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

What multifamily in Cotati looks like

Cotati’s rental stock includes duplexes and small "plex" buildings, garden apartments, mixed-use buildings downtown, newer projects in the transit-oriented district, and mobile home parks. Three local rules shape investment: the city’s own neighborhood density districts, a growth management system that rations new dwelling permits, and rent stabilization that covers mobile home spaces but not apartments. For two to four units, read financing 2-4 unit properties; for larger buildings, see apartment building loans.

Where the zoning allows it

Chapter 17.20 creates the districts and Chapter 17.24 sets their standards.

District	Purpose	Density (units per acre)	Height	Coverage and unit size
NM Neighborhood, Medium Density	Various multifamily types	8 minimum, 10 maximum	28 ft	55%; 80% of units under 2,200 sq ft
NU Neighborhood, Urban	All multifamily types at higher density	12 minimum, 15 maximum	35 ft	75%; 80% of units under 2,000 sq ft
CD Downtown Commercial	Homes or offices over ground-floor retail	12 to 15	35 ft, 50 with use permit	100%
CE and CG corridors	Mixed use	12 to 15	35 ft; 45 or 50 with use permit	80%
TOC Transit Oriented Community	Higher-density mixed use near transit	25 to 35; FAR 1.0 to 3.0	45 ft, 55 with use permit	100%
CI Commercial/Industrial	Live/work among industrial uses	Up to 15	40 ft	80%
MHP and MHP-S overlays	Mobile home parks; senior parks	Per the overlay	—	Chapter 17.28

Minimum densities matter. Cotati sets minimums as well as maximums in NM, NU, CD, CE, CG and TOC. A buyer planning fewer, larger units on a redevelopment site may not get approval; the review authority can lower the minimum for mixed-use projects only where site constraints make it infeasible.

ADUs and SB 9. ADUs and JADUs are governed by Section 17.42.170 and are exempt from the growth management allocation. SB 9 applies in single-family zones under state law; we did not read Cotati’s implementing rules. See our ADU investment guide and SB 9 lot split guide.

Growth management: a cap on new dwelling permits

Chapter 17.52 requires a growth management allocation for every new dwelling’s building permit.

Annual cap. Up to 100 allocations a year, with at least 25 reserved for low and very low income units and 10 for single-family homes built by individual owners.
First come, first served. Allocations are issued with the building permit until the year’s cap is reached.
Carryover and expiration. Unused allocations carry over unless the council finds water or sewer capacity short, and an allocation expires three years after assignment unless construction is under way.
Shortages. The council can temporarily cut allocations during water or sewage treatment shortages.
Exemptions. Remodels that add no units, ADUs and JADUs, and specific plan units the council exempts.

For a developer, the cap is a timing risk; for an owner of existing units, it limits new competition.

Rent rules: state cap for apartments, local rules for mobile home spaces

Apartments and houses. The Attorney General’s rent cap page, updated July 16, 2026, does not name Sonoma County in a regional group, so covered units follow All Other Counties: up to 8.6% for increases from August 1, 2026 through July 31, 2027. Cotati is not on the AG’s chart of local apartment rent ordinances, and Title 19 of its code, as published through January 2026, contains no apartment rent or just cause chapter. State just cause and relocation rules govern covered tenancies. See our AB 1482 guide and just cause eviction guide.

Mobile home spaces. Chapter 19.14, adopted as Ordinance 680 in 1998 after the council put repeal of a 1979 voter initiative on the November 3, 1998 ballot, stabilizes space rents. Its findings counted three parks with 107 spaces.

Annual limit. The lesser of 100% of the CPI change, using the San Francisco-Oakland index, or 6%, no more than once in 12 months, with 90 days’ written notice.
Larger increases. Tenants representing 51% of affected spaces can petition within 21 days; an increase above 300% of the CPI change goes to arbitration automatically, with the owner bearing the burden of proof.
Vacancy. A new base rent is allowed only after a lawful vacancy, not on the in-place sale of a home.
Exemptions. Spaces under qualifying long-term leases are exempt if the lease and notices are filed.
Fees. Owners pay an annual administration fee and may pass through half to tenants.

Cotati rental property rules

Families with children. Chapter 19.08 bars discrimination against families with children in rentals.
Local preference. A city memo dated April 15, 2024 describes a local preference policy for deed-restricted affordable units, favoring people who live or work in Cotati, families in the Rancho Cotati school district, local tribal members and Sonoma State employees. It ties the policy to Program 4-1 of the Housing Element certified June 2, 2023.
Inclusionary housing. Chapter 17.31 sets affordable housing requirements and Chapter 17.32 density bonuses; check both before planning new units.
Short-term rentals. Stays of 30 days or less owe 10% transient occupancy tax under Chapter 3.12.
Transfer tax. The County Recorder lists Cotati as paying only the County’s $0.55 per $500, less assumed loans.

Utilities and building issues

Cotati runs its own water system and sewer program under Title 13, including a water shortage contingency plan and rules for sewer construction and connections. Older garden apartments should get a seismic retrofit review, and buildings of three or more units with elevated balconies need SB 721 balcony inspections.

Underwriting a Cotati multifamily purchase

Check unit count against NM or NU limits; extra units may be legal nonconforming.
Classify units under AB 1482 and model covered increases at or below 8.6%.
For a mobile home park, model space rents at the lesser of CPI or 6%, and review any long-term lease exemptions.
For new construction, confirm a growth management allocation is available and price the timing.
Collect leases, the rent roll and estoppel certificates.
Rebuild expenses with reassessed taxes and utilities in our rental property analysis.

Questions people ask

Does Cotati have rent control on apartments?

No. Cotati’s rent stabilization covers mobile home spaces only; apartments follow AB 1482, at up to 8.6% from August 1, 2026 for covered units.

How much can mobile home space rent rise in Cotati?

The lesser of the CPI change or 6% a year, unless an owner wins a larger increase through the petition and arbitration process.

Is there a limit on new apartments?

Yes. Growth management caps new dwelling allocations at 100 a year, with 25 reserved for low and very low income units. ADUs are exempt.

What density does NU allow?

12 to 15 units an acre, at up to 35 feet.

Are there minimum densities?

Yes, in NM, NU, CD, CE, CG and TOC.

Is there a city transfer tax?

No added tax; only the County’s $0.55 per $500.

Sources & notes

Note: We read the zoning chapters through GoCodebook’s October 2026 edition and Chapter 19.14 through Code Publishing, current through Ordinance 926 (July 9, 2024). We did not read Sections 17.42.170, 17.28, 17.31 or 17.32, or Cotati’s SB 9 rules. The description of housing types is a general observation. For countywide context, see our Sonoma County multifamily guide and Sonoma County commercial guide.

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

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