Multifamily and Duplex Properties for Sale in Los Altos Hills: Zoning and Rent Rules

What multifamily in Los Altos Hills looks like

Los Altos Hills has historically had almost no apartments. Its housing is single-family homes on lots of an acre or more, and income property usually means a main house with an accessory dwelling unit, a junior ADU, or an SB 9 unit. That is beginning to change: in late 2025 the Town adopted multifamily zoning standards for designated sites to meet its Housing Element, at densities far above anything else in town. For a home with one to three added units, read financing 2-4 unit properties; for a new apartment project on a designated site, see apartment building loans.

Where the zoning allows it

The multifamily standards. Article 16 was adopted by Ordinance 621 on December 9, 2025 and took effect January 8, 2026. Units average 750 square feet (1,000 for senior or assisted living), range from 350 to 2,000 square feet, and need 1.0 to 2.0 parking spaces by bedroom count plus 0.2 guest spaces. Front setbacks are 60 feet. Buildings cannot go on slopes over 25%, within 100 vertical feet of a ridgeline or within 50 feet of a creek, and hilltop structures are capped at 19 feet. Every project needs a site development permit, with Planning Commission review against the Multi-Family Objective Design Standards. Projects with at least 20% lower-income units on sites the Housing Element identifies for lower-income housing get ministerial review.

SB 9 in the hills. SB 9 applies only in R-A and excludes historic resources, very high fire hazard severity zones, floodways and protected habitat. A standard SB 9 unit is capped at 900 square feet and 16 feet; with the code’s development incentives, the cap rises to 2,000 or 3,000 square feet depending on lot unit factor. On a parcel that has not been split, a primary home plus SB 9 unit, an ADU and a JADU are all allowed. On lots created by an SB 9 split, ADUs and JADUs are not. See our SB 9 lot split guide.

ADUs. ADUs are accessory uses in R-A under Article 14, which we did not review in detail. See our ADU investment guide.

Rent rules: state law only

The Town has no rent stabilization ordinance. The Attorney General’s rent cap page, updated July 16, 2026, puts Santa Clara County in All Other Counties, with covered units capped at 8.6% for increases starting August 1, 2026 through July 31, 2027, after 7.7% the prior year. Its local ordinance chart lists only San Jose and Mountain View in the county. In Los Altos Hills, most rentals are single-family homes and ADUs, many of which can be exempt from AB 1482’s cap if owned by an individual and given the required notice; multifamily units in new Article 16 buildings would generally be exempt for their first 15 years. Confirm each unit’s status. See our AB 1482 guide and just cause eviction guide.

Los Altos Hills rental property rules

• SB 9 rentals. SB 9 units can be rented separately, but not for fewer than 31 days and never as short-term rentals.
• Short-term rentals. Under Article 12, adopted by Ordinance 575 in 2018, a short-term rental needs a Town license, the property must contain the owner’s primary residence used at least 270 days a year, and only one unit per property may be rented short term. Three validated nuisance violations lead to revocation.
• Employee housing. Employee and farmworker housing under state Health and Safety Code provisions is a permitted primary use in R-A.
• Transfer tax. The Town’s real property transfer tax is 27.5 cents per $500, administered by the County Recorder; confirm how it combines with the County tax in escrow.

Septic, slopes and building issues

Septic capacity is the practical limit on adding units in much of town. Under the Town’s sewage disposal article, new homes and major additions must connect to sewer when a main is within 200 feet of the property line, unless gravity flow is not possible; otherwise a private system is required, reviewed by the County Health Officer. For SB 9 splits, each new parcel must connect to sewer or have an onsite wastewater system fully inside its own boundaries, approved by County Environmental Health. Slope also matters: maximum floor area falls from 6,000 to 5,000 square feet per lot unit factor as average slope rises to 30%. Older homes converted to multiple units should be reviewed for seismic retrofit needs, and any future building of three or more units with elevated balconies will need SB 721 inspections.

Underwriting a Los Altos Hills income property

1. Confirm the zone: R-A, MF, MFO or a future FMFO site.
2. For a house with added units, calculate the lot unit factor, remaining floor area and development area.
3. Confirm sewer availability or septic capacity with County Environmental Health records.
4. Check each unit’s AB 1482 status and model covered units at or below 8.6%.
5. Treat SB 9 units as 31-day-plus rentals only; collect leases and estoppel certificates.
6. Rebuild expenses with reassessed taxes and septic maintenance in our rental property analysis.

Questions people ask

Sources & notes

1. Los Altos Hills Title 10, Article 5, R-A standards
2. Title 10, Article 7, R-A uses
3. Title 10, Article 16, Multi-family development standards
4. Title 10, Article 15, SB 9 objective standards
5. Title 10, Article 12, Short-term rentals
6. Title 6, Chapter 4, Article 1, Sewage disposal
7. Title 3, Chapter 5, Real property transfer taxes
8. California Attorney General, rent caps

Note: We did not identify which parcels are mapped MF or MFO, and did not review the ADU article or the Housing Element. AB 1482 exemption comments are general.

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

Related: Los Altos Hills real estate guide · Commercial real estate in Los Altos Hills · Multifamily investing guide · Investor services