What you're paying for
Two deliverables, usually bundled:
- Boundary survey — the legal lot lines with monumentation. SDCI and SPU won't accept assessor maps, title-company sketches, or "old plat" data. Only a stamped survey by a Washington-licensed land surveyor (PLS).
- Topographic survey — grade contours, visible utilities, easements, and (per Seattle's tree code) every regulated tree with species, diameter, and drip line.
Combined cost in Seattle: $3,500 – $6,000 for a typical SF lot.
Why this comes first
Almost everything downstream depends on the survey:
- The architect can't draw a real site plan without grade and the legal property line.
- The arborist's tree inventory gets recorded onto the survey.
- The geotechnical engineer needs grade contours.
- SDCI plan review requires it on the permit submittal.
Skip topo and just do boundary, you save maybe $1,500 — and pay it back twice when the foundation has to get redesigned around grade reality.
How to hire a surveyor
- Verify the PLS license at WA DOL — Engineer & Land Surveyor Search.
- Get two or three quotes. Pricing in Seattle is fairly tight.
- Confirm in writing that the deliverable includes the regulated trees per current SMC 25.11 (species, DSH at 4.5 ft, drip line for each tree ≥ 6 inches DSH).
What the deliverable looks like
You'll get a stamped PDF (and usually CAD files for the architect) showing the legal lot, monumentation found or set, contours at typically 1-ft intervals, visible utilities, easements of record, and the regulated tree inventory.
Hand it to the architect, the arborist, and the geotech together. From here on, every decision lives on top of these lines.
Where this information came from
- SPU — Land Survey Requirements · retrieved April 22, 2026