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

What multifamily in Graton looks like

Graton is a small community, so income property is modest: houses with an ADU or junior unit, a few duplexes and small rental groupings near the town center, apartments over storefronts, rural parcels with a second unit or farmworker housing, and some mobile homes. Whether a lot can take another unit usually comes down to sewer hookups from the Graton Community Services District, or septic capacity outside it. For two to four units, read financing 2-4 unit properties; for larger buildings, see apartment building loans.

Where the zoning allows it

Graton is unincorporated, so County Article 08 controls residential uses. Check each parcel in the Official Zoning Database.

Density is capped at the lower of the General Plan and the zoning map. Four or more units must meet the multifamily standards in Section 26-08-050.

Urban service area. The County maps a Graton urban service area of about 278 acres. Higher-density residential zoning, where it exists, is typically inside it.

SB 9. Permit Sonoma’s SB 9 page requires a single-family zone inside a U.S. Census urban area. A point query of the County’s census urban area layer at central Graton returns the 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. Sewer hookups, not zoning, may then be the real limit. Rural lots outside the cluster will not qualify. See our ADU investment guide and SB 9 lot split guide.

Rent rules: state rent cap plus County tenant protections

State cap. The Attorney General treats Sonoma County as one of the "All Other Counties." On the page updated July 16, 2026, covered units may go up 8.6% for increases from August 1, 2026 through July 31, 2027. Graton has no local rent control.

County ordinance. The County’s Ordinance 6496, finally passed September 17, 2024, applies across unincorporated Sonoma County, Graton included:

• No waiting period. A tenant has just cause protection from the start of lawful occupancy.
• Nonpayment threshold. Nonpayment must exceed one month’s rent to be a just cause.
• Relocation. No-fault relocation is the larger of HUD Fair Market Rent for the Santa Rosa area or the actual rent.
• Reporting. Landlords report terminations to the County within three days, using the forms on the landlord page, and give tenants materials in English and Spanish.

See our AB 1482 guide and just cause eviction guide.

Graton rental property rules

• Short stays. Vacation rentals are barred in R1, R2, R3, ADUs and farmworker housing. A hosted room rental, with the owner living there, is permitted in R1. The County’s 2023 cap and exclusion staff report did not propose a Graton zone. More in our vacation rental rules.
• Transfer tax. The County rate of $0.55 per $500 is the only transfer tax.

Sewer, septic and flood

• Sewer hookups. The Graton Community Services District requires residences in its area to connect. It offers new hookups only in limited numbers, charges a connection fee, and bills annual service charges on the property tax bill. A new unit may need a new hookup, so ask the district before counting on added units.
• Plant limits. The district’s 2018 water board permit describes a 0.14-million-gallon-per-day tertiary plant with seasonal discharge to Atascadero Creek and transfers to the Forestville Water District plant.
• Future changes. Sonoma Water’s regionalization study of Graton and nearby plants could change capacity and costs, but no project is approved. See our Graton water and wastewater page.
• Flood. In floodplain, Chapter 7B requires homes to sit 12 inches above base flood elevation once improvements reach 40% of value over three years. Laguna AE parcels also face the zero-net-fill rule in Section 26-58-030(d).
• Inspections. Three-plus-unit buildings with elevated decks need SB 721 inspections. Older wood-frame buildings may warrant a seismic retrofit review.

Underwriting a Graton multifamily purchase

1. Confirm the zone and legal unit count, including any older second units.
2. Get the Graton CSD’s record of connections for the parcel, or septic records if outside it.
3. Classify units under AB 1482 and Ordinance 6496, and model covered increases at or below 8.6%.
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, sewer charges and flood insurance in our rental property analysis.

Questions people ask

Sources & notes

1. County Code Article 08, Article 10 and Chapter 7B
2. Ordinance 6496 and landlord page
3. California Attorney General, rent caps
4. Graton Community Services District and 2018 water board order
5. County urban service areas and census urban areas (GIS)
6. Permit Sonoma SB 9 page and vacation rentals
7. Sonoma Water regionalization flyer
8. Sonoma County Recorder, documentary transfer tax

Note: The housing stock description is general. We did not confirm which Graton parcels are zoned R2 or R3, the current fee schedule, renewal of the 2018 water board order, or mobile home park rules. The census layer is a 2010-vintage County dataset. 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: Graton real estate guide · Commercial real estate in Graton · Multifamily investing guide · Investor services