Sandpoint staff proposes new lot‑coverage curve and slight RM density increase to ease ADU/multifamily development

Community Planning and Development Director Jason Welker told the Sandpoint Planning and Zoning Commission on Nov. 4 that staff is proposing to remove the city’s separate maximum building‑footprint standard and adopt a single impervious‑surface standard that would top out at roughly 70% on the smallest residential lots and scale down to about 35% on the largest lots.

Welker said the change is intended to simplify overlapping rules and give property owners more flexibility to add living space, including accessory dwelling units (ADUs), without changing setbacks or other dimensional standards. “There are only two ways to get affordable housing, density or subsidy,” Welker quoted Councilman Joel Esparrow as saying during a recent town‑hall discussion, and he used that framing to describe the amendment as a measured way to allow greater density where infrastructure already exists.

The staff proposal includes a stepped table that reduces allowable impervious percentages as lot size increases and a companion amendment to the RM (residential multifamily) development standards so that slightly larger buildings could, in some lot‑size bands, accommodate an additional dwelling unit. Welker said the table shown is a draft for discussion and that staff used in‑house GIS estimates rather than a commissioned data pull; he cautioned that the in‑house numbers are approximate.

Commissioners focused on three implementation questions: (1) whether a stepped percentage table could create anomalies at marginal lot sizes (a slightly larger lot allowing a smaller building), (2) whether road‑frontage requirements or lot size should govern multifamily unit allowances, and (3) how parking and snow‑storage requirements would affect real‑world development even if lot‑coverage rules change.

Commissioner Scott Torpey warned that the stepped approach could produce marginal oddities at bracket boundaries and suggested either a marginal (progressive) calculation or a smooth curve that is easy to administer. Welker said a single flat impervious standard would be simplest to administer but that staff can design a formula or table that planners and the public can use at the counter.

Commissioners and staff also questioned the role of a road‑frontage table in the RM zone. Welker noted frontage standards are commonly used for new subdivisions but said they can penalize deep infill parcels that have narrow street frontage; commissioners asked staff to evaluate whether frontage requirements should be adjusted, retained for new subdivisions only, or supplemented with an administrative review pathway.

Parking and snow storage were raised repeatedly. Welker summarized existing off‑street requirements from the zoning code (for example, he said, apartment units under 1,200 sq. ft. generally require one space per unit and larger single‑family homes often require two) and noted that site‑plan review triggers (typically four or more units) prompt a detailed review of snow‑storage areas, but the code lacks a quantitative snow‑storage standard for smaller projects.

Staff illustrated the practical implications with GIS maps showing many historic 25‑foot platted lots underlying larger assessor parcels and walked commissioners through a sample 0.36‑acre lot that in staff’s draft table could yield seven units, subject to parking, setbacks and building‑code constraints. Welker emphasized that property owners often must legally consolidate platted lots to build across historical lot lines because building‑code and fire‑separation rules depend on those lot lines.

Next steps: staff said it will return with refined percentage numbers (a 'smoothed' curve or alternative marginal approach) and with additional analysis of the road‑frontage table, parking triggers and whether to exempt certain existing deep lots or create an administrative waiver pathway. Welker said a public hearing will be required before any ordinance changes are forwarded to the City Council.

No formal vote was taken on the code changes at the workshop stage; commissioners generally signaled tentative support for modest adjustments but asked staff to 'sharpen the pencil' on the draft table and administration before scheduling a public hearing.