Residential Small Lot (RSL) zoning

MISSING MIDDLE HOUSING — SMART GROWTH — COMMUNITY ARCHITECTURE

SEATTLE, WASHINGTON

Residential Small Lot is a new zoning designation in Seattle found in urban villages of about 6,700 lots.

When Seattle proposed a new zoning designation, Residential Small Lot (RSL), CAST generated an in-depth analysis that illustrated the types of development the zoning code would allow, and how it would affect existing neighborhoods.

We created a courtyard apartment, duplex, fourplex, and cottage cluster designs that explored the possibilities with the code's FAR, lot coverage, setbacks, and maximum unit size provisions.

The analysis also led to a dozen recommendations for modifying the code to reduce adverse consequences not originally envisioned by the code writers, many of which were included in the final legislation.

As part of this effort, CAST ran a series of public seminars in neighborhoods subject to the new code for interested residents to understand how RSL might slowly alter the character of their streets. CAST is closely associated with efforts to improve housing affordability through increasing the “missing middle” moderate density infill within existing neighborhoods.

Green Design: Green Zoning