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

What multifamily in Kelseyville looks like

Kelseyville’s rental housing is small-town and farm-related: duplexes and small apartment buildings near Main Street, government-assisted complexes, mobile home parks and farmworker housing in Big Valley. The Kelseyville Area Plan counted six mobile home parks plus assisted and private multifamily housing. It called the supply of affordable housing sufficient and named overcrowded farm labor quarters and needed rehabilitation as the main housing problems. For financing, see financing 2-4 unit properties and apartment building loans.

Where the zoning allows it

Kelseyville is unincorporated and follows the Lake County zoning ordinance:

Two Kelseyville-specific limits. The area plan requires an acoustical study for new multifamily housing inside the 55 dBA noise contour along Highway 29. Residential density near Lampson Field must follow the Airport Land Use Compatibility Plan. Both can cut the unit count on otherwise eligible land.

Farmworker housing. In rural Big Valley, agricultural employee housing follows state law and the county’s agricultural district rules. Confirm the permit path with the county before buying a ranch with labor housing.

ADUs and SB 9. Article 27 allows one granny unit or second unit per lot. Granny units can be 720 square feet on lots under 40,000 square feet and 1,008 on larger lots. Ask the county how state ADU law changes those numbers. See our ADU investment guide. SB 9 applies to unincorporated land only in qualifying urban areas, and not on farm-zoned parcels. See our SB 9 guide.

Rent rules: state law only

The Attorney General’s rent cap page lists no local rent control in Lake County. The "All Other Counties" row sets 7.7% from August 1, 2025, and 8.6% from August 1, 2026 through July 31, 2027. State just cause rules apply to covered units. See our AB 1482 guide and just cause eviction guide.

Kelseyville rental property rules

• Mobile home parks. Under Article 43, new parks need a major use permit, 5 acres and no more than 10 spaces per acre. Closures require a relocation plan and conversion impact report. Several of Kelseyville’s parks likely predate current standards, so underwrite them as legal nonconforming.
• Condo conversions need a major use permit under Article 44.
• Short-term rentals. The county is drafting rules for unincorporated areas. Stays of 30 days or less owe the 9% TOT.
• No county rental registry appears in the code we reviewed.
• Home businesses and B&Bs. On R2 lots, home occupations are limited to residents, eight customers a day and ten deliveries a week. A bed and breakfast with up to two guest rooms needs a zoning permit valid for five years, with one parking space per guest room.
• Resident open space. R3 projects need 100 square feet of private open space or balcony per unit. Projects of more than seven units also need 300 square feet per unit of usable recreation area, and yards and parking don’t count toward it.

Sewer, water, fire and site constraints

• Sewer and water. The area plan identifies Kelseyville County Waterworks District No. 3 for water (about 854 connections) and sewer (about 1,050 connections in town), with plant capacity of 260,000 gallons per day. Those figures date from the plan’s preparation, so ask the district for current capacity and fees before adding units. Finley water comes from CSA 6. Outlying areas use septic, which means 40,000-square-foot minimum lots for any multifamily district.
• Groundwater. Big Valley relies mainly on groundwater. The plan discourages running water and sewer lines into agricultural areas.
• Septic density. The plan calls for water quality monitoring where septic density exceeds one unit per acre.
• Fire. The Kelseyville Fire Protection District’s headquarters is at 4020 Main Street. Lake LAFCo’s 2025 review places the district in high and very high fire hazard zones and found its water system inadequate for fire protection. Expect fire-flow conditions on new multifamily projects.
• Older buildings. Older wood-frame buildings may warrant a seismic retrofit review. Buildings of three or more units with elevated decks need SB 721 inspections.

Underwriting a Kelseyville multifamily purchase

1. Confirm the district and the parcel’s KCWD No. 3 or septic status, then test the unit count against the lot minimums.
2. Check the Highway 29 noise contour and the Lampson Field compatibility zones for any development upside.
3. Classify units under AB 1482 and model increases at or below 8.6%.
4. For mobile home parks or farm labor housing, confirm permits and nonconforming status.
5. Collect leases and statements, and get estoppel certificates.
6. Rebuild expenses with reassessed taxes and district charges in our rental property analysis.

Questions people ask

Sources & notes

1. Kelseyville Area Plan
2. Lake County Zoning Ordinance: Art. 11 R2, Art. 12 R3, Art. 19 C2, Art. 27, Art. 43, Art. 44
3. Lake LAFCo Fire Protection Districts MSR (2025)
4. California Attorney General, Rent Caps
5. Lake County STR committee news and TOT Ordinance

Note: The area plan’s connection counts are dated. Farmworker housing permits and SB 9 eligibility were not verified.

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

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