Research by DoINeedAPermit Research Team · Updated May 2026
The Short Answer
Heat pump installations in Auburn require a mechanical permit in almost all cases. The exception is a like-for-like replacement of an existing heat pump by a licensed contractor — even then, many contractors pull a permit anyway for rebate eligibility. New installs, conversions from gas furnaces, and supplemental heat-pump additions are all permittable work.
Auburn's Building Department enforces Washington State mechanical code (currently the 2021 IECC and IBC) and requires a permit for any heat-pump work that changes system type, capacity, location, or electrical load. Unlike some Puget Sound neighbors (e.g., Renton, which has streamlined OTC mechanical permits for ENERGY STAR heat pumps under 60K BTU), Auburn does not yet offer an expedited category — all heat pump permits route through standard plan review, typically 1–2 weeks. Auburn is also in King County Climate Commitment Act territory, which means certain rebate programs (Puget Sound Energy's heat pump incentives, up to $5,000) apply only to permitted installations. Electrically, your install must comply with NEC Article 440 (air-conditioning/refrigeration equipment) and pass both mechanical and electrical inspection. The city's frost depth (12 inches in the Puget Sound basin, where most of Auburn sits) affects outdoor-unit placement and condensate-line routing. Federal IRA credits (up to $2,000 for heat pumps, 30% of cost) do not require a permit, but state and utility rebates almost always do — so skipping the permit costs you $1,000–$5,000 in incentive money.

What happens if you skip the permit (and you needed one)

Auburn heat pump permits — the key details

Auburn follows Washington State's 2021 International Building Code and International Energy Conservation Code. The Building Department's mechanical section requires a permit for any heat-pump installation (new, replacement with different tonnage, conversion from gas/oil, or supplemental cooling/heating). The rule is straightforward: if the work involves a compressor, condenser, or air handler that is new to the home or changes the system's capacity or type, it is permittable. A true like-for-like replacement — identical tonnage, same outdoor location, same indoor air-handler location, no electrical upgrades — may qualify for an exemption if executed by a licensed mechanical contractor and documented on the permit application as 'existing system replacement, no capacity change.' However, most Auburn contractors pull a permit anyway (cost is $200–$400) because the rebate programs (Puget Sound Energy's residential heat pump rebate, up to $5,000; King County's electrification incentive, up to $2,500) explicitly require a permitted permit card issued by the city. Skipping the permit to save $300 in permit fees costs you $3,000–$7,500 in incentives.

Washington State enforces the NEC (National Electrical Code) and requires heat-pump electrical work to comply with NEC Article 440 (room air conditioners and heat pumps), NEC Article 690 (solar photovoltaic systems, if applicable), and NEC Article 210 (branch circuits and outlets). Your electrician must size the breaker and wire gauge for the compressor's running load plus the air handler's blower motor. Heat pumps rated 240V at 20A require a dedicated 20A or 25A breaker; larger units (30A–60A) need oversized service panels. Auburn's permit will flag undersized service (e.g., 100A panel with no spare breaker slots) and require an upgrade. The mechanical permit plan must show refrigerant-line routing, clearance from property lines (IRC M1305 requires 3 feet minimum for outdoor condensing units in most jurisdictions; Auburn typically enforces this), condensate-drain routing (must be pitched to daylight or sump, not into crawlspace), and backup heat specification (heat pumps in Auburn's zone 4C Puget Sound have moderate winter performance, but zone 5B east-side areas — Auburn extends to the foothills — have harsh winters requiring electric resistance or gas backup). Your contractor must submit a load calculation (Manual J per ASHRAE 183) showing the building's heating and cooling demand and confirming the heat pump tonnage is adequate. Undersized equipment is a common permit rejection.

The electrical inspection is critical. Auburn's inspection team will verify that the heat pump's disconnect switch is rated for the equipment (240V, 60 Hz, correct amperage), that it is located within 10 feet of the outdoor unit (per NEC 440.14), that wiring is correctly sized and routed (in conduit where exposed), and that the panel has a two-pole breaker matching the compressor nameplate rating plus 125% of full-load current (per NEC 440.52). If your home's electrical panel is under 200 amps or has no spare breaker slots, a service upgrade may be required, adding $1,500–$3,000 and 2–3 weeks to the timeline. The building department issues a permit card (currently via Auburn's online portal or in-person at City Hall); once the permit is issued, the contractor or owner schedules inspections: typically a rough mechanical inspection (before refrigerant charge and final connections), electrical rough (before panel cover), and final (after startup and performance testing). Most contractors complete this in one or two visits.

