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Contra Costa County, CA Real Estate & Homes for Sale

By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.

Contra Costa County is the East Bay county of 1,170,070 people (U.S. Census Bureau, July 2025 estimate) that reaches from Richmond and the San Pablo Bay shore east over the hills to Walnut Creek and Concord, and on to Antioch, Brentwood and the Delta. Its median price for an existing single-family home was $870,000 in September 2026, essentially flat from $869,000 a year earlier, according to the California Association of REALTORS® (C.A.R.). Only Richmond and El Cerrito add a city transfer tax to the county’s, El Cerrito and Kensington sellers need a sewer lateral certificate, and Richmond, Antioch and Concord have their own rent rules.

The county seat is Martinez. Its five broad areas, the west county, the central county, Lamorinda, the San Ramon Valley and the east county with the Delta, differ in housing, travel and rules more than many counties differ from each other. This guide compares every town and community we cover, then works through the taxes, certificates, rent rules, hazards, utilities and transit a buyer or seller meets. MLS area labels can combine communities, so confirm any rule against the parcel record.

Contra Costa County homes for sale

Contra Costa County market report

Contra Costa County by the numbers

Measure	Figure	Period and source
Population	1,170,070	July 1, 2025 estimate, Census
Population at the 2020 Census	1,165,927	April 1, 2020, Census
Land area	716.93 square miles	2020, Census
Housing units	436,791	July 1, 2025 estimate, Census
Owner-occupied share of homes	68.0%	2020–2024, Census ACS
Median value, owner-occupied homes	$866,800	2020–2024, Census ACS
Median owner costs with a mortgage; median gross rent	$3,435; $2,375 a month	2020–2024, Census ACS
Mean travel time to work	35.3 minutes	2020–2024, Census ACS
Median price, existing single-family homes	$870,000 ($869,000 a year earlier)	September 2026, C.A.R.
Change in sales from a year earlier	Down 5.7%	September 2026, C.A.R.

The population grew about 0.4% from the 2020 count to the July 2025 estimate, by our arithmetic, while Alameda County’s fell. Contra Costa’s owner-occupied share, 68.0%, is well above Alameda County’s 54.4%, and its mean commute, 35.3 minutes, is longer. The Census figures are five-year survey averages; the C.A.R. median is one month of sales.

How Contra Costa compares

Area	C.A.R. median, September 2026	Change from a year earlier
Contra Costa County	$870,000	+0.1%
Alameda County	$1,265,000	+1.2%
Solano County	$580,000	−4.6%
Marin County	$1,678,750	+1.7%
SF Bay Area region	$1,325,000	+1.9%
California	$899,720	+1.7%

Contra Costa’s median was about 66% of the regional figure, $395,000 below Alameda County’s and $290,000 above Solano’s. Inside the county the spread is wide, from Rossmoor co-ops to Lamorinda and San Ramon Valley estates, so a countywide number is only a starting point for pricing a specific home.

Contra Costa County towns and areas compared

Every Contra Costa town and community guide on our site is in this table, grouped by area. The regions are our editorial grouping, not official districts.

