Planning Commission hears proposal to use gross area for R1 density; staff and commissioners flag environmental and infrastructure concerns

The Sammamish City Planning Commission received an introductory briefing on a proposal to change how residential density is calculated in the city’s R1 zone, including consideration of a pilot program that would use gross site area rather than net (constrained) area to determine the number of allowable dwelling units.

The change would raise the allowable number of dwelling units on sites that contain critical-area constraints by counting the full, gross parcel area when calculating density rather than subtracting wetlands, steep slopes, stream buffers and streets to arrive at a smaller net area. Robin Probsting, Associate Planner, told the commission: “This particular proposal asks to change the development regulations in the R1 zone only. It would change the density calculations so that gross area rather than net area is used to calculate how many units can be built.”

Commissioners were asked to provide feedback on selection and success criteria for a pilot program the City Council…