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HVAC / Mechanical: what bids leave out
HVAC bids can look comparable on tonnage and equipment brand and still cover very different work. One carries controls, test and balance, the crane pick, roof curbs and condensate piping. Another sets the units and runs the duct, and excludes everything that makes the system work as designed. Level on scope first.
Level your HVAC bids with this checklist →
Standard scope checklist
Send this to every bidder and ask them to mark each line Included, Excluded or give an Add $. Silence is not inclusion.
| # | Scope item |
|---|---|
| 1 | Equipment per schedule: make, model, tonnage, efficiency (or approved equal) |
| 2 | Equipment substitutions listed and called out |
| 3 | Crane / rigging for rooftop units |
| 4 | Roof curbs, curb adapters and structural support |
| 5 | Roof penetrations, flashing and coordination with the roofer |
| 6 | Ductwork: supply, return and exhaust per drawings |
| 7 | Duct insulation and lining |
| 8 | Grilles, registers and diffusers |
| 9 | Exhaust fans (restroom, kitchen, specialty) |
| 10 | Kitchen hood and grease duct (if any) |
| 11 | Gas piping to equipment |
| 12 | Condensate piping and drains |
| 13 | Refrigerant piping for split systems |
| 14 | Temperature controls: thermostats, BAS / DDC, programming |
| 15 | Control wiring (low-voltage) vs. line voltage power by electrician |
| 16 | Fire / smoke dampers and duct smoke detectors |
| 17 | Test, adjust and balance (TAB) by an independent firm |
| 18 | Startup, commissioning and owner training |
| 19 | Demolition and disposal of existing equipment and duct |
| 20 | Refrigerant recovery from existing equipment |
| 21 | Temporary heating or cooling during construction |
| 22 | Filters during construction and final filter change |
| 23 | Coring, sleeves and firestopping |
| 24 | Permits, mechanical inspections and fees |
| 25 | Warranty term (parts vs. labor, compressor) |
| 26 | Sales tax, bond and prevailing wage |
Common exclusions and how they are worded
| Exclusion | Typical wording | Why it matters | Typical cost to cover |
|---|---|---|---|
| Controls |
| A bid with basic thermostats isn't comparable to one carrying the specified building automation and programming. Controls are one of the biggest hidden scope differences. | TBD |
| Test & balance |
| Without balancing, rooms run hot or cold and you can't prove the system meets design. It's often spec'd as owner-hired, so budget it either way. | TBD |
| Crane & rigging |
| Rooftop units have to be lifted. Crane cost depends on unit weight and site access, and it's often excluded. | TBD |
| Roof curbs & roofing work |
| New units need curbs, framed openings and flashing. These sit between the mechanical, roofing and structural trades, and gaps here cause leaks. | TBD |
| Line-voltage electrical |
| The HVAC contractor typically wires controls and the electrician brings power and disconnects. Check that the two bids meet without a gap. | TBD |
| Condensate & gas piping |
| Condensate drains and gas lines to equipment can be carried by HVAC or plumbing. Make sure one of them prices it. | TBD |
| Fire / smoke dampers & duct detectors |
| Dampers and duct detectors are life-safety items that cross HVAC, fire alarm and electrical scopes. Spell out who furnishes, installs, wires and tests them. | TBD |
| Equipment substitutions |
| A lower bid may be based on different equipment than specified. Check model numbers, efficiency and warranty before you treat it as equal. | TBD |
| Demolition & refrigerant recovery |
| Old units and duct have to come out, and refrigerant has to be recovered by a certified tech before disposal. | TBD |
| Temporary conditioning |
| Drywall, paint and flooring need climate control. If the permanent system can't be used, temporary units are a real cost. | TBD |
“Typical cost to cover” is TBD. We will publish ranges only once we have real, sourced data. Until then, use your own estimate or a confirmed add price from a bidder.
Questions to ask bidders
- What equipment did you price (make, model, efficiency)? Any substitutions from the schedule?
- Are controls included to the level in the spec, including programming and integration?
- Is test and balance included? By an independent firm?
- Are crane, rigging, curbs and curb adapters included?
- Who handles roof openings, framing and flashing at new units?
- Where does your wiring stop and the electrician's start? Who provides disconnects?
- Are condensate and gas piping included to every unit?
- Who furnishes, installs and wires fire/smoke dampers and duct detectors?
- What warranty is included, and does it cover labor?
Bid-ready HVAC contractors
Contractors who agree to price against the standard checklist above, with exclusions spelled out line by line. Listings are not live yet.
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Bids on the BidGaps checklist
Featured listing
Your company · City, ST
Bids on the BidGaps checklist