What would Highland's proposed ADU ordinance change?

If you’re buying a Highland property with room for an accessory dwelling unit, or selling one with ADU potential, sewer service could affect the application before plans get very far. Proposed Ordinance No. 485 would change how the city handles that initial question.

The proposal would let the city accept an ADU application on a property without public sewer and send the sewage-disposal question to the appropriate agency. That would open an application route. It would not establish that the property qualifies.

There is also an unresolved status question: final adoption has not been verified as of October 27, 2026.

F. kept turning a key ring in his hand as we stood in the garage and discussed an ADU conversion. He wanted to know whether it was worth continuing to explore, so I opened the sewer information with him. The records showed no public sewer connection. Under the proposed ordinance, that detail would no longer stop an ADU application at intake, but the sewage-disposal decision would still belong to the appropriate agency. We had a reason to examine the proposal closely, while the property’s eligibility and the ordinance’s final adoption remained unestablished.

Has Highland adopted the ordinance?

Final adoption of Ordinance No. 485 is unverified, although the City Council introduced it by a 5-0 roll-call vote on September 8.

The approved September minutes appear in the official October 13 agenda packet. The ordinance would amend Municipal Code Section 16.44.180 for consistency with Senate Bill 543, Assembly Bill 154 and Senate Bill 9, while continuing Housing Element Program 12.

The October agenda listed the second reading as consent-calendar item 10. Staff recommended adoption as submitted and reported that no modifications had been made at the September hearing. But no official October minutes or action record confirming adoption was available as of October 27.

For your transaction or application, keep the proposal separate from the current codified section. Ask Planning to confirm final action and the applicable text before relying on a proposed provision.

What would change for a property on septic?

The proposed process would allow intake of an ADU application without public sewer, leaving the sewage-disposal decision to the appropriate agency.

According to the approved September minutes, staff previously rejected such applications at intake. Under the proposal, the city would defer to East Valley Water District and the California State Water Resources Control Board system identified in those minutes as CalWATRS. The question would be whether sewer connection is feasible or a septic permit can be issued.

The city would proceed if the appropriate agency approves and would not approve if that agency determines the use is not permitted. An adequate sewage-disposal system would still be needed.

Staff told the council it turns away about five such applications per year and that CalWATRS had approved one septic-system ADU. Those are recorded staff statements, not a citywide study or a forecast for your property.

For a separate local example of why sewer and septic questions need careful checking, see La Canada Flintridge septic and sewer connection. Its local rules should not be applied to Highland.

How would the fire-zone wording change?

The proposed planning-review text would prohibit ADUs in areas Cal Fire designates as a “very high fire hazard severity zone” or “high fire hazard severity zone.”

That replaces the generic wording “high fire severity zone.” The distinction matters because the proposal names the agency’s designations and specifies both categories.

It does not establish that every Highland property in a fire zone receives identical treatment under every ADU pathway. Ask Planning which route applies to the parcel and how the cited restriction affects that route.

A seller can also review the property’s hazard information alongside natural hazard disclosure reports. Keep the designation question separate from property work discussed in wildfire hardening; neither discussion establishes ADU eligibility.

What size and parking limits would remain?

A planning-review ADU would remain limited to one on a residentially zoned lot with a proposed or existing primary dwelling, with size and parking standards still applying.

Attached ADU area generally could not exceed half the primary dwelling’s gross floor area. The exception protects an 850-square-foot unit, or a 1,000-square-foot unit with more than one bedroom, where the half-area limit would prevent it. Under the planning-review standards, an attached or detached ADU with two or more bedrooms is capped at 1,200 square feet.

The general parking requirement is one off-street space, subject to listed exceptions. These include being within one-half mile walking distance of public transit, conversion within an existing dwelling or accessory structure, certain parking-permit areas and a nearby car-share space. A concurrent application with a new primary dwelling can also qualify where other criteria are met.

A garage or carport conversion does not require replacement of removed parking while the legal ADU use continues. For broader context before checking the parcel-specific route, read ADU rules.

What would the proposal require for a JADU?

A junior accessory dwelling unit would need to be between 150 and 500 square feet, with an efficiency kitchen and an exterior entry.

No added parking would be required. Fire sprinklers would be required only where the primary dwelling requires them; creating the JADU would not trigger sprinklers for the existing dwelling.

The proposed owner-occupancy wording is conditional. Owner occupancy of the primary dwelling would be required only if the JADU shares sanitation facilities with it. That detail deserves attention when comparing layouts.

ADUs and JADUs approved under the section may be rented only for terms of 31 days or longer. Keep that limit in mind before describing a proposed unit’s rental possibilities.

Which documents should an owner prepare?

Before an ADU building permit, the owner must submit water and sewer-disposal service-availability letters to the building official.

The city’s current ADU/JADU submittal packet separately lists an ADU approval letter, building permit application, plans and calculations, a fire-flow test where applicable, and septic/OWTS approval where applicable. It also says a separate address will be assigned for the ADU/JADU.

Consider an owner comparing an ADU with a JADU on a Highland property without public sewer. Under the proposed process, the ADU application could reach intake, but the sewage-disposal question would still need agency approval. The owner would also need to establish which planning route applies and obtain the service-availability letters before an ADU building permit. Choosing the smaller JADU would bring a separate question into the layout discussion: whether it would share sanitation facilities with the primary dwelling.

These documents serve different steps. An application, service letter, fire-flow test or sewage-disposal approval does not guarantee a building permit.

Could an owner appeal an incomplete application finding?

The proposal would create an appeal to the Planning Commission for an incompleteness determination under Government Code Section 66317.

The commission would issue a written decision, and that decision would be final. This is an appeal route for whether the application is complete. It should not be described as assurance of project approval.

If you receive an incompleteness determination, ask Planning how the proposed appeal provision applies and which documents remain outstanding.

The short version

Highland’s proposal would change septic application intake, clarify fire-zone wording and revise other ADU/JADU provisions, but final adoption remains unverified.

For a buyer or seller, the practical next step is to confirm the ordinance’s status, the property’s application pathway and the sewage-disposal decision. Describe ADU potential with those unresolved conditions attached.

To put your property’s plans in the context of a possible sale, start with the home value tool.