South Park

The South Park Historic District (Local Register) covers the blocks from A Street to about Elm Street between 28th and 31st streets; the Golden Hill Historic District is just south of A Street. On a single-family lot in a designated historic district, new development needs a Site Development Permit, decided through the City's Process Four, unless it qualifies for an exemption. Exempt work still needs a regular construction permit.

Exemptions include minor alterations, and new construction that keeps the district's character, when the work follows the Secretary of the Interior's Standards; and larger changes to a structure that is not significant to the district, also following those Standards. The rules apply to the whole lot, not just the house. The public map shows each district's outline, not whether a given home is a contributing resource — ask the City early.

Yes. Most houses here are old enough to trigger it: 31 of the 51 single-family homes sold in South Park from January 1, 2025 through November 10, 2026 were built before 1940. For a permit on any parcel with a structure 45 or more years old (outside areas the City has exempted), the City decides whether a site-specific historic survey is needed — within 10 business days for a construction permit, or 30 calendar days for a development permit. A survey is required when a historical resource may exist and the project is a substantial alteration. Interior-only electrical or plumbing work, in-kind roof repair, in-kind foundation repair (except decorative block or cobblestone foundations) and a rear-yard pool are exempt from this review.

Separately, the City's Historical Resources Board can designate individual homes after a public hearing; owners get notice at least 10 business days before. The City's map shows roughly 60 individually designated historical resources in South Park.

The Mills Act lets the owner of a City-designated historic property sign a contract with the City to maintain and restore it, in exchange for a property tax assessment set by the County Assessor under a state formula. The City says savings depend on the property's location, size and comparable rents, and that long-held homes with already-low taxes may not benefit.

The home must be designated by the City — listing on the National or California Register alone does not qualify — and the City says homes in established local historical districts can apply, except in redevelopment areas. Applications are due March 31; the home must have been designated by December 31 of the year before; and the application needs a 10-year work plan showing the tax savings going back into the house. The contract runs 10 years and renews every year.

Usually, yes. On a lot with a single-family home, the City allows one ADU inside the house or an existing accessory structure such as a garage, plus one new attached or detached ADU, plus one junior ADU of up to 500 square feet inside the house or an attached garage. A new attached or detached ADU can be 150 to 1,200 square feet. ADU floor area counts toward the lot's floor-area limit, but one ADU of 800 square feet or less is allowed even where floor-area, lot-coverage or front-setback limits would block it.

Detached ADUs on single-family lots can be up to two stories, within the zone's height limit. Side and rear setbacks for an ADU 16 feet tall or less are zero outside High and Very High Fire Hazard Severity Zones, and 4 feet inside them. No parking is required for an ADU here, and a garage converted to an ADU does not have to be replaced. ADUs cannot be rented for less than 31 days; owners don't have to live on site, except with a junior ADU. South Park is outside the Coastal Overlay Zone, so the City's current ADU rules apply. On a lot in the historic district, the historic review rules above still apply to new construction.

It lets an owner build extra “bonus” ADUs in exchange for affordable ADUs rented to very low, low or moderate income households. Inside a Sustainable Development Area (near major transit), each affordable ADU earns one bonus ADU; outside one, the cap is one bonus plus one affordable ADU. On a single-family lot, all ADUs and junior ADUs together are capped by lot size: 4 on lots of 8,000 square feet or less, 5 up to 10,000, and 6 above that. Floor area is figured on no more than 8,000 square feet of lot.

Affordability is set by an agreement with the San Diego Housing Commission — 10 years for very low or low income, 15 years for moderate — with a penalty of at least $10,000 per ADU per month for violations. Bonus and affordable ADUs need fire sprinklers, and one parking space each outside a transit priority area. The program isn't available in the RS-1-1 to RS-1-4 and RS-1-8 to RS-1-11 zones unless the lot is in a High or Highest state opportunity area and planned Residential. In High and Very High Fire Hazard Severity Zones, the lot must front an improved public street with two evacuation routes and cannot be on a cul-de-sac. Canyon-edge lots may be in a Very High Fire Hazard Severity Zone on the City's map — most South Park sales from January 1, 2025 through November 10, 2026 were.

A transit priority area is land within half a mile of an existing or planned major transit stop. On a lot even partly inside one, the City requires no off-street parking for a single-family home. On the City's map, all 52 homes sold in South Park from January 1, 2025 through November 10, 2026 were inside a transit priority area.

SB 9 duplexes and lot splits are not available on a lot in a designated historic district or with a designated historical resource. That rules out SB 9 on every lot inside the South Park Historic District. The City's Complete Communities Housing Solutions program — extra floor area for apartment and mixed-use projects that include affordable homes and neighborhood amenities — applies only in Sustainable Development Areas on sites zoned or planned for at least 20 homes per acre, so it matters for corridor and apartment sites, not single-family lots. It does not apply inside designated historic districts here.