The parcel checker adds Renton, Kent, Redmond and Federal Way — and four cities where an ADU is not allowed at all

The lot checker now covers seven King County cities instead of three. Getting there meant re-curling every candidate city zoning service against real single-family parcels drawn from the county's own records — the registry we had been carrying listed ten layers that a delegated research agent had reported but explicitly refused to vouch for. All of them answered, and all agreed with the county assessor on twelve of twelve sampled parcels; two cities missing from the registry entirely, Auburn and Federal Way, were tracked down and added. Renton's zoning turned out to be a group layer with one sub-layer per zone, which cannot be queried the ordinary way at all. The harder half was deciding not which zone a parcel is in, but whether that zone permits an ADU. Our corpus phrases that as prose — Auburn's 'lots meeting the zone's minimum lot size', Renton's 'in the lower-density zones' — never as a list of districts, and guessing is precisely what once put an invented Bellevue zone code into our own test suite. So we read the four cities' land-use tables directly. Two results are worth knowing if you own multifamily-zoned land: Renton's table leaves the accessory-dwelling row blank in RMF, RMF-2 and RMH, and Federal Way's multifamily chapter states outright that accessory dwelling units are not permitted. An ADU is a single-family-zone right in both cities. Redmond is the opposite — it permits ADUs across neighbourhood multifamily, mixed-use and downtown zones alike. Where a rule turns on the zone and we now know the zone, the checker resolves it: Renton's side setback is 25 feet in RC and R-1, 5 feet in R-4 through R-8, and 4 feet in R-10 and R-14, and it will tell you which one is yours. Where a figure we verified belongs to one zone and your parcel is in another, it says so rather than restating the number as though it governed.