Town or area	Government	Region	Setting and what to check
Richmond	City	West County	Bay shoreline city with BART, Capitol Corridor and a ferry; city transfer tax and rent ordinance
Point Richmond	City of Richmond	West County	Older neighborhood at Richmond’s west end near the bay; Richmond tax and rent rules apply
Hilltop	City of Richmond	West County	Richmond area along I-80 around the Hilltop shopping district; condos and newer tracts
El Cerrito	City	West County	Two BART stations; $12.00 city transfer tax; sewer lateral certificate through the Stege area
Kensington	Unincorporated	West County	Hill community above Berkeley and El Cerrito; sewer lateral certificate through the Stege area
San Pablo	City	West County	Small city bordered by Richmond
El Sobrante	Unincorporated, with some Richmond addresses	West County	Valley and hillside homes along San Pablo Dam Road; confirm which side of the city line
Pinole	City	West County	San Pablo Bay city along I-80
Hercules	City	West County	Bay-side city north of Pinole with planned neighborhoods
Rodeo	Unincorporated	West County	Small bay-side town north of Hercules
Crockett	Unincorporated	West County	Hillside town on the Carquinez Strait at the north edge of EBMUD’s water area
Port Costa	Unincorporated	West County	Tiny historic village on the Carquinez Strait east of Crockett
Martinez	City; county seat	Central County	Waterfront downtown on the strait; Amtrak station and North Concord/Martinez BART
Pacheco	Unincorporated	Central County	Small area between Martinez, Pleasant Hill and Concord
Concord	City	Central County	Large central city with Concord and North Concord/Martinez BART; city rent rules
Clayton	City	Central County	Small city at the foot of Mount Diablo east of Concord
Pleasant Hill	City	Central County	Mostly single-family neighborhoods; Pleasant Hill/Contra Costa Centre BART on its edge
Walnut Creek	City	Central County	Downtown condos, hillside homes and a BART station
Rossmoor	Walnut Creek address	Central County	Age-restricted 55+ community of co-ops, condos and a few single-family homes
Lafayette	City	Lamorinda	Hillside lots and a downtown along Mount Diablo Boulevard; BART station
Orinda	City	Lamorinda	Wooded hillside lots; BART station; EBMUD water area
Moraga	Town	Lamorinda	Valley and hillside neighborhoods with no BART station of its own
Rheem Valley	Town of Moraga	Lamorinda	Moraga neighborhood around the Rheem Valley shopping center
Canyon	Unincorporated	Lamorinda	Small redwood-canyon community between Moraga and Oakland; check access, water and septic
Alamo	Unincorporated	San Ramon Valley	Larger lots between Walnut Creek and Danville along I-680
Danville	Town	San Ramon Valley	I-680 town with a historic downtown and hillside neighborhoods
Diablo	Unincorporated	San Ramon Valley	Small community at the base of Mount Diablo east of Danville
Blackhawk	Unincorporated	San Ramon Valley	Planned community east of Danville; read association documents closely
San Ramon	City	San Ramon Valley	Planned neighborhoods at the Alameda County line; nearest BART is in Dublin
Pittsburg	City	East County	Waterfront city with Pittsburg/Bay Point and Pittsburg Center BART
Bay Point	Unincorporated	East County	Community west of Pittsburg beside the Pittsburg/Bay Point BART station
Antioch	City	East County	Large east-county city at the end of the BART line; city rent rules
Oakley	City	East County	Newer subdivisions between Antioch and the Delta
Brentwood	City	East County	Newer subdivisions beside orchards and farmland
Knightsen	Unincorporated	East County	Farm parcels between Oakley and Brentwood; wells and septic are common questions
Bethel Island	Unincorporated	East County	Delta island behind levees; docks, flood zone and levee questions
Discovery Bay	Unincorporated	East County	Delta waterfront community with homes on channels; dock and flood questions
Byron	Unincorporated	East County	Rural southeast corner of the county; farm and ranch parcels
Unincorporated Contra Costa County	County	All areas	From Kensington to Byron; county planning and building, no city transfer tax

Unincorporated communities such as Alamo, Blackhawk, Kensington and Byron are governed by the county, not a city, so planning, building and many service questions go to county departments or special districts. A mailing name is not a city boundary; our property responsibility ledger helps keep each record straight.

West County

Richmond, El Cerrito, San Pablo, Pinole and Hercules line the bay and I-80, with Kensington, El Sobrante, Rodeo, Crockett and Port Costa unincorporated. This is the part of the county where city transfer tax, the sewer lateral certificate and a city rent ordinance can all apply.

Central County and Lamorinda

Martinez, Concord, Pleasant Hill, Clayton and Walnut Creek form the central county along I-680 and State Route 4. Lafayette, Orinda and Moraga, west of Walnut Creek through the hills, are hillside markets where the individual lot, slope and access drive value more than any area average.

