2.2 Permits, Inspections, Approvals & Violations
Key Takeaways
- 2024 IMC 105.1 requires a permit before erecting, installing, enlarging, altering, repairing, removing, converting, or replacing a regulated mechanical system, except emergency replacements filed the next working business day.
- IMC 105.2 lists eight model-code permit exemptions (portables, in-unit hydronic piping, minor parts, ≤10 lb or ≤1 hp self-contained refrigeration, unconnected portable fuel cells); exemption is not permission to violate the code.
- IMC 111.2 requires underground inspection before backfill, rough-in before wall or ceiling membranes, and final upon completion; the permit holder must request inspections and keep work visible until approved.
- Replacement heating equipment serving an occupied portion may operate if inspection is requested not more than 48 hours after completion and before concealment (111.2).
- A 2024 IMC 115 stop-work order is written, names the reason and the conditions to resume, and requires the cited work to cease immediately; emergency stops need not be written first.
When a mechanical permit is required
2024 IMC 105.1 is the default: an owner, owner’s authorized agent, or contractor who wants to erect, install, enlarge, alter, repair, remove, convert, or replace a mechanical system regulated by the code, or to cause that work, shall first apply and obtain the required permit. That list includes replacements. A “like-for-like” rooftop unit is still a replacement of a regulated system. The only model-code exception in 105.1 is an emergency replacement or repair: the permit application is due the next working business day of the department of mechanical inspection. IFGC 105.1 is the same idea for gas installations, with the same next-working-day emergency filing.
IMC 105.1.1 lets the code official issue an annual permit instead of a separate permit for each alteration to an already approved system, but only to a person, firm, or corporation that regularly employs qualified tradespersons in a building the applicant owns or operates. The annual-permit holder must keep a detailed alteration record and give the official access to it (105.1.2). That is a facilities-maintenance tool, not a way for a tenant improvement contractor to skip plan review on a new kitchen.
Model-code work that does not need a permit
2024 IMC 105.2 is the exemption list you should be able to recite. Permits are not required for portable heating appliances; portable ventilation appliances and equipment; portable cooling units; steam, hot-water, or chilled-water piping within heating or cooling equipment or appliances the code already regulates; replacement of a minor part that does not alter the equipment’s approval or make it unsafe; portable evaporative coolers; self-contained refrigeration systems that contain 10 pounds (4.5 kg) or less of refrigerant or that are actuated by motors of 1 horsepower (0.75 kW) or less; and portable fuel-cell appliances that are not connected to a fixed piping system and are not interconnected to a power grid. The last sentence of 105.2 is the exam sting: exemption from the permit is not authorization to violate the IMC or any other law. A portable heater still cannot sit in a prohibited location; an exempt refrigerator still cannot dump refrigerant into a plenum.
The 2024 IFGC exemption list is shorter. IFGC 105.2 excuses portable heating appliances and replacement of a minor component that does not alter approval or make the appliance or equipment unsafe. Gas piping, new gas appliances, and venting are not on that short list. If a jurisdiction amends either list, you inspect the amendment. Do not memorize a city’s flyer as if it were the model code, and do not enforce the model list against a local ordinance that closed the portable-equipment hole.
| Administrative clock (2024 IMC) | Published rule |
|---|---|
| Permit application | Deemed abandoned 180 days after filing unless pursued in good faith or a permit is issued; written extensions not exceeding 180 days each (105.3.2) |
| Permit start / inactivity | Expires if work does not start within 180 days, or if work is suspended or abandoned for 180 days after start (105.4.3) |
| Restart after lapse | New permit required; fee is one-half of a new-permit fee if the documents are unchanged and abandonment has not exceeded 1 year (105.4.3) |
| Unexpired-permit extension | One extension, not more than 180 days, for good cause; fee one-half of a new-permit fee (105.4.4) |
| Temporary uses, equipment, systems | Time of service limited; not more than 180 days, with extensions for demonstrated cause (110.1) |
| Occupied heating replacement | Inspection request filed not more than 48 hours after the replacement is complete, and before concealment (111.2) |
Application, issuance, and what a permit is not
The application is filed on the official’s form, with the fee, a general description, the location, the owner’s or agent’s signature, and the proposed occupancy (105.3). The official may inspect before issuing (105.3.1). Issuance happens only after the official finds that the proposed work conforms to the IMC and other applicable laws and that the Section 108 fees are paid (105.4). A permit is not valid until those fees are paid (108.1). Starting work before the permit is issued triggers an additional fee the official establishes (108.4) — and it is still a violation under 114.1.
When construction documents are required, issuance includes endorsing and stamping those documents APPROVED (105.4.1). Work shall be done in accordance with those approved documents, and they shall not be changed without the official’s authorization. The official may issue a partial permit for part of a mechanical system before the entire set is approved, if enough information is on file; the holder proceeds at the holder’s own risk with no promise that the rest of the system will be permitted. IMC 105.4.2 then strips the magic from the stamp: issuance is not approval of a violation, a permit that pretends to cancel the code is invalid, and the official may still require correction of errors in the documents. Post the permit (or a copy) on site until the project is complete (105.4.7). Suspend or revoke a permit issued in error or on bad information (105.4.5).