Auburn's permit fees for heat-pump installation are based on valuation (estimated cost of the work). The city calculates mechanical permit cost as a percentage of project value: typically $1.5–2.0 per $100 of work value. A $6,000 heat-pump install (equipment + labor) costs $90–$120 in permit fees. A $10,000 conversion (furnace-to-heat-pump, including service-panel upgrade and ductwork) costs $150–$200. Additional inspections (electrical, if required) are bundled. The permit is valid for 180 days; if work is not started within that window, it expires and must be re-pulled. Timeline from submission to final inspection is typically 2–4 weeks for Auburn's standard plan review, though expedited review (same-day OTC for simple replacements) is not officially available — so plan ahead. Federal IRA credits (30% of equipment cost, up to $2,000 per household) are automatic if you file Form 5695 with your tax return; no state or local approval needed. But Washington State's Clean Energy Fund rebates (up to $2,000 for income-qualified homes) and Puget Sound Energy's heat pump rebate (up to $5,000 depending on ENERGY STAR tier) require a copy of the city's permit card and proof of installation. These rebates often reduce your net cost to $1,000–$4,000 after incentives.

Condensate and drainage are overlooked but critical in Auburn's climate. Heat pumps in cooling mode produce 30–50 gallons of condensate per day on hot, humid days (rare in Auburn, but July–August can trigger it). The indoor coil drains via a copper or PVC line pitched to daylight (crawlspace, exterior wall) or to a condensate pump (for basements). Many older Auburn homes have cramped crawlspaces or uninsulated foundation areas; your contractor must plan the drain routing during the permit phase. The outdoor unit also requires clearance: 3 feet minimum from property lines, 2 feet from walls (for airflow), and 12 inches of space above for air intake. In Auburn's rainy climate, the unit must be on a sloped pad or elevated plinth to avoid standing water (which corrodes the aluminum fins). If your lot is on a slope or near a wetland (common in South King County), the building department may require a grading or stormwater review in addition to the mechanical permit. This adds 1–2 weeks but is rare for single-family installations. Lastly, Auburn is served by Puget Sound Energy (PSE) and some smaller co-ops; PSE's rebate requires ENERGY STAR Most Efficient certification (typically Tier 2 or higher on the AHRI directory). Your contractor should confirm the heat pump model is on the qualifying list before purchase — this is often a condition of the rebate approval.