San Ramon Valley

Alamo, Danville, Diablo, Blackhawk and San Ramon run south along I-680 to the Alameda County line. There is no BART station in the valley; the nearest are Walnut Creek and Dublin/Pleasanton.

East County and the Delta

Pittsburg, Antioch, Oakley and Brentwood hold most of the county’s newer subdivisions, while Knightsen, Byron, Bethel Island and Discovery Bay add farmland and Delta waterfront. A waterfront home, a hillside house and a planned-community lot each need different questions; see our Contra Costa land and agricultural property guide for rural parcels.

Transfer tax by city

The county tax is $0.55 for each $500 of value, which is $1.10 per $1,000, under Revenue and Taxation Code section 11911; it excludes any loan that stays on the property. Two cities add their own tax, both listed by Ticor Title’s 2026 guide and Old Republic Title’s Bay Area sheet:

Where	City rate	On $870,000 (county median)	On $1,500,000
Richmond	0.7% under $1,000,000; 1.25% from $1,000,000 to $2,999,999; 2.5% from $3,000,000 to $9,999,999; 3% at $10,000,000 and above	$6,090 city; $7,047 with county tax	$18,750 city; $20,400 with county tax
El Cerrito	$12.00 per $1,000	$10,440 city; $11,397 with county tax	$18,000 city; $19,650 with county tax
Every other city and unincorporated area	No city tax	$957	$1,650

Richmond’s rate applies to the whole price once a sale crosses a threshold, so a sale just over $1,000,000 owes noticeably more than one just under it; plan pricing with that in mind. Both title guides list the county tax as a seller cost by custom and the city tax as split between buyer and seller, but who pays is negotiable and belongs in the purchase agreement. We could not open Richmond’s or El Cerrito’s own code pages for this update, so confirm the current rates with escrow or the city before you rely on them. Our East Bay city transfer tax guide compares both counties, and the California transfer tax overview covers exemptions.

Point-of-sale rules: sewer laterals and other checks

EBMUD’s Regional Private Sewer Lateral program reaches into Contra Costa County through the Stege Sanitary District, which serves El Cerrito, Kensington and the Richmond Annex; it started there on October 17, 2011. In those areas a sale needs a compliance certificate or an approved alternative, and the same rule applies to remodels above $100,000 and water meter size changes. The rest of the county is not listed in the regional program, but ask the local sanitary district whether it has its own requirement.

Confirm the sewer agency from the parcel and the seller’s bills.
Check whether a valid certificate already exists before ordering work.
Get a contractor’s inspection and bid early, since the work and the verification test can outlast a short escrow.
Put the responsibility for the work and its cost in the contract.

Diamond may refer you to partners we work with; you’re free to choose any provider. Our sewer lateral certificate guide covers time extensions, condos and Stege’s own permits. State items such as smoke and carbon monoxide alarms and water heater bracing apply everywhere in the county.

Rent rules by city

State law sets the floor: under AB 1482, covered rentals in Contra Costa and Alameda counties may rise no more than 8.8% for increases taking effect August 1, 2026 through July 31, 2027, per the Attorney General’s chart. Three Contra Costa cities have their own rules.

City	Local rule	Allowed increase	What else a buyer should know
Richmond	Richmond Rent Ordinance, run by the Richmond Rent Program	1.62% Annual General Adjustment, adopted June 18, 2025, for increases from September 1, 2025; the latest figure posted when we checked in October 2026	Ask the Rent Program at (510) 234-7368 whether a unit is fully covered or under just cause rules only.
Antioch	Rent Stabilization Ordinance, effective November 11, 2022	60% of the change in the San Francisco-Oakland-Hayward CPI, capped at 3%; 2.28% for the posted periods from May 13 to September 11, 2026	One increase per 12 months; a rental registry is planned through business licensing; separate just cause and anti-harassment ordinances.
Concord	Residential tenant protection ordinance, first adopted in 2024 and amended effective May 22, 2025	5% a year after the 2025 amendment, up from 3%	CBS News reported that the 2024 version applied to homes and apartments built before 1995 and that, after the amendment, landlords with two or fewer properties are not bound by just cause rules; confirm which units the current ordinance covers.
Other cities and unincorporated areas	AB 1482 unless exempt	8.8% for August 1, 2026 to July 31, 2027	Check with the city before relying on state law alone.

