Building permits in Maui County, Hawaii
Find the right authority before you build. Maui County permitting follows Hawaii law — here is exactly who issues the permit and where to start.
County issues permits
County of Maui — Dept. of Public Works, Development Services Administration
Hawaii has no incorporated municipalities. The County of Maui Dept. of Public Works, Development Services Administration (Building Inspection / Plans Review & Permit sections) is the sole building-permit authority for Maui County, which includes Maui, Molokai, Lanai, and Kahoolawe.
Permit cheat-sheet (Hawaii rules)
| Project | Permit? | Authority | Typical fee | Timeline | Go / No-Go | Key notes |
|---|---|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | Permit required | county | Valuation-based; set by the county building department (R-3 / U occupancy schedule). | Plan review typically several weeks; varies by county workload. | Generally allowed | Hawaii’s statewide ADU law (Act 50, 2008) allows one accessory dwelling unit per single-family lot; the four counties administer permits and set local size/setback rules. Owner-occupancy and parking standards vary by county. Exempt: Statewide ADU law allows one ADU per single-family lot; counties set size limits (commonly 400–1,000 sq ft by county). |
| 🪵 Deck / Porch | Conditional | county | Valuation-based; set by the county building department. | Plan review for permitted decks; over-the-counter for simple low platforms where exempt. | Generally allowed | All structural lumber above ground must be preservative-treated for Formosan termite resistance per Hawaii’s amended code; wind-load design (105–170 mph gusts by location) applies. Verify with the county building department. Exempt: Platforms, walks, and driveways not more than 30 in above grade and not over a basement are exempt. |
| 🧱 Fence / Wall | Conditional | county | Permit fee set by county; many low fences are exempt from a building permit. | Exempt fences need no permit; over-height fences go through plan review. | Generally allowed | Vegetation-clearing, shoreline setback, and Special Management Area (SMA) review can add requirements even for exempt fences. Verify with the county. Exempt: Honolulu & Hawaii County: fences/walls over 6 ft require a permit; Maui allows up to 7 ft before a permit. Walls over 30 in (Honolulu) need a permit. |
| 🛖 Shed / Outbuilding | Conditional | county | Valuation-based; Hawaii County charges $10 per 100 sq ft for U-occupancy accessory structures. | Exempt sheds need no permit; permitted sheds go through plan review. | Generally allowed | Agricultural buildings may be exempt under HRS §46-88 (up to 1,000 sq ft nonresidential). Verify with the county building department. Exempt: One-story detached accessory buildings (storage sheds, tool sheds, playhouses) ≤120 sq ft are exempt in all four counties. |
| 🪜 Basement Finish | Permit required | county | Valuation-based; includes trade permits. | Standard plan review where basements are constructed. | Generally allowed | Basements are uncommon in Hawaii, but the same permitting logic applies when one is built or finished. Verify with the county building department. Exempt: Cosmetic finishing (paint, flooring) is exempt. |
| 🚗 Garage / Carport | Permit required | county | Valuation-based; includes trade permits. | New-structure plan review; varies by county. | Generally allowed | Attached and detached garages require a full building permit and plan review. Verify with the county building department. Exempt: New detached structures over 120 sq ft require a permit (smaller are still subject to zoning). |
| ☀️ Rooftop Solar PV | Permit required | county | Building + electrical permits; fee set by county. | Counties offer expedited/solar-specific review for standard rooftop PV. | Generally allowed | Provide racking structural design for tile or flat-roof installations; meet hurricane/wind uplift requirements. Verify with the county building department. Exempt: No size exemption; large/ground-mounted systems need structural review. |
| 🌡️ HVAC Replacement | Conditional | county | Mechanical permit; fee set by county (Maui lists Motors & HVAC trade permits). | Trade permits often issued same-day or over-the-counter. | Generally allowed | Equipment must meet current energy-efficiency and mechanical code requirements. Verify with the county building department. Exempt: In-kind replacement in the same location may be exempt; verify with the county. |
| 🍳 Kitchen Remodel | Conditional | county | Valuation-based when structural/plumbing/electrical work is included. | Standard review for permitted scopes. | Generally allowed | Hawaii’s energy code is reviewed on remodels (insulation, window U-factor, HVAC). Verify with the county building department. Exempt: Cabinet/countertop swap in the same layout is exempt. |
| 🛁 Bathroom Remodel | Conditional | county | Valuation-based when plumbing is relocated. | Standard review for permitted scopes. | Generally allowed | Ventilation to the exterior is required. Verify with the county building department. Exempt: Fixture-for-fixture swap in place is often exempt. |