Three Auburn heat pump installation scenarios

Scenario A
Like-for-like heat pump replacement, 3-ton Fujitsu, same location (Auburn residential, Puget Sound zone)
You have a 10-year-old 3-ton Fujitsu mini-split (outdoor condenser on west wall, two indoor wall units in living room and master bedroom). You want to replace it with a new 3-ton Fujitsu AOU36RLXFZ (same capacity, same location). Your licensed HVAC contractor says 'this is a like-for-like replacement, we might not need a permit.' Here is the reality: Washington State and Auburn technically allow exemption for replacements of equal tonnage and location, but the exemption applies only if the old unit and new unit are identical in electrical characteristics (same breaker size, same wiring requirements). Most contractors pull a permit anyway because: (1) the Puget Sound Energy rebate ($2,000–$3,000 for a like-for-like replacement of an ENERGY STAR unit) requires a permitted permit card, and (2) if the old unit's breaker is undersized (20A for a 3-ton unit is marginal), the new unit may require a 25A or 30A breaker, triggering electrical work that requires a permit. If you do not pull a permit and later want to claim the PSE rebate, you will be denied. Cost to pull the permit: $200–$250. Cost to lose the rebate: $2,500. Recommendation: pull the permit. Timeline: 1–2 weeks plan review, 1–2 inspection visits (mechanical and electrical). Inspection will verify the new outdoor unit's clearance (3 feet from property line, you are on a corner lot so the west wall must be 3 feet from the neighbor's property or have written easement), condensate drain routing (the old line went to ground; new unit must do the same), and electrical disconnect is properly rated. If the property-line setback fails, you may need to relocate the outdoor unit to the east wall (shadier, less efficient, but compliant) or request a variance from the city. Most north Auburn lots are deep enough that this is not an issue.
Permit required ($200–$250) | Electrical inspection (bundled) | 2 inspection visits | PSE rebate $2,500–$3,000 (requires permit) | Federal IRA 30% ($2,000 max) | Total cost after rebates $2,000–$4,000
Scenario B
Furnace-to-heat-pump conversion, new 4-ton unit, full ductwork retrofit, 200A panel with spare breaker (Auburn residential, foothills zone 5B)
You live in the Auburn foothills (east of I-5, closer to Enumclaw), in climate zone 5B with winter temperatures dropping to 0–5°F. You have a 30-year-old natural gas furnace (80 AFUE) and want to replace it with a 4-ton cold-climate heat pump (e.g., Carrier 25HNH/25HCC or equivalent, SEER2 16+, rated to -13°F) plus backup electric resistance (15 kW). This is a conversion project, not a like-for-like replacement — it requires a full mechanical permit plus electrical. The load calculation (Manual J) will show that your 2,500 sq-ft home needs 60,000 BTU heating (100% from heat pump down to -13°F, with resistive backup for extreme cold). The heat pump condenser goes on the north side of the house (prevailing westerlies, some shade in winter to reduce noise). New supply and return ductwork must be insulated (R-8 minimum per IECC) because heat-pump supply air is cooler than furnace supply (typically 95–105°F vs 130°F). Your electrician will run a 40A, 240V dedicated circuit from the panel to the outdoor condenser (on a 60A breaker to handle 125% of the 40A nameplate current per NEC 440.52), and a separate 30A circuit to the air handler (with 15 kW electric resistance). Your panel is 200A with a spare 60A slot (two 30A breakers), so an upgrade is not needed. Permit process: mechanical plan (load calc, unit specs, ductwork route, condensate plan, backup heat details), electrical plan (breaker sizing, wire gauge, disconnect location, panel diagram). Both plans are reviewed simultaneously; rejections are typically: insufficient backup heat detail (how many kW of resistance?), ductwork insulation not specified, or condensate drain routing unclear. Plan review: 1–2 weeks. Inspections: rough mechanical (before refrigerant charge), electrical rough (before panel cover), final (after startup and performance test, including heat-pump thermostat commissioning to confirm backup-heat setpoint). Total timeline: 3–4 weeks. Permit cost: $250–$400 (based on project valuation ~$12,000–$15,000). Federal IRA credit: 30% of equipment (not labor) up to $2,000, so $4,500 heat pump becomes $3,150 after 30% credit = $1,350 IRA benefit (capped at $2,000 per household). Washington State's Clean Energy Fund (if income-qualified, <80% AMI): up to $2,000 rebate (state funded). Puget Sound Energy: cold-climate heat-pump rebate up to $2,500 (for ENERGY STAR Most Efficient units in zone 5B). Total incentives: $4,000–$6,500. Net cost after rebates and federal credit: $6,000–$9,000 for a $12,000–$15,000 system.
Permit required ($250–$400) | Mechanical + electrical inspection | Load calculation (included in bid or $300–$500 separate) | Ductwork insulation mandatory | Backup electric heat 15 kW | 3–4 week timeline | Federal IRA 30% + state/utility rebates $4,000–$6,500 | Net cost $6,000–$9,000
Scenario C
Supplemental heat-pump mini-split (cooling only, 2-ton), existing furnace remains, no electrical service upgrade (Auburn residential, Puget Sound zone, 100A panel)
You have a 1970s home with a gas furnace (heating) but no air conditioning. You want to add a 2-ton mini-split (outdoor unit in back yard, two 12K BTU indoor units on living-room and bedroom walls) for summer cooling and part-time shoulder-season heating. This is a supplemental add-on: the furnace stays for winter, the heat pump provides cooling and April/May heating when it is more efficient than the furnace. This requires a mechanical permit (new refrigeration equipment) and electrical permit (new 240V circuit). The load calculation (Manual J cooling) will show you need 24,000 BTU cooling capacity for the whole house; a 2-ton (24K BTU) unit is appropriate. However, your panel is 100A with only one spare breaker slot (the furnace is on a 20A 120V circuit for the control transformer). A 2-ton heat pump requires a 20A, 240V dedicated breaker minimum (per NEC 440). The electrician can fit a 20A breaker in the spare slot (upgrade not required). But the building department's plan reviewer will ask: do you have 100A service sufficient for simultaneous heat-pump operation (20A) + other loads (kitchen, laundry, lights)? Typically 100A is minimum for a modern home, and if you add the heat pump, the total load is tight. The plan review may require a load analysis (simple, 30 minutes of calculation). If the analysis shows the service is inadequate, a 150A or 200A upgrade is required ($1,200–$1,800). Assuming no upgrade: permit cost $180–$250 (lower valuation, ~$5,000–$6,000 equipment cost). Inspections: mechanical (outdoor unit clearance, condensate drain), electrical (disconnect, breaker size, wire gauge). Rejection risk: if condensate drain is routed into crawlspace or if outdoor unit is too close to property line (less than 3 feet) or to a bedroom window (typically 5 feet minimum for noise). Plan ahead. Timeline: 2–3 weeks. Federal IRA credit: none (supplemental cooling-only not qualified; if you enable heating, you may qualify for $2,000). Puget Sound Energy cooling rebate: up to $1,000 for ENERGY STAR mini-split. Net cost after rebate: $4,000–$5,000.
Permit required ($180–$250) | Electrical inspection (20A, 240V circuit) | No service upgrade if 100A is adequate (verify) | Outdoor unit 3+ feet from property line | Condensate to daylight (not crawlspace) | Puget Sound Energy cooling rebate $1,000 | Federal IRA not available for cooling-only | Net cost $4,000–$5,500