Required inspections and who calls them
Construction that needs a permit is subject to inspection and must remain visible and accessible until it is approved (111.1). An inspection approval is not a license to violate the code; an inspection that pretends to cancel the code is not valid. The permit holder — not the inspector — is responsible for scheduling (111.2). It is the holder’s or agent’s duty to notify the official when work is ready and to provide access and means for the inspection (111.2.2). Work shall not go beyond each successive inspection point without approval; failing work shall be corrected and shall not be covered or concealed until the official authorizes it (111.2.3).
2024 IMC 111.2 lists three required inspections, plus “other such inspections as necessary”:
- Underground — after trenches or ditches are excavated and bedded and piping is installed, and before backfill. If the excavated soil is rocky, rubble-filled, frozen, or otherwise likely to break or corrode the pipe, clean backfill must be on site. Ground-source heat-pump loops tested under IMC 1210.10 may be backfilled before inspection.
- Rough-in — after the roof, framing, fireblocking, and bracing are in place and all ducting and other components that will be concealed are complete, and before wall or ceiling membranes. That is the model-code home of “above-ceiling” work: once tiles, gypsum, or other membranes go up, the rough-in window has closed.
- Final — upon completion of the mechanical system.
Many jurisdictions split an extra above-ceiling inspection after hangers, fire dampers, and flex are in and before lay-in tile. IMC 111.2.1 already authorizes those extra inspections. Teach the three published hold points for the exam; enforce the adopted extra hold point in the field. Tests required by the code are made by the permit holder and observed by the official (111.3). New systems and altered, extended, renovated, or repaired parts are tested to disclose leaks and defects (111.3.1). The holder furnishes apparatus, material, and labor (111.3.2). Failed work is corrected and resubmitted (111.3.3).
Replacement heating equipment serving an occupied portion of a structure may operate before the inspections above are complete, but only if a request for inspection is filed not more than 48 hours after the replacement is finished and before any permanent concealment (111.2). That is a narrow occupied-building relief valve, not a general “swap it Friday, call us next month” rule.
Temporary equipment, utilities, and closeout
Temporary uses, equipment, and systems need a permit limited in time of service and not permitted for more than 180 days, with extensions for demonstrated cause (110.1). They must still conform as necessary to protect health, safety, and welfare (110.2). The official may terminate the temporary approval (110.4). No one may connect a utility, energy, fuel, or power source to a regulated building or system that required a permit until the official authorizes the connection (109.1). Temporary utility connections for testing or temporary approval are the official’s call (109.2). The official may authorize disconnection in an emergency to remove an immediate life or property hazard, or where a connection was made without the required approval, with notice to the utility and, wherever possible, to the owner and occupant (109.3).
The IMC closeout document is a notice of approval, issued after the prescribed tests and inspections show the work complies in all respects (107.1). The official may suspend or revoke that notice in writing if it was issued in error, on incorrect information, or if the premises violate the code (107.2). A certificate of occupancy is not an IMC form. Occupancy certificates live in the building code. Mechanical approval is typically a prerequisite the building official needs before signing a C of O, but passing a mechanical final is not itself a certificate of occupancy. Do not tell an owner they may occupy because you signed a mechanical card.
Violations, stop-work, and two field pictures
It is unlawful to erect, construct, alter, repair, remove, demolish, or use a mechanical system in conflict with the IMC (114.1). The official serves a notice of violation or order on the person responsible, directing that the illegal action stop and the violation be abated (114.2). If the notice is ignored, counsel for the jurisdiction is asked to restrain, correct, or abate (114.3). Penalty amounts are left as local fill-ins in the model code — do not invent a fine. Each day a violation continues after notice is a separate offense (114.4).
A stop work order is the immediate tool. Where work is contrary to the code or is dangerous or unsafe, the official may issue one (115.1). It shall be in writing and given to the owner, the owner’s authorized agent, or the person doing the work. Cited work shall immediately cease. The order states the reason and the conditions under which the work may resume (115.2). In an emergency, written notice is not required before stopping the work (115.3). Continuing work after a stop-work order, except work the order directs in order to remove the violation or unsafe condition, is a finable act (115.4).
Picture two jobs. Job A is a rooftop unit swap on an occupied office: same capacity, same curb, listed replacement, manufacturer’s instructions on the roof. A permit is still required (105.1). If it is a true emergency after a Friday-night compressor failure, file the application the next working business day. The new unit may heat the occupied floors if inspection is requested within 48 hours and nothing is concealed. You check listing, clearances, condensate, gas or electric connections, and the approved documents or an approved like-for-like scope. Job B is a new Type I hood over a new charbroiler. That is not a minor part and not a portable appliance. It needs construction documents (hood, grease duct, makeup air, suppression interface), a permit, underground work if grease duct or gas is buried, rough-in before concealment of the grease duct and fire-rated enclosure, and a final that includes the required tests. Treating Job B like Job A is how grease ducts get buried uninspected and how stop-work orders get written.
Under 2024 IMC 105.1, who must obtain a mechanical permit and when?
What required mechanical inspections does 2024 IMC 111.2 list, and when are they made?
A crew is welding a grease duct that does not match the approved drawings. How must a 2024 IMC stop-work order operate?