and appliance installation is required when new high voltage branch circuit conductors or feeder circuit conductors are installed. An electrical permit is not required to hook-up appliances to existing conductors and to add/replace disconnect switches.

Electrical permits will not be required for low voltage control wiring except when such circuits penetrate fire-rated assemblies, or are installed in an air plenums; provided the voltage does not exceed 30 volts. 

Application Package
Application for Mechanical Permit Application
Fees and Taxes
Fee Schedules Executive Regulations for Fees
Credit Card Authorization Form Credit Card Authorization Form
None at This Time General Bond Information
Codes, Standards, Executive Regulations
 Montgomery County Code ICC International Mechanical Code /2009
 Energy Code 2015 International Energy Conservation Code
Guidelines, Memorandum of Understandings, Interpretations

Minimum Information Required for Review of Mechanical Drawings of Commercial Buildings

Minimum Information Required for Review of Mechanical Drawings of Commercial Buildings

Inspection Requirements
  Commercial Mechanical Inspections
  Residential Inspections
Certification for Refrigerant, Hydronic and Fuel Oil Piping Mechanical Inspection Certification
Certification for LP Gas Installations Mechanical Inspection Certification for LP Gas Systems
Frequently Asked Questions
311 Web Portal: Enter key word "Mechanical"
Online Permitting Status Information and Inspections
Online Data Search Search DPS
Call for More Information
In Montgomery County 311
Outside of Montgomery County 240-777-0311
Other Agencies to Contact
Other Agencies and Utilities to Contact Allegheny Power
  American Institute of Architects (AIA)
  American National Standards Institute (ANSI)
  American Society of Heating, Refrigerating & Air Conditioning Engineers (ASHRAE)
  Baltimore Gas & Electric Co. (BG&E)
  Board of Appeals
  Historical Preservation
  International Code Council (ICC)
  Maryland Department of Assessments and Taxation
  Maryland Department of the Environment
  Maryland Division of State Documents
  Masonry Institute of America (MIA)
  Miss Utility
  National Glass Association (NGA)
  MNCPPC: Historic Area Work Permits
  MNCPPC: MC Atlas
  MNCPPC: Zoning
  National Fire Protection Association (NFPA)
  Potomac Electric Power Company (PEPCO)
  U.S. Department of Energy (DOE) by Pacific Northwest National Laboratory (PNNL)
  Washington Gas Light Co.