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Manual J load calculation: why Auburn requires it and what it costs

Auburn's Building Department (via Washington State mechanical code adoption) requires a Manual J load calculation for any new heat-pump installation or conversion. Manual J is a standardized method (ASHRAE 183) that calculates a home's peak heating and cooling demand based on climate zone, square footage, insulation R-value, window U-factor, occupancy, and internal gains. The result is expressed in BTU per hour (e.g., 48,000 BTU heating, 36,000 BTU cooling). Your heat pump must be sized to meet or exceed this demand. Undersized equipment is the #1 reason for heat-pump dissatisfaction and is also a permit rejection — the city's plan reviewer will compare the Manual J demand to the equipment BTU nameplate and flag undersized units.

Auburn's climate zone complicates the calculation. The Puget Sound lowlands (west Auburn, where most of the city sits) are zone 4C: mild winters (design temp 0–5°F), cool summers (85°F), high humidity (80–90% in summer). A 2,000 sq-ft home in zone 4C might need 36,000 BTU heating and 24,000 BTU cooling. But east Auburn (foothills, higher elevation, closer to the Cascade passes) is zone 5B: harsh winters (design -10 to -15°F), cool summers (same), lower humidity. The same 2,000 sq-ft home in zone 5B needs 60,000 BTU heating and 18,000 BTU cooling. This matters: a contractor who pulls a zone 4C unit to an east Auburn home will undersize heating, and the system will struggle or require excessive backup heat in January. Your load calc must account for your exact location (zip code, elevation, shade from trees/buildings).

Cost: if your contractor includes a Manual J in the bid, it is usually free or bundled into the equipment cost ($0–$200). If you hire a third-party energy auditor or engineer, expect $300–$600. Many Auburn contractors (especially larger HVAC firms like All Star or Reliable) have software and will pull a load calc in-house. Small contractors sometimes skip it and rely on rule-of-thumb (500 sq-ft per ton), which is risky — insist on a formal load calc and ask to see the document before the permit is submitted. The building department's plan reviewer will include the Manual J document with the permit; if it is missing or shows undersized equipment, the permit will be returned for revision (adds 1–2 weeks).

The load calc also determines backup-heat strategy. In zone 5B, a heat pump alone cannot heat below -13°F (the balance point); below that, electric resistance or gas must supplement. The Manual J output drives the backup-heat sizing: if the load calc shows 60,000 BTU heating demand and the heat pump is rated for 40,000 BTU at -13°F, you need 20,000 BTU (27 amps at 240V, roughly 10 kW) of electric resistance backup. This is specified on the permit plan, inspected, and tested before final sign-off.

Why Auburn heat-pump permits take 2–4 weeks (and how to speed it up)

Auburn's Building Department does not currently offer same-day or over-the-counter (OTC) approval for heat-pump permits, unlike some nearby cities (Renton offers OTC for certain ENERGY STAR units under 60K BTU). All Auburn permits route through the standard plan-review queue, which is currently averaging 1–2 weeks turnaround for mechanical and electrical combined. The process: (1) contractor submits online via Auburn's permit portal with mechanical plan (load calc, unit specs, ductwork, condensate, backup heat) and electrical plan (breaker, wire, disconnect); (2) plan reviewer (typically a state-licensed mechanical inspector) checks for code compliance (NEC 440, IRC M1305, IECC ductwork insulation); (3) if compliant, permit is issued and contractor can schedule inspections; (4) if non-compliant, plan is returned with marked-up comments and resubmission is required (adds 1–2 weeks). Common rejections for Auburn heat pumps: Manual J missing or equipment undersized, backup heat not detailed (east-side foothills), condensate routing unclear, outdoor unit within 3 feet of property line, ductwork R-value not specified, electrical panel load analysis missing (for 100A services).

