Buying a Home in Contra Costa County, CA: Transfer Tax, Fault Zones & Mello-Roos

Richmond has a steeply tiered transfer tax, East County new construction often carries Mello-Roos, and the Hayward and Concord faults run through much of the county's populated core.

Contra Costa County spans very different real-estate environments — dense, older cities in the west (Richmond, El Cerrito, San Pablo) near the Bay, established suburbs in the center (Walnut Creek, Concord, Lafayette, Danville), and fast-growing newer development in the east (Brentwood, Oakley, Antioch). Transfer tax, earthquake fault zoning, and Mello-Roos exposure all differ meaningfully by exactly where in the county a property sits.

What’s the transfer tax in Contra Costa County?

The county base is the state rate of $1.10 per $1,000 of sale price, but Richmond adds a steeply tiered city tax and El Cerrito adds a flat $12.00 per $1,000 on top of that base.

Most other Contra Costa cities (Concord, Walnut Creek, Antioch, Pittsburg, Danville, San Ramon, Lafayette, Orinda, Moraga, Pleasant Hill, Martinez, Hercules, Pinole, San Pablo, Clayton, Brentwood, Oakley) have not been confirmed to have their own added transfer tax — the county's $1.10/$1,000 base is likely the only tax that applies, but verify directly with the city's finance department or the county Clerk-Recorder before relying on that, since new city ballot measures are common statewide. Transfer tax is customarily a seller-side cost by convention, but it's negotiable in the contract.

How much higher is transfer tax in Richmond?

Richmond's Measure H tiers the city transfer tax from 0.7% below $1M up to 3% at $10M and above, layered on top of the county's $1.10/$1,000 base — a real, material cost concentrated at specific price bands, similar in spirit to LA's Measure ULA.

The tiers: under $1,000,000 stays at the original 0.7% ($7.00/$1,000); $1,000,000–$2,999,999 rises to 1.25% ($12.50/$1,000); $3,000,000–$9,999,999 jumps to 2.5% ($25.00/$1,000); $10,000,000+ reaches 3% ($30.00/$1,000). A $900,000 Richmond sale works out to roughly $8.10 per $1,000 combined (county + city), about $7,290, before any negotiated buyer/seller allocation. Factor Richmond's tier into negotiations the same way you would LA's mansion tax on any higher-priced property.

Are there earthquake fault zones to check in Contra Costa County?

Yes — the Hayward Fault runs through the western and central county, with CGS-mapped Alquist-Priolo zones touching Concord, Danville, El Cerrito, Hercules, Lafayette, Martinez, Pinole, Pleasant Hill, Richmond, San Pablo, San Ramon, Walnut Creek, and parts of Clayton and Pittsburg; the separate Concord Fault runs through the central county near Concord and Mount Diablo.

If a property sits within a mapped Earthquake Fault Zone, the seller must disclose this on the Natural Hazard Disclosure Statement (Civil Code §1103 et seq.), and construction/improvement restrictions apply near the fault trace itself, not the whole zone. Use the state's EQ Zapp tool to check a specific parcel — city-level generalizations aren't precise enough to rely on for an actual purchase decision.

Is Mello-Roos common in East County (Brentwood, Oakley, Antioch)?

Yes — newer development in Brentwood, Oakley, and parts of Antioch has meaningfully higher Mello-Roos CFD prevalence than the rest of the county, typically running roughly $1,200–$3,500/year on top of standard property tax.

Brentwood has multiple Community Facilities Districts funding parks, roads, and schools tied to subdivisions built since the early 2000s. Antioch has a large southeast-city CFD covering roughly 11,760 homes that funded five elementary schools, two middle schools, a high school, and a community park, with the annual special tax based on house square footage. Oakley also has Mello-Roos in some newer developments. California Civil Code §1102.6b requires the seller to provide a Notice of Special Tax disclosing the current amount and the district's expiration date (often 20–30+ years from formation) — ask for it specifically if it isn't included, and cross-check the county assessor's parcel record directly, since disclosure omissions happen. Two similarly-priced East County homes can have very different true monthly costs once Mello-Roos is factored in.

Is there rent control in Contra Costa County?

It varies significantly by city — Richmond, Concord, and Antioch all have local rent-stabilization ordinances beyond the statewide AB 1482 baseline, while Walnut Creek and most other cities rely on AB 1482 alone.

Richmond's Fair Rent, Just Cause for Eviction, and Homeowner Protection Ordinance (Measure L, in effect since January 2017) caps annual increases on covered units at 100% of local CPI and requires just cause for eviction, covering buildings with 2+ units that received a certificate of occupancy before February 1, 1995. Concord's Rent Stabilization and Just Cause ordinance (effective April 2024, amended May 2025) caps pre-February-1995 multifamily units at a maximum 5% annual increase as of August 2025, and extends just-cause protection to owners of 3+ single-family homes/condos. Antioch's Rent Stabilization Ordinance (since November 2022) covers pre-February-1995 units at an unusually tight roughly 0.78%/year cap as of the most recent adjustment (single-family homes and condos exempt). If you're buying a property with tenants in place, the existing lease and any applicable local just-cause protections generally survive the sale — confirm the certificate-of-occupancy date and current tenancy status before assuming you can occupy immediately after close.

Disclosure landscape

Earthquake Fault Zone disclosure is required on the Natural Hazard Disclosure Statement for properties within a mapped Hayward or Concord fault zone — check the specific parcel via EQ Zapp, not the city generally.
Notice of Special Tax disclosure (Civil Code §1102.6b) is required for any active Mello-Roos CFD, common in Brentwood, Oakley, and parts of Antioch — cross-check against the county assessor record.
Rent-control and just-cause coverage in Richmond, Concord, and Antioch depends on the building's certificate-of-occupancy date — verify directly with the applicable city rent program rather than assuming.

Frequently asked

Does Contra Costa County have a mansion tax like LA City's Measure ULA?

Not countywide, but Richmond comes closest — its Measure H tiers the city transfer tax up to 3% on sales of $10M and above, a real cost concentrated at higher price bands. Most other Contra Costa cities have no confirmed added transfer tax beyond the state base.

How do I find out if a specific Brentwood or Antioch property has Mello-Roos?

Ask for the seller's Notice of Special Tax disclosure (required under Civil Code §1102.6b) and independently check the county assessor's parcel record — disclosure omissions do happen, and CFD amounts don't show up in a basic property tax estimate.

If I buy a tenant-occupied duplex in Richmond, can I raise the rent right away?

Not necessarily. If the building received its certificate of occupancy before February 1, 1995, it's likely covered by Richmond's Fair Rent ordinance, which caps annual increases at 100% of local CPI and requires just cause for eviction — verify coverage with the Richmond Rent Board before assuming.

This is educational guidance, not legal advice. Consult a California real estate attorney for legal questions specific to your transaction.