Steilacoom, WA: ADUs, septic or sewer, land prices and hazard areas

Steilacoom, WA ADU rules: can I build an ADU?

2,580 of the 3,028 lots in Steilacoom (85%) are zoned for houses inside an urban growth area. On those lots, Washington's HB 1337 requires the city or county to allow at least two accessory dwelling units (ADUs). Another 277 lots are outside the urban growth area, where Pierce County's own ADU rules decide.

Steilacoom, WA septic or sewer: septic records and sewer mains

50 of the 3,028 lots in Steilacoom (2%) have septic records on file with the Tacoma-Pierce County Health Department. 0 lots are inside a Pierce County sewer service area, and 2,729 are within 300 feet of a sewer main on the county's sewer map.

Steilacoom, WA land prices: vacant land and home sales

Vacant land in Steilacoom sold for a median of $298,485 per acre across 19 sales since November 1, 2023. Homes sold for a median of $625,000 across 257 sales. 3 new homes were permitted on its unincorporated lots since November 1, 2021. The city issues its own permits, which are not in our data yet.

Steilacoom, WA flood zones, landslide and wetland areas

Of the 3,028 lots in Steilacoom, 335 touch a mapped landslide hazard area, 146 an erosion hazard area, 94 a flood area and 118 an inventoried wetland, on Pierce County's maps.

From the Pierce County Assessor-Treasurer, the county's zoning, sewer, hazard and growth-area maps, and the Tacoma-Pierce County Health Department. Records as of November 7, 2026.

How these numbers are worked out · Guides

Other communities in Pierce County