An HVAC estimate, line by line

A homeowner replacing a system has three estimates on the counter. Two say "3-ton AC and furnace, installed" with one number at the bottom. The third lists the condenser, the coil, the furnace, the permit and the haul-away, and says which warranty covers what. Be the third one. The other two leave the customer nothing to decide on but price.

Below are three HVAC estimates in the shape a customer receives them. Every dollar figure here is invented to show the structure. Build your own numbers from your loaded rate and margin target and see DoneQuote for HVAC contractors.

Scenario 1: 3-ton changeout, AC and gas furnace

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Estimate #2026-0412 Date: August 23, 2026 · Valid through: September 22, 2026

For: T. Reyes, 218 Winslow Ave, Columbus, OH 43201 From: Northline Heating & Air, 1400 Grandview Rd, Columbus, OH 43212 License #[your state or local mechanical license number] · (614) 555-0142 · [email protected]

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Replacing the 2007 split system in the basement. Cooling load calculated on site at 2.8 tons; equipment below is the nearest nominal size to that load, not a match to the old unit.

Subtotal: $9,330 Sales tax: per state rule — see the note below this estimate Total: $9,330 plus any applicable tax

Included: everything listed above, permit and inspection scheduling, disposal of the old equipment, refrigerant recovery by a Section 608 certified technician, startup readings documented and left with you, and manufacturer registration filed on your behalf.

Not included: electrical panel or circuit upgrades if the inspector requires one, gas line resizing, duct work beyond the transitions listed, drywall or paint, a condensate pump if the drain cannot run by gravity, venting work on the flue.

If we open a wall and find something unexpected, work stops and you get a written change order with a price before we go on.

Warranty: 10-year manufacturer parts warranty, subject to registration within the manufacturer's window. 2-year Northline labor warranty on our installation.

Schedule and payment: one day, two technicians. 40% at signing, balance on passed inspection. Net 15.

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Two lines you cannot copy from that page. Sales tax depends on your state. Some treat equipment installed into real property as a construction contract — you pay tax on materials and charge the customer none, which is Ohio's rule. Others tax the installed price or the labor, and many treat repair differently from new construction. Your state revenue department publishes contractor guidance; read it. The deposit: several states cap what a residential contractor may collect up front. California's limit is $1,000 or 10% of the contract price, whichever is less.

Scenario 2: no-cool service call

Repair estimates are short, and the diagnostic line is the one customers ask about. Say plainly whether you credit it.

Total: $400

Warranty: 1-year manufacturer parts warranty on both parts, 90-day labor warranty on the repair. Compressor and system faults found after this repair are separate work.

Scenario 3: thermostat and return-side duct repair

Total: $1,148

Name the equipment tightly enough to be compared

"New 3-ton system" is not a specification. Tonnage, efficiency rating and make and model let a customer set your page beside a competitor's and see that one of you quoted a single-stage builder unit and the other two-stage. Give the condenser model, the furnace model with its input BTU and AFUE, and the coil model. A mismatched coil changes the rated performance of the pair, which is why matched systems carry a combined AHRI reference number. Put that number on the estimate when you have it — it is the one line a customer can check without your help.

Rebates and credits move by utility, state and program year, and eligibility usually turns on the exact model. The federal 25C home improvement credit ended for property placed in service after December 31, 2025, so a 2026 install depends on whatever your state and utility still run. Name what you think the equipment qualifies for, say whether you file anything for them, and send them to their utility and a tax preparer rather than promising a dollar amount.

Sizing is a scope decision, not a footnote

Replacing like-for-like is fast and sometimes right. But the old unit may have been oversized, or the house may have had new windows and insulation since. A room-by-room load calculation is a different scope than reading the old data plate.

Whichever you did, put it on the estimate in one line — "sized from an on-site load calculation" or "matched to existing equipment capacity at your request". Skip the calculation and the new system short-cycles, and that sentence is the difference between a conversation and a callback you eat.

Permits, disposal and two different warranties

Permit and inspection rules for changeouts vary by city and county, not just by state, and so does who may pull the permit. Check your local building department and your state licensing board. Whatever it costs, show it as its own line. A $185 permit line reads as the cost of doing the job right; the same $185 inside a lump sum reads as padding when they find it later.

Haul-away and refrigerant recovery are the same story: real work with real disposal costs, invisible unless you write them down.

Warranty is where most estimates get vague. The manufacturer covers parts, often for years, usually conditional on registration inside a set window. You cover your labor, usually for far less. Write both, name the term for each, and state the registration condition. When a blower motor fails in year four, the customer will remember "ten-year warranty" and expect you to work for free.

Building these from a saved catalog

Three jobs, three ways of pricing: a changeout priced to a margin, a repair priced from a flat-rate book, a small job priced by the foot. In DoneQuote each of those is a saved priced item — equipment packages, flat-rate tasks, per-foot duct work — so you describe the job and the draft comes back with your own prices. Your review time goes to the scope notes instead of retyping model numbers.

An estimate that names the equipment, the permit, the disposal and both warranties takes longer to write than "3-ton system, installed." It also takes longer to argue with.