Higher Lot Coverage to Boost Density

Under revised rules, Snohomish County could allow increased lot coverage and more flexible design in parts of the county's unincorporated urban growth areas. As reported by Stephen Fesler in The Urbanist, "county planners principally hope that the code amendments will solve lot coverage mismatches between zoning types, allow more flexible building and site design, and help development proposals reasonably achieve allowed zoning densities."

Lot coverage dictates how much of a lot can be covered by structures and has a major impact on how much usable square footage a lot can hold. Although sometimes associated with stormwater management and drainage, county planner Janet Wright addressed those concerns, stating in a briefing to the County Council "our drainage codes address mitigating stormwater runoff from…impervious surface areas and our code requires that projects implement low-impact development strategies where feasible." Wright also explained that "the current LDMR lot coverage maximum is unique and inexplicably lower than lower-density residential zones" and that increasing lot coverage "could bring more harmony of development patterns."

While the return on investment will ultimately drive site utilization, proponents of higher lot coverage predict that higher limits will "ensure that more projects fully use allowed zoning densities." The proposal is headed to a public hearing on March 3rd.