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

What multifamily in Belvedere looks like

Belvedere is overwhelmingly single-family, so multifamily property is scarce. What exists is a small set of duplexes and apartment buildings in the R-2 and R-3 zones, many near the lagoon and along Beach Road, a few condominiums, and mixed-use potential in the MU zone near downtown. ADUs and SB 9 duplexes on single-family lots are the main source of new rental units. Many buildings sit at the water’s edge, so flood elevation shapes what can be built. For financing, see financing 2-4 unit properties and apartment building loans.

Where the zoning allows it

Belvedere’s ten zones are listed in § 19.12.010. These allow two or more units:

R-3 affordable incentive. When 20% of new units are affordable to households under 80% of area median income, on consolidated sites of at least half an acre, § 19.36.040(A) raises density to 20–28 units per acre. It cuts parking to one space plus half a common space per unit and raises height to 38 feet on Beach Road. Hotels, boarding houses and roof decks are prohibited in R-3.

SB 9. Chapter 19.77 allows two units on single-family lots in R-1C, R-1L, R-1W and R-15 through ministerial review by the Planning Director. One unit must be the owner’s principal residence. A recorded covenant bars rentals under 30 days. Sites in high fire hazard zones, FEMA flood zones, historic districts or high prehistoric-sensitivity areas are excluded unless an exception in the chapter applies. On a lot created by an urban lot split, no ADUs are allowed. See our SB 9 lot split guide. ADUs and JADUs follow Chapter 19.79. See our ADU investment guide.

Rent rules: state law only

The Attorney General’s rent cap page puts Marin County in the San Francisco Area region. The maximum increase for covered units is 6.3% for increases from August 1, 2025, and 8.8% from August 1, 2026 through July 31, 2027. No Marin city is listed with a local cap, and the Belvedere code index we reviewed has no rent or eviction chapter. State just cause and relocation rules govern covered tenancies. See our AB 1482 guide and just cause eviction guide.

Marin County’s mandatory mediation program for increases over 5% covers only unincorporated Marin and San Rafael. In Belvedere, mediation is voluntary.

Belvedere rental property rules

• Inclusionary housing in MU. Chapter 19.95 requires 15% affordable units in MU projects of 7 to 12 units and 20% above 12. At least 5% must be very low or low income, recorded before building permits.
• Senior housing guarantees. SC-H projects must keep at least 51% of units affordable at or below 80% of county median income and record a use restriction before occupancy.
• Condominium conversions. Chapter 19.38 regulates condominiums and community apartments. Review it before planning a conversion exit.
• Transfer tax. Belvedere’s Chapter 3.20 sets $0.275 per $500. The county Recorder’s sheet lists $0.55 per $500 and names only San Rafael as adding a city tax, so confirm the charge with escrow.

Flood elevation, sewer laterals and waterfront buildings

R-3 height is measured from base flood elevation plus one foot of freeboard, which tells you how flood-driven Belvedere’s waterfront multifamily is. Get flood zone, elevation certificate and insurance quotes early. Sanitary District No. 5 requires a CCTV lateral inspection under Ordinance 2014-02a when a property is bought or sold, after more than $50,000 of work in three years, or when nearby sewer or paving work occurs. Laterals replaced within 20 years, or inspected and repaired within three years, are exempt. Older wood-frame buildings over the water or on fill may warrant a seismic retrofit review. Buildings with three or more units and elevated balconies or decks need SB 721 inspections, which matters for water-view decks.

Underwriting a Belvedere multifamily purchase

1. Confirm the zone on the December 2025 map and test the unit count against 5–20 units per net acre and the 6,000-square-foot minimum lot.
2. Check flood zone and elevation, since they control R-3 height and insurance cost.
3. Classify each unit under AB 1482 and model increases at or below 8.8%.
4. Order the Sanitary District No. 5 lateral inspection and price any repair.
5. Collect leases, the rent roll and estoppel certificates, and review any recorded affordability or SB 9 covenants.
6. Rebuild expenses with reassessed taxes, flood insurance and deck inspections in our rental property analysis.

Questions people ask

Sources & notes

1. Belvedere Municipal Code (GoCodebook, Sept. 2026 ed.): Ch. 19.12, Ch. 19.28, Ch. 19.36, Ch. 19.37, Ch. 19.41, Ch. 19.77, Ch. 19.95, Ch. 3.20
2. California Attorney General, Rent Caps
3. Marin County, Mandatory Mediation Program
4. Sanitary District No. 5, lateral inspections
5. Marin County Recorder, transfer tax

Note: We did not review Chapters 19.38 or 19.79 in full. No short-term rental chapter appeared in the code index we reviewed, so ask the city how stays under 30 days are treated.

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

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