Multifamily and Duplex Properties for Sale in Kensington: Zoning and Rent Rules

What multifamily in Kensington looks like

Kensington is a compact, unincorporated hillside neighborhood of mostly single-family homes between Berkeley and El Cerrito. Apartment buildings are scarce. Income property here usually means:

• A home with a legal ADU or JADU, often built into a downhill lower level
• An older house split into two units, where permits support it
• A few small multi-unit buildings near the Arlington Avenue and Colusa Circle business areas
• Two-unit projects under the county’s SB 9 rules

For financing, see financing 2-4 unit properties and apartment building loans.

Where the zoning allows it

Contra Costa County zones Kensington. Most lots are in single-family districts, and the whole community is covered by the -K Kensington Combining District.

How -K review works. Chapter 84-74, which traces to Ordinance 2004-46, sets a public hearing threshold for gross floor area that scales with lot size:

• Lots under 5,000 square feet trigger a hearing above half their area.
• A 6,000-square-foot lot triggers one above 2,700 square feet.
• Lots of 20,000 square feet or more trigger one above 22% of their area.

Below the threshold, neighbors within 300 feet still get notice and can request a hearing within 34 days. At a hearing, the zoning administrator weighs views, privacy, light, parking and bulk, and can require sun-shadow studies. Recent notices show the system in use: 279 Colusa Avenue went to hearing over a 2,800-square-foot threshold in 2025, and 153 Lawson Road over a 3,600-square-foot threshold in 2026.

ADUs are exempt from -K review. ADUs and JADUs under Chapter 82-24 are exempt from -K review, but get smaller size caps in Kensington. The county’s 2025 ADU rules, from Ordinance 2025-07, cap Kensington ADUs at 850 square feet for one bedroom and 1,000 square feet for more. Height is set by the state ADU statute. ADUs cannot be rented for less than 30 days. See our ADU investment guide.

SB 9. County Chapter 88-36 allows two units on single-family lots in Census urbanized areas that clear state exclusions, including historic resources. Each unit needs one parking space unless the lot is within half a mile of major transit. No ADU is allowed on a lot created by an urban lot split. Kensington’s hills include high fire hazard areas, which state law may exclude, so check mapping first. SB 9 projects are not exempt from -K review. See our SB 9 lot split guide.

Rent rules: state law only

Kensington is unincorporated and has no local rent cap. The Attorney General’s chart lists only Antioch, Concord and Richmond in Contra Costa County. Covered Kensington units follow the state cap for the San Francisco area: 6.3% from August 1, 2025, and 8.8% from August 1, 2026 through July 31, 2027. Berkeley’s rent ordinance does not reach Kensington, even though many Kensington homes have Berkeley mailing addresses. Single-family homes owned by individuals can be exempt with the required lease notice. See our AB 1482 guide and just cause eviction guide.

Kensington rental property rules

• Short stays. ADUs, JADUs and SB 9 units must be rented for at least 30 days. A main house can be a short-term rental only with a county permit under Chapter 88-32, which caps non-hosted rentals at 90 days a year.
• No county registry found. We found no county rental registry or inspection program for Kensington.
• KCSD services. The Kensington Community Services District provides police, parks and solid waste collection, according to LAFCo.

Special taxes, hillsides and building issues

• Police tax is per parcel. The KCSD’s 2026–27 police tax is $486.45 per multi-unit residential parcel and $324.30 per single-family parcel. Because it is per parcel, not per unit, it costs less per door on a multi-unit property.
• Fire tax. A separate fire special tax, inherited when the Kensington Fire Protection District was dissolved and annexed into the KCSD, is also on the roll.
• Hillside construction. Steep lots often require variances. One 2026 hillside home needed three setback variances and a permit to remove two protected oaks, according to its KMAC notice.
• Older homes. Many Kensington homes date from the 1920s to 1950s. Unit conversions in older houses warrant a seismic retrofit review. SB 721 applies only to buildings of three or more units.
• Transfer tax. Only the county’s $0.55 per $500 applies.

Underwriting a Kensington income property purchase

1. Confirm the zoning, that the parcel is unincorporated, and permits for any existing second unit.
2. Calculate the -K floor-area threshold before planning any addition.
3. For an ADU, plan around the 850 or 1,000 square foot Kensington caps.
4. Check fire hazard mapping before relying on SB 9.
5. Include KCSD police and fire taxes in operating costs, and request estoppel certificates for tenants.
6. Model returns with our rental property analysis guide.

Questions people ask

Sources & notes

1. County Ordinance Code via GoCodebook: Chapter 84-74 (-K), D-1, N-B, Chapter 82-24, Chapter 88-36, Chapter 88-32
2. KMAC notices: 279 Colusa Ave., 153 Lawson Rd., Highgate Ct.
3. Contra Costa LAFCO, Directory of Local Agencies, Section 3
4. KCSD Resolution 2026-11 and Resolution 2026-12
5. California Attorney General, rent caps
6. Contra Costa Clerk-Recorder, Documentary Transfer Tax

Note: We did not confirm which parcels in Kensington are zoned D-1 or multifamily, fire hazard zones, or the fire tax rates. Whether -K review applies to SB 9 units is our reading of the -K exemptions list, which names ADUs but not two-unit developments.

General information, not legal or tax advice. Last reviewed October 2026 by Matthew Martinez.

Related: Kensington real estate guide · Commercial real estate in Kensington · Multifamily investing guide · Investor services