Elevation Certificate in Seattle, WA

What the Certificate Records

An elevation certificate is the FEMA form that documents how high a building sits relative to the flood elevation mapped for its location. The surveyor measures the lowest floor, the top of the next higher floor, the lowest adjacent and highest adjacent grade, the elevation of machinery and equipment such as furnaces and water heaters, and details of any crawlspace flood openings, and records them with photographs of the building. Insurance agents use it to rate flood coverage, lenders and buyers use it to understand risk, and permit reviewers use it for new construction and substantial improvements in a mapped special flood hazard area.

River Valleys, Not Ocean Beaches

Flood exposure around Seattle is mostly riverine and concentrated in a few valleys. The Green River valley running through Kent holds large amounts of industrial and residential property behind levees, and the flood maps reflect how those levees are credited. The Cedar River passes through Renton on its way to Lake Washington. In Seattle, the lower Duwamish around South Park and Georgetown carries mapped flood zones, and some low shoreline pockets along Puget Sound do too. Around Redmond, the Sammamish River and Bear Creek corridors have their own mapped areas. Lake Washington itself is held at a controlled level by the Ballard Locks, so lakefront risk in Kirkland or Mercer Island is a different conversation than it would be on an uncontrolled lake.

Map, Datum and Building Diagram

Each certificate is tied to the effective Flood Insurance Rate Map for the address, and to the vertical datum that map uses, generally NAVD 88 on current maps, though older flood studies and building records may reference NGVD 29. Getting that wrong shifts every number on the form. The building is classified by one of FEMA's building diagrams - slab on grade, crawlspace, basement, elevated on piers - and choosing the correct one matters as much as the measurements themselves. We record which map panel and datum were used so the certificate can be understood years later.

What It Cannot Promise

A certificate reports measurements; it does not guarantee a lower premium, and we will not predict the rating before the fieldwork is done. For buildings being designed or raised, a topographic survey supplies the grades the design is based on, and an as-built survey can confirm finished elevations after construction. Commercial buyers often request flood zone determination as part of an ALTA/NSPS survey as well.

How long does it take? The site visit is short. Confirming the effective flood map panel and completing the form correctly is where the time goes.

Frequently Asked Questions