One bid is much lower
Check exclusions and drawing revisions before deciding.
Snohomish and King counties
The ADU and addition bid comparison worksheet
A low total can hide a smaller scope. Compare estimates only after identifying which drawings, assumptions, allowances, and responsibilities each one uses. This worksheet is a way to organize a decision, not a cost estimator.
Prepared by NW STYLE HOMES 1 LLC · September 5, 2026
Establish one comparison basis
Record the drawing revision, project description, intended use, and finish selections sent to each bidder. Ask every estimator to identify assumptions. If one proposal uses a conceptual sketch and another uses reviewed plans, keep that difference visible. Do not treat those totals as prices for the same project.
Build an included, excluded, unresolved table
Make rows for design, engineering, permits, site preparation, foundations, framing, roofing, utilities, interiors, and closeout. For each proposal, record what is included, excluded, or awaiting investigation. Write down who owns each missing item. An exclusion does not disappear because the proposal total looks complete.
Compare allowances and changes
Identify provisional material amounts and other allowances. Ask what labor, tax, delivery, or installation is included in each and how the final amount will be reconciled. Request the process for written change authorization. Compare the scope behind each number without inventing a percentage contingency that ignores the actual project risks.
Check schedule and handoff assumptions
Separate design readiness, jurisdiction review, procurement, construction, and inspection milestones. Ask which commitments depend on another party. Define the closeout documents and remaining work list. Confirm the contractor entity and registration with L&I, and discuss the written agreement before accepting a proposal; this worksheet is not a contract review.
Bring this to the first conversation
- Same plan revision for all estimates
- Included/excluded/unresolved comparison rows
- Allowance details and change process
- Milestones and closeout responsibilities
Keep a copy of this list with your project notes. Share only the records needed to understand the work; omit unrelated personal or financial information.
Local review and source links
Use the office for the actual property jurisdiction. A postal city name does not establish the reviewing authority. These official resources were checked September 5, 2026; confirm current requirements with the authority before applying.
This is general project preparation, not a site inspection, design, permit determination, or fixed-price proposal.
Choose your next step
Finish choices are incomplete
Compare what each allowance actually includes.
A completion date is essential
Identify dependencies and written schedule assumptions.
Discuss your project
Construction inquiries are limited initially to Snohomish and King counties. The Washington name describes the brand, not statewide field coverage. The planning guide can help organize questions elsewhere, but local rules and actual contractor availability must be verified separately.
Review the service scope, then request an estimate on this site. Include the decisions you have already made and the questions still open.