| 🏗️ Room Addition | Permit required | county | Valuation-based; includes trade permits. | County plan review; multiple inspections. | Generally allowed | Lot-coverage, shoreline/SMA, and energy-code compliance are reviewed. Verify with the county building department. Exempt: No exemption — any new conditioned footprint requires a permit. |
| 🪟 Window / Door Replacement | Conditional | county | Usually no fee for in-kind swap; permit needed if opening is enlarged. | In-kind swaps typically need no review. | Generally allowed | Replacement products should meet energy-code U-factor when the code is triggered. Verify with the county building department. Exempt: Same-size, in-kind replacement is generally exempt. |
| 🏘️ Roof Replacement | Conditional | county | Often exempt/over-the-counter for same-footprint re-roof; fee set by county if required. | Same-material re-roof is typically exempt or over-the-counter. | Generally allowed | Counties list re-roofing with same/similar material for R-3/U occupancies as exempt. Verify with the county building department. Exempt: Same-material, same-slope re-roof often exempt. |
| 🅿️ Driveway / Parking Pad | Conditional | county | Building permit often not required; curb-cut/right-of-way work is separate. | Right-of-way permits reviewed by the county. | Generally allowed | A separate right-of-way permit is usually needed to cut the curb or connect to the street. Verify with the county. Exempt: Platforms, walks, and driveways not more than 30 in above grade are exempt. |
| 🏊 Swimming Pool / Spa | Permit required | county | Valuation-based; includes barrier/fencing and electrical bonding review. | Plan review; barrier inspection required before filling. | Generally allowed | Hawaii follows the IRC barrier requirements (4 ft minimum, no climbable openings). Verify with the county building department. Exempt: In-ground, >3 ft deep, or >5,000 gal pools always require a permit; above-ground prefab <24 in deep (or <5,000 gal, Maui) may be exempt. |
| 🧱 Retaining Wall | Conditional | county | Valuation-based when over the height threshold. | Over-threshold walls need plan review. | Generally allowed | Walls in hillside/SMA zones have stricter rules. Verify with the county building department. Exempt: Walls with ≤3 ft of retained earth and ≤6 ft total height (not supporting a surcharge or impounding liquids) are exempt. |
| 💥 Demolition / Teardown | Permit required | county | Demolition permit fee set by the issuing authority; verify locally. | — | Generally allowed | A full teardown or major strip-out requires a demolition (building) permit. Demolition permits commonly require proof of utility disconnects (water, gas, electric, sewer) and may require asbestos/lead-paint clearance for pre-1978 homes before work begins. Verify the issuing authority for your specific property. |
| 🚰 Septic System | Permit required | state | Septic permit fee set by the state environmental/health authority; engineered systems cost more. | — | Generally allowed | New or replacement onsite wastewater (septic) systems require a permit from the Hawaii Department of Health Wastewater Branch. A soil/perc evaluation and engineered design are typically required; licensed installers perform the work and the system is inspected before backfill. |
| 🔌 EV Charger | Conditional | county | Electrical permit; fee set by the issuing authority. | — | Generally allowed | A home EV charging station (240V branch circuit + wall-mounted EVSE) requires an electrical permit and must meet the NEC (Article 625). Many jurisdictions fast-track residential EVSE. A load calculation and possible service upgrade are reviewed. |
| ⚡ Standby Generator | Conditional | county | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
Frequently asked questions
Who issues building permits in Maui County, Hawaii?
County of Maui — Dept. of Public Works, Development Services Administration is the permitting authority for Maui County. The county issues permits for both unincorporated areas and incorporated cities. Start at the official portal linked above.
Do I go to the county or my city for a building permit in Maui County?
The county issues permits for both unincorporated areas and incorporated cities.
What home projects need a permit in Maui County?
The same project types shown in the cheat-sheet above (ADU, deck, fence, shed, solar, and more) — rules follow Hawaii state law. Whether the county or your city issues it depends on your property's incorporation status.
How do I apply for a permit in Maui County?
Use the official permit portal linked above. Most offices accept online submissions; have your plans, site information, and contractor details ready before applying.
Sources: County of Maui — Dept. of Public Works, Development Services Administration · City and County of Honolulu — Dept. of Planning & Permitting (Building Permits FAQ) · Hawaii County — Building Permits (Dept. of Public Works) · Maui County — Permits, Applications & Fee Schedule · Kauai County — Building Division Permitting