CHECKLIST_01 / 46 items
ADU pre-construction checklist
46 items · 7 stages · Before you break ground
The internal pre-construction walkthrough Golden State runs before every ADU and major remodel in the Puget Sound. Miss any of these and you risk a stop-work order, a permit revision, or a $40k surprise. Use it as your own kickoff agenda.
1 · Lot & site
- Confirm parcel zoning and overlay districts in your city's GIS.
- Pull a current Assessor record — confirm legal lot of record, not a tax-only parcel.
- Order a boundary survey if existing record drawings are >10 years old.
- Check critical areas: steep slope, wetland, stream buffer, liquefaction.
- Locate every easement on title — utility, access, drainage.
- Identify tree retention requirements; tag protected trees before design.
- Verify setbacks against ADU code (front, side, rear, eave projection).
- Confirm max lot coverage and FAR with the new ADU added.
2 · Code & zoning
- Read your city's current ADU ordinance end-to-end — not a third-party summary.
- Confirm owner-occupancy rule (most WA cities no longer require it post-HB 1337).
- Verify allowed height (typically 18–24 ft for DADU in Puget Sound).
- Confirm parking requirement — most cities now waive within transit overlays.
- Check entry-door location rules (front-facing restrictions in some cities).
- Confirm WSEC 2021 path: prescriptive vs. performance.
- Confirm IRC fire separation requirements for attached ADUs.
3 · Utilities
- Locate existing side sewer; CCTV inspect if >40 years old.
- Confirm water meter size — 5/8" may require upsize for second unit.
- Confirm electrical service capacity (200A panel typical baseline).
- Gas service: confirm meter location and BTU capacity if gas appliances planned.
- Verify stormwater requirements above new impervious threshold.
- Pre-pay system development charges (SDC) if budget timing matters.
4 · Design & engineering
- Choose pre-approved plan vs. custom (saves 6–12 weeks in many cities).
- Geotech report if slope > 15% or in landslide overlay.
- Structural calcs stamped by WA-licensed PE.
- Energy calcs (REScheck or COMcheck per WSEC).
- Manual J load calc for HVAC sizing.
- Title-24 / WSEC compliance documentation.
- Site plan with grading, drainage, erosion control.
5 · Contract & contractor
- Verify WA L&I license, bond, and insurance on the contractor (look up lni.wa.gov).
- Confirm general liability coverage minimum $1M.
- Workers' comp account in good standing.
- Written contract with scope, schedule, payment milestones, and change-order process.
- Allowances itemized — finishes, fixtures, appliances.
- Clear lien-release procedure tied to each payment.
- Final retainage held until punch list complete.
6 · Financing
- Pre-qualified construction loan or renovation loan in place before permit.
- Appraisal-based draw schedule reviewed with lender.
- Confirm draw inspection timeline matches the contractor's schedule.
- 10–15% contingency reserved outside the contract budget.
- Property tax reassessment estimate from County Assessor.
- Confirm insurance carrier covers builder's risk during construction.
7 · Schedule & logistics
- Confirm permit issuance estimate from city (use our Permit Timeline tool).
- Lead-time check on long-lead items: windows, panel upgrade, custom cabinetry.
- Site logistics plan: material staging, dumpster, portable toilet, neighbor notice.
- Pre-construction meeting with city inspector if required.
- Final neighbor notice for projects adjacent to shared driveways or fences.
Want us to run this for you?
Golden State runs this checklist as part of every free 30-minute consultation — we'll flag the items that apply to your address.