Seattle Heat Pump Cost Estimator

How the estimator works

The estimator matches your answers to published Seattle-area price ranges and to the incentive programs that apply to your utility and heating system. It does not invent a number for your house. The Seattle Heat Pump Company built it so you can see what a ducted heat pump project usually costs before anyone visits, and which parts of a future quote are likely to carry the weight.

Your ZIP code sets the utility, which matters more than most people expect. Seattle City Light and Puget Sound Energy (PSE) run different rebate programs, charge different electric rates, and so change both the net price and the running cost. Some ZIPs straddle a city line, and Renton is split between City Light and PSE by address, so for those the estimator asks you to choose.

Your current system decides the base range. Replacing an existing ducted heat pump uses the like-for-like range of $6,700–$15,000. Everything else, from an oil furnace to a gas furnace with or without AC, uses the installation range of $6,700–$20,000. Add-ons such as a panel upgrade, oil tank decommissioning or duct work appear on separate lines, each with its own published range, and they are never folded into one total.

What the numbers are based on

Every figure in the tool comes from a named, published source. Ranges are typical budgeting figures for Seattle-area projects, not quotes, and incentives change, so confirm current terms before you sign.

• Installation range. National cost guides put a central ducted heat pump at about $5,000 to $15,000 (Fixr) or $4,000 to $12,000 on existing ducts (HomeGuide). The Bonneville Power Administration's regional figure for high-performance ducted retrofits averages about $17,000. Seattle-area survey data starts around $6,700. The range spans that evidence rather than averaging it.
• Panel upgrade. About $1,333–$4,500 for a 100 to 200 amp upgrade in the Seattle area. City Light's own service-side charges are not published.
• Oil tank fill in place. About $700–$3,000 on a clean site, plus the $184 Seattle Fire Department permit per tank. Removal, soil sampling and leak cleanup have no fixed range.
• Permits. About $192–$556 for a typical Seattle job under the current SDCI fee schedule, which includes the 5% technology fee.
• Incentives and rates. City Light's contractor discount tiers, the Seattle Clean Heat program, PSE's published rebates, and each utility's current residential rates.

Why there is no single number

A heat pump is sized from a Manual J load calculation, which Seattle's energy code requires, and the equipment may not be larger than the smallest size that meets the load. Two houses of the same floor area can need very different capacity because of insulation, windows, air leakage and ceiling height. A formula that multiplies square footage by a dollar figure looks precise and is not, so the estimator does not use one.

Instead, it tells you which way your answers lean. A coil sitting on a sound gas furnace usually keeps the indoor side cheaper. An oil conversion, where an electric air handler replaces the furnace, pushes toward the high end, as do higher-efficiency equipment, cold rooms that point to duct problems, and a small panel that may need an upgrade. Those notes are qualitative on purpose.

Running costs and the break-even point

The running-cost note compares a heat pump with a 95% efficient gas furnace using each utility's current rate and PSE gas at about $1.67 per therm. The comparison comes down to the coefficient of performance (COP), the units of heat delivered per unit of electricity. On City Light's Seattle rate the heat pump wins above a COP of about 2.2; on its suburban rate, about 2.4; on PSE electricity, about 3.4. That last number is why dual fuel often makes sense on the Eastside. There is no official heating oil price series for Washington, so the tool does not pretend to compare oil running costs. The operating cost guide works through the math.

What the estimator cannot tell you

It cannot see your ducts, your panel or your yard. Duct work is shown as "priced after a static pressure test" because nobody can price it honestly before measuring airflow; the national range for whole-house duct replacement, $1,400–$5,600 (HomeGuide), is there only for context. It does not know whether an oil tank has leaked, whether a side-yard location will pass Seattle's noise review, or whether City Light needs to change your service connection. It also cannot confirm rebate eligibility; programs set their own rules, and some require a participating contractor or approval before work starts.

If your house has no ducts at all, this tool is the wrong starting point. The heat pump readiness assessment explains the options honestly, and the ducted vs ductless guide compares the two approaches.

Using the range when quotes arrive

Hold every quote against the range and the add-on lines. A quote well below the range often leaves out ducts, electrical work or permits. One well above it may include work you need, or an efficiency tier you did not ask for. The quote comparison checklist lists the line items to ask for, the Seattle cost guide explains each driver in depth, and the Seattle rebate guide keeps the incentive details current. The copy-link button saves your answers in the page address, so you can send them to someone else or come back later.