Selecting the wrong HVAC subcontractor on a commercial project creates problems that follow you through construction and past occupancy. Missed inspections, equipment ordered too late, coordination failures with other trades — they all trace back to qualification decisions made before the subcontract was signed.
Here's what to look for, verify, and ask when you're evaluating commercial HVAC subs for work in the St. Louis market.
Licensing: St. Louis Is Not Uniform
Missouri does not issue a single statewide mechanical contractor license. Licensing for HVAC and mechanical work is managed at the local jurisdiction level — which means a contractor licensed in St. Charles County may not be authorized to pull permits in the City of St. Louis, and vice versa.
Before you issue a subcontract, confirm that your HVAC sub holds the specific mechanical license for the jurisdiction where the project is located. The four primary jurisdictions for commercial work in the metro area are:
- City of St. Louis
- St. Louis County
- St. Charles County
- Jefferson County
A sub that needs to go get licensed mid-project is a sub that will cause permit delays. Verify this before you negotiate anything else.
Insurance: Verify the Certificate, Not the Promise
Commercial projects typically require general liability coverage — often $1M to $2M per occurrence — as a minimum for subcontractors. Workers' comp is required if they have employees.
Don't accept a verbal assurance or a PDF of an old certificate. Request a current certificate of insurance directly from the contractor's insurance provider, naming your company as the certificate holder. Verify that it covers the project duration and that it hasn't lapsed.
What to ask for
- • Current certificate of insurance showing GL coverage limits
- • Workers' compensation documentation (if applicable)
- • Your company named as certificate holder
- • Coverage dates that span the full project timeline
Questions to Ask During Qualification
A compliant license and insurance certificate get a sub in the door. These questions help you evaluate whether they'll actually perform on your project.
HVAC work on a new multifamily development looks different from a retail build-out or a strip mall RTU replacement. A sub that primarily does tenant improvements may not have the coordination experience for a ground-up commercial build, and vice versa.
Permit timelines in St. Louis County and the City of St. Louis can vary. A sub should be able to tell you their process for permit submission, rough-in inspections, and final sign-off — and they should own that process without you having to manage it.
Equipment availability has been inconsistent across the industry. Ask about lead times for the specific equipment the project requires — RTUs, air handlers, split systems — and get a clear answer on when they need to order to stay on schedule.
Some smaller contractors take on more work than their capacity supports. Know who your point of contact is, whether they will be on-site regularly, and how many crews they can commit to your project schedule.
What a Well-Structured HVAC Bid Should Include
A vague scope in a bid package is a change order waiting to happen. When you receive a commercial HVAC bid, the proposal should clearly define what is and is not included.
What should be in scope
- Equipment supply and installation (make, model, and capacity specified)
- Ductwork fabrication and installation
- Refrigerant line sets (if applicable)
- Electrical connections from the disconnect (or clearly noted as NIC)
- Thermostat or controls (specify type and programming scope)
- Permit fees and inspections
- Startup and commissioning
- Warranty on labor and equipment
Common exclusions to clarify upfront
- Electrical service and panel work (typically by the electrical sub)
- Gas line rough-in to the equipment (often by the plumber)
- Structural support or roof curbs (clarify who provides and who installs)
- Building automation system (BAS) integration beyond basic controls
- Commissioning by a third party
Red Flags in HVAC Subcontractor Proposals
These patterns in a proposal or qualification call are worth paying attention to:
If the bid doesn't specify equipment or ductwork quantities, you can't compare it to other bids or hold the sub to a defined scope.
Permit and inspection management should be explicitly in scope. If it's not addressed, ask — and get the answer in writing.
Equipment pricing does fluctuate, but high-pressure tactics around bid expiration are a common inflation strategy.
Residential experience doesn't translate directly to commercial coordination. Ask for references from GCs on commercial projects of similar scope.
Working with a Local HVAC Sub in the St. Louis Market
Inspectors, permit offices, and supplier relationships in the St. Louis metro are relationship-driven. A local mechanical contractor who pulls permits regularly in your jurisdiction knows the inspectors, knows the typical turnaround times, and can navigate delays more effectively than an out-of-market sub.
That's not a reason to ignore price or scope quality — but it is a real operational advantage on commercial timelines where a one-week inspection delay can back up your entire close-out schedule.
Looking for a commercial HVAC sub in St. Louis?
Lolich Heating & Cooling works with general contractors on commercial build-outs, tenant improvements, and HVAC replacement projects across the greater St. Louis area. If you have a project coming up and want to talk scope or get a bid, reach out through the link below.