Nevada City Council weighs raising ADU ministerial height limit to 20 feet

Nevada City staff on Wednesday presented a proposed zoning change that would raise ministerial accessory dwelling unit (ADU) height limits from 16 feet to 20 feet and outlined the next steps for public review.

Lisa, a city staff presenter, told the council the draft ordinance (2025‑06) would amend Nevada City Municipal Code section 17.72.026 to allow standalone ADUs up to 20 feet high under ministerial review and permit over‑garage ADUs up to 35 feet so long as they do not exceed the height of the primary structure. She explained how building height is measured — average stem‑wall/foundation plus wall height plus roof peak — and showed examples of ministerial ADUs built at under 14 feet and proposed designs approaching 18–20 feet.

“The change would be to allow for a taller height allowance for ADUs for a ministerially approved project,” Lisa said, adding that the proposal would keep the city’s objective design standards (including a 6:12 minimum roof pitch) intended to maintain compatibility with Nevada City’s historic character.

Staff cited accessibility as a motivating factor: one project designer told staff that a taller ADU would allow two adjacent interior rooms and easier, accessible circulation for occupants with disabilities. Staff noted that many local lots are sloped and require stem walls; a three‑foot stem wall can quickly push a building past the existing 16‑foot limit, making ministerial approval impractical for some designs.

City staff laid out a tentative schedule: the proposal had been reviewed by the Economic and Community Development committee and was scheduled for the planning commission on Sept. 18; a first reading at the council was slated for Sept. 24 and a second reading for Oct. 22 if it proceeds.

Council members acknowledged both benefits and tradeoffs. Supporters said the change could yield ADUs that better match local roof pitches and historic forms and broaden the number of projects eligible for ministerial (staff) approval, which reduces fees and processing time. Others raised concerns that taller ADUs on small lots could appear imposing, increase perceived massing, or create privacy issues by overlooking neighboring windows. Staff said objective design standards and site‑specific review would limit windows and reduced setbacks to avoid direct overlooking except where needed for safety or egress.

No formal ordinance adoption occurred at the meeting. Council provided direction to send the draft ordinance to the planning commission for review and public hearings; staff will return to council after the planning commission’s recommendation.

Why it matters: ADU rules affect how much and what type of new small‑scale housing can be added in established neighborhoods. Raising the ministerial height cap is intended to reconcile state ADU policy with Nevada City’s steep lots and architectural character while streamlining approvals for designs that meet objective standards.