Multifamily and Duplex Properties for Sale in Rohnert Park: Zoning and Rent Rules

What multifamily in Rohnert Park looks like

Rohnert Park was built largely as a planned city, so its income property is organized by zone: duplexes and townhomes in medium-density sections, apartment complexes in high-density zones, newer housing in the University District and Southeast specific plan areas, apartments within mixed-use and downtown districts, and five mobile home parks covered by a long-standing space rent ordinance. Sonoma State University nearby shapes demand for student-oriented rentals. For two to four units, read financing 2-4 unit properties; for larger buildings, see apartment building loans.

Where the zoning allows it

Article I of Chapter 17.06 controls residential uses. It sets intensity by lot size and floor area ratio rather than units per acre.

District	Duplex	Multifamily	Lot size or FAR	Mobile home park
R-R Rural Residential	Not listed	Not listed	Lots typically 40,000 sq ft or more	Not listed
R-E Estate Residential	Not listed	Not listed	Lots typically 17,000 sq ft or more	Not listed
R-L Low Density	Permitted through the SB 9 process	Not listed	FAR 0.40	Not listed
R-M Medium Density	Permitted	Not permitted	3,700 sq ft minimum lot in a planned development; FAR 0.55	Conditional
R-H High Density	Permitted	Permitted	FAR 1.15	Conditional
DTR-H Downtown High Density	Not listed	Permitted	R-H standards unless stated	Conditional
M-U Mixed Use	—	Permitted	FAR 2.0 with housing	—
DTM-U Downtown Mixed Use	—	Conditional, only within a mixed-use project	FAR 2.0 with housing	—

Reading the table. R-M allows duplexes but not apartment buildings, so a "fourplex" in an R-M section should be checked for a planned development approval or nonconforming status. R-H and downtown DTR-H are the apartment zones. Supportive housing is permitted in R-M, R-H and DTR-H. Specific plan areas such as the University District, planned for about 1,665 homes, and the Southeast plan, which allows up to 499, follow their own plan standards.

ADUs and SB 9. ADUs are permitted in all residential districts under Section 17.08.040, and R-L duplexes are permitted through the SB 9 process. See our SB 9 lot split guide and ADU investment guide.

Growth management. Title 17 includes a Growth Management Program in Chapter 17.19, which can affect the pace of new residential approvals; ask Planning how it applies to a project.

Rent rules: state law for apartments

State rent cap. The Attorney General’s rent cap page, updated July 16, 2026, puts Sonoma County in the "All Other Counties" group, with a maximum increase of 8.6% for covered units from August 1, 2026 through July 31, 2027. It lists no Sonoma County city with local rent stabilization.

Just cause. We found no Rohnert Park apartment rent or just cause ordinance on the city pages we reviewed, so plan on state law: AB 1482 just cause after 12 months of occupancy and one month’s rent in relocation for no-fault terminations of covered tenancies. Confirm with the city before closing. Note that the county’s tenant ordinance covers only unincorporated land, not Rohnert Park.

See our AB 1482 guide and just cause eviction guide.

Rohnert Park rental property rules

Mobile home space rent. The Mobile Home Rent Appeals Board FAQ says the city’s mobile home ordinance was approved by residents in 1987 and cites Ordinance No. 949. Rent control covers residents of the five parks who are not on leases.
How increases work. Space rent may rise for the next budget year when CPI rises, stays flat if CPI falls, and is capped at 4.0%. A five-member board appointed by the City Council sets the maximum increases each October, reviews pass-through expenses and hears petitions.
Park conversions. Converting a mobile home park to another use falls under Chapter 17.23, and a Mobile Home Park Overlay District is in Article IX of Chapter 17.06.
Transfer tax. The County Recorder charges $0.55 per $500, less assumed loans, and lists no separate Rohnert Park city rate.

Building and inspection issues

Much of Rohnert Park’s apartment stock is wood-frame construction from the city’s main growth decades. Buildings with open ground-floor parking should be screened for seismic retrofit needs, and complexes of three or more units with elevated balconies, stairs or walkways need SB 721 balcony inspections. For a mixed-use building downtown, confirm whether the ground floor must stay commercial under DTM-U.

Underwriting a Rohnert Park multifamily purchase

Match the unit count to the zone: apartments in R-M need an explanation.
Classify each unit under AB 1482, including the 15-year new construction exemption, and model covered increases at or below 8.6%.
For student-oriented rentals near the university, review lease terms and turnover in the rent roll.
For a mobile home park, separate lease and non-lease spaces and model the 4.0% cap on non-lease spaces.
Collect leases, the rent roll and estoppel certificates.
Rebuild expenses with reassessed taxes and SB 721 costs in our rental property analysis.

Questions people ask

Is there rent control in Rohnert Park?

Not for apartments, based on the state’s list and the city pages we reviewed. AB 1482 applies to covered units, and mobile home spaces have a local ordinance.

How much can mobile home space rent go up in Rohnert Park?

It follows CPI, does not rise if CPI falls, and is capped at 4.0% a year for residents not on leases.

Which zones allow apartment buildings?

R-H, DTR-H and the M-U district permit multifamily; Downtown Mixed Use allows it conditionally as part of a mixed-use project.

Can I build a duplex in an R-L neighborhood?

R-L permits duplexes through the SB 9 process, subject to state eligibility rules.

Does the county’s tenant ordinance apply in Rohnert Park?

No. Sonoma County’s tenant protection ordinance covers unincorporated areas only.

Does Rohnert Park add a transfer tax?

No separate city rate is listed; the county’s $0.55 per $500 applies.

Sources & notes

Note: We did not read the mobile home ordinance text (Chapter 9.70), the ADU section, Chapter 17.19 or the specific plan documents. The absence of a city apartment ordinance is based on the state list and the pages reviewed, not a full code search. Comments on the age of the housing stock and student demand are general observations.

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

Inquire about a listing or to schedule a meeting

Matthew Martinez

Your inquiry is processed through our iHomefinder service. Review the form’s contact choices before submitting. Privacy Policy · Terms of Use.