Planning commission reviews draft objective design standards for ADUs, citing tree protection and privacy concerns

The Carmel-by-the-Sea Planning Commission on May 20 reviewed an administrative draft of objective design and development standards (ODDS) for accessory dwelling units, a consultant-led effort intended to provide objective, ministerial design rules that comply with state ADU law.

Consultant Tony Perez, leading the Opticos Design team, told commissioners the draft centers on three principles developed from earlier community meetings: ADUs should match the main house, be visually secondary on the lot, and be located to emphasize the primary residence rather than the accessory unit. The draft is organized into nine chapters covering site design, building form, facade details and administration, and addresses 13 specific topic areas shown to the public in prior workshops.

Perez said the ODDS are intended to be objective rules that can be applied ministerially and that theyre structured to work within state legal minima. "All new ADUs need to match the main house," Perez said, and he emphasized that the standards include measured variation to accommodate older houses where original materials or window sizes are unavailable. He described proposed building types (carriage house above a garage, attached ADU, detached ADU), footprint limits intended to keep ADUs human-scaled, and a new recommended "building entry area" requirement (porch, dooryard, terrace or stoop) intended to give ADU doors a defined, welcoming element.

Why it matters: Carmel must balance state ADU mandates requiring ministerial approval with local goals to preserve village character. Objective design standards are the citys mechanism to shape ADU appearance while still complying with state law.

What the draft would do
- Coordinate with existing code: the team said ODDS would be coordinated with Carmel Municipal Code provisions and related sections of Title 17 (planning) and Title 15 (lighting), and that building and fire codes would continue to govern safety standards.
- Address privacy and proximity: the draft includes guidance for windows and overlooks, including a 72-inch minimum window-sill height where new ADU windows align directly with windows on adjacent properties within about 15 feet, or alternatives such as angling windows away.
- Regulate roof and eave relationships: research for the draft identified perceptual thresholds for roof pitch, eaves and dormers; as an example, the team proposed dormer coverage guidance that the commission questioned.

Public and commissioner concerns
Residents and commissioners asked a mix of technical and policy questions in a lengthy Q&A and public-comment period. Key concerns raised:
- Site coverage and entry areas. Commissioners and public commenters asked whether the proposed building entry area would count against site coverage and how that would affect small lots. Staff said open porches are not floor area but that hard-surfaced entries typically count as site coverage and that the ODDS and the forthcoming ADU ordinance must be coordinated to resolve conflicts.
- Tree protection. Multiple commenters urged stronger protections for established trees and landscaping, warning that design standards should not encourage tree removal to fit ADUs on constrained lots.
- Second-story ADUs and privacy. Commissioners repeatedly requested clearer rules for second-floor ADUs (including carriage houses) and how the standards handle overlooking, privacy and whether an attached second-story ADU can exceed the existing residence height (staff said attached ADUs are set up not to exceed the existing residence in the current draft).
- Practical edge cases. Architects and property owners noted some draft provisions (for example, requirements to add windows or balconies for blank walls) could be impractical on lots with steep slopes or where a blank wall faces hillside with no view; the consultants said exceptions and ministerial waivers can be written to avoid nonsensical outcomes.

Representative quotes
"These three principles came out of community meetings one and two," Perez said, describing the foundation for the standards. "If these principles need to be updated or another one needs to be added, we're certainly open to that."
"Is the building entry area included in the total square foot of the ADU?" Commissioner Alborn asked. "No," the presenter replied, adding that the entry typically counts toward site coverage, a point staff confirmed.
"We need to make sure our document clearly distinguishes between ground-floor additions of ADUs and second-floor additions of ADUs to the primary residence," Commissioner Alborn said during discussion.

Next steps
Perez said staff and consultants will revise the administrative draft based on commission feedback and the team aims to publish a public review draft of the ODDS by mid-June, with additional planning commission and city council hearings planned in July through September. Staff also told commissioners the ODDS will need to align with a separate local ADU ordinance being drafted concurrently.

Authorities referenced in the hearing include the Brown Act, the Carmel Municipal Code, Title 17 and Title 15, and state ADU statutes governing ministerial approval and size/height minima. The commission asked staff to clarify statutory references (for example section 6632) where potential conflicts were raised.

The commission did not take a formal vote on the ODDS; the discussion was workshop-style and commissioners asked staff to return with refined language on entries, site coverage, tree protection and second-story privacy.