Bids, contracts and permits for Washington remodels and ADUs
How to get comparable bids, what to put in a written contract, when a permit is needed and where accessory dwelling units fit.
Large residential projects go wrong more often from unclear scope and permits than from bad workmanship. L&I's advice to homeowners is plain: get at least three written bids, compare them carefully, check references, get a written contract you understand and consider a performance bond on larger projects. Here is how to apply that.
Get comparable bids
Give each contractor the same written scope: dimensions, materials by brand or grade, fixtures, finishes, demolition, disposal and who is responsible for design drawings. Ask them to list allowances (amounts set aside for items you have not yet chosen) separately, and to list exclusions. A bid that is much lower than the others usually leaves something out.
Check the paperwork on every bidder
Verify the registration, bond and insurance for each bidder on the L&I tool. Note the disclosure statement: for residential projects of four or fewer units with a contract of $1,000 or more, the contractor must give you one before starting work (RCW 18.27.114).
What belongs in the contract
- Contractor name, business address and L&I registration number.
- Detailed scope and specification, drawings and allowances.
- Total price and how change orders are priced and approved in writing.
- A payment schedule tied to completed stages, and any retainage.
- Start date, completion target and what counts as substantial completion.
- Who pulls permits and schedules inspections.
- Lien release procedure at each payment.
- Warranty terms in writing.
Permits
Most structural, electrical, plumbing and mechanical work needs a permit from your city or county building department, and electrical permits often come from L&I. Cities also review zoning setbacks, critical areas such as steep slopes and shorelines, and trees. The permit belongs to the project; ask that it be pulled in the licensed contractor's name so that inspections and responsibility are clear, and keep the final inspection sign-off with your house records.
Accessory dwelling units
Washington has encouraged accessory dwelling units (ADUs, including backyard cottages and basement or garage conversions) in recent years, and cities such as Seattle and Bellevue publish their own ADU rules, fees and permit steps. If you are building one, use a builder with ADU experience, ask to see a finished project and get the city's pre-application guidance before signing. Our sister site ADU Builder Index lists Seattle and Bellevue ADU builders with the same positive-only verification approach.
During the job
- Pay only for completed work, and collect lien releases.
- Approve every change in writing before it is done.
- Photograph work before walls close up.
- Do not let the final payment go until inspections have passed and punch-list items are done.
If you have a dispute
Try to resolve it in writing with the contractor first. Then contact L&I about the registration, and consider whether the bond deadlines in RCW 18.27.040 apply to you. For an unregistered contractor, remember that they may be barred from suing for payment under RCW 18.27.080, and that L&I takes reports about unregistered work.
This is general information and not legal advice.