3,407 of the 4,497 lots in Sumner (76%) 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 376 lots are outside the urban growth area, where Pierce County's own ADU rules decide.
436 of the 4,497 lots in Sumner (10%) have septic records on file with the Tacoma-Pierce County Health Department. 601 lots are inside a Pierce County sewer service area, and 0 are within 300 feet of a county sewer main.
Vacant land in Sumner sold for a median of $155,072 per acre across 16 sales since October 1, 2023. Homes sold for a median of $550,000 across 389 sales. 35 new homes were permitted on its unincorporated lots since October 1, 2021. The city issues its own permits, which are not in our data yet.
Of the 4,497 lots in Sumner, 387 touch a mapped landslide hazard area, 226 an erosion hazard area, 927 a flood area and 83 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 October 2, 2026.
How these numbers are worked out · Guides