Start here: check that each bid is meant to deliver the same heating and cooling service. Then compare the load and sizing basis, exact equipment, work included, startup and verification, price terms, and warranty. A lower total is useful only after you know what it leaves out.
First decide which proposals can be compared
A heat-pump replacement is not automatically the same job as replacing a furnace. One proposal may include cooling while another prices heating only. A ducted system, a group of ductless indoor units, and a dual-fuel setup also distribute heat differently. Write down what the household expects the new system to do, including which rooms it serves and what equipment will remain.
If one contractor priced a heat pump and another priced a furnace plus air conditioner, ask each to state whether cooling, backup heat, electrical changes, and removal of the old equipment are included. Do not add a second cooling system to one total if the house will keep its current AC; do not treat a heat-only quote as equivalent to a heating-and-cooling package.
Check the design and equipment details
Ask what information was used to size the system and request the resulting load calculation or design summary. ENERGY STAR advises homeowners to have equipment sized for the home's actual characteristics rather than a rule of thumb. Its quality-installation guidance also recommends checking duct condition and airflow and confirming that the refrigerant charge is tested and adjusted.
Get the model numbers for the indoor and outdoor equipment, not just a brand name or a label such as “high efficiency.” For a heat pump, ask how the proposed system is expected to perform at the outdoor temperatures that matter at your home, whether backup heat is included, and what controls determine when it runs. If the project compares a heat pump with a furnace, ask for the furnace's AFUE and the heat pump's seasonal rating or a documented estimate suitable for the whole season. A rating at one temperature is not the same thing as a seasonal operating-cost estimate.
ENERGY STAR's homeowner guidance covers proper sizing and dual-fuel configurations. Its current product criteria can help interpret certification labels, but a product label does not confirm that a system is right-sized or correctly installed in a particular house.
Put installation scope beside the equipment
| Area | Ask each contractor to identify | How it affects comparison |
|---|---|---|
| Sizing and design | Load calculation or other documented sizing basis; areas served; design assumptions | Different designs may specify different system capacity or indoor-unit layouts. |
| Equipment | Indoor and outdoor model numbers; system type; rated performance; backup heat and controls | Brand names and nominal capacity alone do not describe the complete system. |
| Existing house | Duct inspection or changes; electrical circuit or panel work; refrigerant lines; condensate routing; equipment pad or mounting | These items can be included in one proposal and excluded or left unresolved in another. |
| Job completion | Permits, removal and disposal, startup, airflow and refrigerant checks, homeowner handoff | A quoted equipment price may not be the price of completed work. |
| Terms | Written total, allowances, exclusions, payment schedule, equipment warranty, labor coverage, and who handles registration | Unknown amounts and different warranty terms should remain visible instead of being guessed. |
The U.S. Environmental Protection Agency's ENERGY STAR quality-installation guidance recommends questions about home-specific sizing, duct evaluation, airflow, and refrigerant charge. Treat these as discussion points, not a substitute for the design, permits, code requirements, or professional assessment that apply to your project.
Separate “included,” “excluded,” and “not answered”
A blank line is not confirmation that the work is included. Mark each item as included, excluded, allowance, or unclear based on the proposal. If work is excluded, add a cost only after the contractor gives you a written amount. If an allowance may change with the product you select, ask how the final charge is calculated.
Request a revised written proposal when major scope differs. The Federal Trade Commission recommends getting multiple written estimates and checking the work description, materials, schedule, and price. Local licensing, permits, contract rules, and deposit limits vary, so check the requirements where the home is located.
Our contractor quote comparison tool can line up two or three estimates, add only documented costs for exclusions or allowance top-ups, and list open questions to take back to each contractor. It will not price missing work, rank contractors, or decide which design is suitable.
Compare the project price with future energy costs
When the decision is a heat pump versus a gas furnace, the installed quote is only one part of the comparison. Gather your electricity and gas prices, the annual heating demand or heating-only gas use, equipment ratings, maintenance estimates, and the written installed totals. Use the same heating demand and comparison period for both options.
The heat pump versus gas furnace calculator uses those figures to compare modeled fuel use, annual charges, installed amounts, and undiscounted totals over a period you choose. It does not look up prices, confirm incentives, size equipment, or model cooling, a dual-fuel changeover, financing, taxes, or future utility-rate changes. If you have two heat-pump bids for the same type of system, use the quote worksheet to compare scope; this calculator is for a heat pump against a gas furnace, not for ranking two heat pumps.
Only enter an incentive after checking that the program administrator confirms it applies to your location, household, equipment, and project. Keep the gross quote and the confirmed amount visible separately so a delayed or uncertain incentive does not make the upfront price look smaller than it is.
A short list to take to the next contractor visit
- What calculation or documented process did you use to size the system for this home?
- What are the model numbers and expected heating performance at the outdoor design temperature used for this proposal?
- Is this proposal for heating only, heating and cooling, or a dual-fuel system? What equipment stays?
- Which electrical, duct, line-set, condensate, permit, removal, and disposal tasks are included?
- What will you measure or test at startup, and what documentation will I receive?
- Which work is an allowance or exclusion, and how will a change in that amount be approved?
- What are the equipment and labor warranty terms, and who must register the equipment?
- Which incentive amount, if any, has been confirmed in writing, and who is responsible for filing?
Sources and limits
ENERGY STAR's HVAC quality-installation guidance covers sizing, airflow, refrigerant charge, and duct evaluation. ENERGY STAR's air-source heat-pump guidance discusses home-specific sizing and dual-fuel systems. The FTC's home-improvement guidance explains written estimates and consumer checks.
This guide helps organize questions; it does not assess a house, validate an equipment design, confirm an installer’s credentials, determine fair market pricing, or give tax or code advice. Requirements and utility conditions depend on location. Ask qualified local professionals and the relevant authorities for project-specific answers. Sources checked October 4, 2026.
For other replacement decisions, see the repair-or-replace calculator. For planned work beyond this installation, the maintenance reserve calculator helps organize savings around your own quotes and timing.