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

What multifamily in Forestville looks like

Income property in Forestville is mostly small: duplexes and a few small apartment buildings near the Highway 116 core, houses with an ADU or cottage, older river-area cabins rented long term, mobile homes, and the occasional mixed-use building with an apartment over a shop. Large apartment complexes are rare, largely because sewer service stops at the edge of the Forestville Water District. For two to four units, read financing 2-4 unit properties; for anything larger, see apartment building loans.

Where the zoning allows it

Forestville is unincorporated, so the County’s residential Article 08 governs. Look up each parcel in the Official Zoning Database.

The zoning map number sets density only up to the General Plan maximum, whichever is lower. Multifamily projects of four or more units have their own standards in Section 26-08-050, which also bars vacation rentals, timeshares and transient stays in them.

SB 9. Permit Sonoma’s streamlined housing page limits SB 9 to single-family zones within a U.S. Census urban area. The County’s census urban area layer includes a Forestville urban cluster, so some R1 lots in town may qualify, subject to the County’s site checklist and an owner-occupancy affidavit for lot splits. Outer rural parcels likely will not. See our SB 9 lot split guide and ADU investment guide.

Rent rules: state rent cap plus County tenant protections

Rent cap. The Attorney General’s rent cap page, updated July 16, 2026, does not name Sonoma County in its regional table, so the "All Other Counties" figure of 8.6% applies to covered units for increases from August 1, 2026 through July 31, 2027. No Sonoma County city or area appears on its local rent control chart, and the County has no local rent cap for Forestville.

Ordinance 6496. The County’s Residential Tenancy Protections Ordinance, finally passed September 17, 2024, covers rental units in unincorporated areas like Forestville and builds on Civil Code 1946.2:

• Just cause from the start. Protection begins when lawful occupancy begins, not after the state’s waiting period.
• Nonpayment. Unpaid rent is a just cause only if more than one month’s rent is owed.
• Relocation. For no-fault terminations, the payment is the greater of HUD Fair Market Rent for the Santa Rosa area or the actual monthly rent.
• Filing. Per the County’s landlord page, termination information goes to the County within three days of the notice, with required materials in English and Spanish.
• Affordable units. Certain deed-restricted affordable units that state law would exempt are covered.

See our AB 1482 guide and just cause eviction guide.

Forestville rental property rules

• Short-term rentals. Permit Sonoma does not allow vacation rentals in R1, R2, R3, ADUs or farmworker housing. Three Forestville neighborhoods, Hacienda, Rio Dell and Summerhome Park, carry 5% cap zones according to the District 5 fact sheet. Buying a duplex to run as nightly rentals is not a plan that works here. More in our vacation rental rules.
• Transfer tax. Only the County’s documentary transfer tax of $0.55 per $500 applies.

Sewer, septic and flood

• Sewer. The Forestville Water District serves about 3,000 customers in central Forestville and Mirabel Heights with water, sewer and recycled water. Outside it, septic capacity usually sets how many units a lot can hold; see our page on Forestville water and wastewater.
• Regional wastewater. A Sonoma Water feasibility study has looked at combining Forestville’s plant with Guerneville, Graton and Occidental; any project is still in planning.
• Flood. In mapped floodplain, County Chapter 7B requires a new or substantially improved home’s lowest floor at least 12 inches above base flood elevation. For homes, the trigger is improvement costing 40% of market value, counted across permits over three years.
• Older buildings. Budget SB 721 balcony inspections for three or more units with elevated decks, and consider a seismic retrofit review for older wood-frame buildings on hillsides or over parking.

Underwriting a Forestville multifamily purchase

1. Confirm R2, R3 or legal nonconforming status for every unit, and permits for any converted cottage.
2. Confirm the parcel is in the Forestville Water District, or get septic records and a capacity check.
3. Classify each unit under AB 1482 and Ordinance 6496, and model increases at or below 8.6% for covered units.
4. Budget relocation at Fair Market Rent or actual rent for any planned no-fault move-out.
5. Collect leases, the rent roll and estoppel certificates.
6. Rebuild expenses with reassessed taxes, flood insurance where mapped and SB 721 costs in our rental property analysis.

Questions people ask

Sources & notes

1. County Code Article 08, Residential Zones
2. Article 10, Commercial Zones
3. Permit Sonoma, streamlined housing (SB 9) and County census urban areas layer
4. Ordinance 6496 and County landlord information
5. California Attorney General, rent caps
6. Permit Sonoma, vacation rentals and District 5 fact sheet
7. Forestville Water District
8. Sonoma Water regionalization flyer
9. County Code Chapter 7B
10. Sonoma County Recorder, documentary transfer tax

Note: The census urban area layer is a 2010-vintage County dataset; the County’s SB 9 screening map controls. We did not verify which parcels carry R2 or R3, mobile home park rent rules, or the housing types present, which are general observations. See also our Sonoma County multifamily guide and Sonoma County commercial guide.

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

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