Speed-up strategies: (1) use a contractor with Auburn experience — they know the plan reviewer's preferences and submit compliant plans on the first try; (2) pre-coordinate with PSE if claiming rebates — get the rebate pre-approval (confirms ENERGY STAR and climate zone) before permit submission, reducing the building department's energy-code review time; (3) hire a third-party Manual J engineer if your contractor resists doing a formal load calc — having a stamped load calc saves back-and-forth; (4) if your home is in a historic district (Auburn has several, e.g., downtown Auburn, Brackett Hills) or flood zone, notify the contractor early — these overlays may require additional city staff review, adding 1–2 weeks. Most contractors will submit a permit on Monday and have it approved by Friday of the next week if everything is clean. Plan 3 weeks to be safe.

Inspection scheduling also affects timeline. Once the permit is issued, you must coordinate with the city's inspection team. Most Auburn inspectors work Monday–Friday, 8 AM–4 PM, and book 1–2 weeks out. A rough mechanical inspection takes 30 minutes (outdoor unit placement, disconnect location, ductwork insulation); electrical rough takes 15 minutes (breaker, wire, panel); final inspection takes 45 minutes (startup, performance test, thermostat commissioning, indoor/outdoor temp differential check). Many contractors can complete all three in two visits (rough mechanical + electrical, then final) over 1–2 weeks. If you fail an inspection (e.g., outdoor unit too close to property line), you have to correct it and reschedule, adding another week. Build in a buffer: assume 3–4 weeks total from permit submission to final approval and incentive claim.

Auburn's permit portal (https://auburn.municipal.codes or the city's e-permitting system) allows tracking. Contractors and homeowners can log in to see the permit status, plan-review comments, and inspection scheduling. Make sure your email is on the permit so you receive notifications. Some contractors do not use the online portal and still file in person at City Hall (425 Oak St S, Auburn, 98001); this is slower and not recommended. Insist on online filing.

City of Auburn Building Department (Division of Building Services)
425 Oak Street South, Auburn, Washington 98001
Phone: (253) 931-3011 (main city line; ask for Building Services) | https://auburn.municipal.codes (online permit portal and code lookup)
Monday–Friday, 8:00 AM–5:00 PM (confirm holiday closures)

Common questions

Can I install a heat pump myself in Auburn, or do I need a licensed contractor?

Electrically, no — the NEC requires a licensed electrician for all 240V circuits and panel work. Mechanically, Washington State allows owner-builders (owner-occupied single-family homes) to perform some mechanical work, but Auburn's Building Department requires that the mechanical permit applicant be the homeowner, and the city typically inspects more closely for owner-performed work. Refrigerant handling requires EPA Section 608 certification (even for evacuating old refrigerant), which is restricted to licensed technicians. Recommend hiring a licensed HVAC contractor for the whole job — the cost savings of DIY are offset by liability, warranty loss, and inspection risk.

Do I lose my PSE rebate if I pull a permit late (after installation)?

Yes. Puget Sound Energy's heat pump rebate ($2,000–$5,000 depending on tier) requires a copy of the Auburn permit card and a final inspection report issued before you claim the rebate. If you install the heat pump without a permit and then apply for the rebate, PSE will deny it. Retrofitting a permit after the fact (after work is complete) is possible but expensive — the city may require a full re-inspection and will likely charge a late-permit penalty (50–100% surcharge, adds $200–$500). Do not skip the permit to save money; the rebate loss is 10x larger.

What is the difference between a like-for-like heat pump replacement and a new installation in Auburn's eyes?

Like-for-like: same tonnage (3-ton for 3-ton), same location (outdoor condenser on west wall), same electrical requirements (20A breaker for 20A nameplate). Washington State technically exempts like-for-like replacements by licensed contractors. However, Auburn's Building Department and Puget Sound Energy both require a permitted permit card to claim rebates, and most contractors pull a permit anyway. If the new unit requires a larger breaker or wiring upgrade (e.g., old 20A unit, new 30A unit), it is no longer like-for-like and definitely requires a permit. New installation: any addition of heat-pump capacity or a conversion from gas/oil furnace to heat pump is a new installation and requires a full permit.

My home is in a historic district (e.g., downtown Auburn). Does this affect the heat pump permit?

Possibly. Auburn's historic districts have design-review guidelines that may restrict outdoor-unit placement (color, visibility from street, setback). Your contractor must coordinate with the Historic Preservation Commission before submitting the permit. Outdoor units are often routed to rear yards or side yards out of public view. This can add 1–2 weeks to the permitting timeline if a design-review meeting is required. Confirm your historic-district status on Auburn's GIS mapping or call the Building Department.

Does my 100A electrical service need to be upgraded for a heat pump?

Not always. A 2-ton heat pump on a 20A, 240V circuit can fit into a 100A panel if there is a spare breaker slot and the total load (heat pump + other circuits) does not exceed 100A simultaneous demand. Most homes are fine. However, if you have a large 3.5–5 ton heat pump, a large electric resistance backup (15+ kW), or an electric vehicle charger, you may need a 150A or 200A upgrade ($1,200–$1,800). The electrical plan review will flag this; do not assume you are safe. Ask your electrician to run a load calculation (30 minutes, included in estimate or free from PSE) before bidding.

What if my outdoor unit is within 3 feet of my neighbor's property line?

It will fail inspection. IRC M1305 (Washington State adopts this) requires 3 feet minimum clearance for condensing units. If your lot is narrow or the desired location is less than 3 feet from the property line, you have two options: (1) relocate the unit to a compliant spot (often the side or rear yard, even if less ideal for noise), or (2) request a variance from the City of Auburn. Variances are rare and require showing hardship; they typically are not granted for HVAC equipment. Plan ahead: have your contractor survey the property line before the permit is submitted.

Can I claim the federal IRA tax credit and the PSE rebate at the same time?

Yes, they are separate programs. The federal IRA credit (30% of equipment, up to $2,000 per household per year) is claimed on your tax return (Form 5695) with the IRS. Puget Sound Energy's rebate (up to $5,000, varies by climate zone and ENERGY STAR tier) is a separate incentive paid by PSE. You can stack them: e.g., a $6,000 heat pump system costs $6,000, you get $2,000 federal IRA credit, $2,500 PSE rebate, and your net cost is $1,500. However, if you are also eligible for a state rebate (Washington's Clean Energy Fund, income-qualified) or a local incentive (King County electrification rebate), verify the stacking rules — some programs have caps or exclusions if combined with other incentives. PSE's website has a full stacking guide.

How do I know if my heat pump model qualifies for the Puget Sound Energy rebate?

PSE maintains a list of ENERGY STAR Most Efficient heat pumps on their website (puget-sound-energy.com or search 'PSE heat pump rebate'). The list is updated monthly. Your contractor should confirm the specific model (e.g., Carrier 25HNH048A00) is on the list before purchase. Models must meet SEER2 16+, HSPF2 10+, or higher depending on climate zone (zone 4C has slightly lower thresholds than zone 5B). If you buy a unit not on the list, you forfeit the rebate. Ask your contractor for a rebate pre-approval letter from PSE before purchase — this confirms eligibility and can be submitted with the permit to speed up plan review.

What happens to my natural gas furnace when I convert to heat pump — do I have to remove it?

Not necessarily. If you are installing a heat pump as a backup system (backup electric resistance or gas furnace remains for extreme cold), the old furnace can stay, provided it is properly isolated (gas line capped or removed, electrical control power supplied only when heat pump cannot meet demand). However, Auburn's Building Department and Puget Sound Energy both encourage full conversion (removing the furnace entirely) for simplicity and emissions reduction. If you keep the furnace as backup, the system must have an automatic changeover control (thermostat detects when heat pump is insufficient and switches to furnace). Many contractors recommend removing the old furnace entirely and using electric resistance for backup — simpler, fewer moving parts, and qualifies for maximum rebate. Confirm your contractor's approach in the permit plan.

Can I have the heat pump permit pulled while I wait for rebate pre-approval from PSE?

Yes. The permit process and rebate process are independent. However, submitting rebate pre-approval (a 1-page letter from PSE confirming the model is ENERGY STAR qualified and the incentive amount) with the permit helps the plan reviewer verify the unit is appropriate and speeds approval. Many contractors bundle this: they request rebate pre-approval from PSE (2–3 days) while preparing the permit plans, then submit both together. PSE's pre-approval does not guarantee payment — you must complete the installation, pass final inspection, and submit proof of purchase/installation to claim the rebate.

Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current heat pump installation permit requirements with the City of Auburn Building Department before starting your project.