Concord’s figures come from news coverage rather than the city’s own page, which we couldn’t open, so read the current ordinance before you buy there. For any occupied property, collect the rent roll, notices and tenant estoppels before removing contingencies; our East Bay rent stabilization comparison and AB 1482 guide for landlords go deeper. This is general information, not legal or tax advice; talk to a California real estate attorney or tax adviser about your situation.

Earthquake, fire and flood hazards

Earthquakes

The U.S. Geological Survey’s forecast for 2014–2043 gives the Bay Area a 72% chance of at least one magnitude 6.7 or larger earthquake, and the Hayward or Rodgers Creek fault a 33% chance. Faults in that forecast cross Contra Costa County: the Hayward Fault in the west county, and the Concord–Green Valley, Calaveras and Mount Diablo faults in the central county and San Ramon Valley.

The California Geological Survey’s Earthquake Zones of Required Investigation, covering fault zones, liquefaction and earthquake-induced landslides, include parts of Contra Costa County. Sellers must check the maps and give buyers a Natural Hazard Disclosure Statement, and cities and the county withhold permits in the zones until geologic or geotechnical investigations are done.

Fire hazard severity zones

CAL FIRE’s State Responsibility Area maps took effect April 1, 2024. For cities, CAL FIRE released Local Responsibility Area maps in four phases between February 10 and March 24, 2025, and sends owners to the local jurisdiction for a specific parcel. Check hillside parcels in Lamorinda, around Mount Diablo and in the San Ramon Valley on CAL FIRE’s viewer, and plan for a defensible space inspection where it applies; see our AB 38 inspection guide and fire hazard severity zone guide. Insurance availability is a separate question; shop coverage early.

Flood and the Delta

Bethel Island, Discovery Bay, Knightsen and other Delta communities sit low beside channels and levees, and the bay shore from Richmond to Martinez has its own flood areas. Look up the parcel on FEMA’s Flood Map Service Center, read the flood section of the Natural Hazard Disclosure, ask who maintains the nearest levee, and ask your lender early whether flood insurance will be required.

Water, sewer and getting around

EBMUD supplies drinking water to about 1.5 million people in a 332-square-mile area of 20 cities and 15 unincorporated areas; in Contra Costa its area runs from Crockett at the north edge east to Walnut Creek and south through the San Ramon Valley. EBMUD’s wastewater service, about 740,000 people, runs from Richmond south into Oakland. EBMUD describes its boundary as running east only to Walnut Creek, so Concord, the east county and other areas are served by other water and sewer agencies, so read the seller’s bills, and on rural parcels ask about wells and septic systems.

By our count from BART’s station list, 12 of BART’s 50 stations are in Contra Costa County:

West County: Richmond, El Cerrito del Norte and El Cerrito Plaza
Lamorinda and Central County: Orinda, Lafayette, Walnut Creek, Pleasant Hill/Contra Costa Centre, Concord and North Concord/Martinez
East County: Pittsburg/Bay Point, Pittsburg Center and Antioch

Capitol Corridor trains stop at Richmond and Martinez, and San Francisco Bay Ferry runs daily between Richmond and downtown San Francisco. The San Ramon Valley has no BART station, and the county’s mean commute was 35.3 minutes (Census, 2020–2024).

Property types buyers meet

Age-restricted living in Rossmoor: Rossmoor describes itself as a planned community for adults 55 or older, where at least one occupant must be 55 or older and no one under 18 may live. It covers about 1,800 acres, with 3,368 co-op manors, 3,245 condominium manors, 63 single-family homes and The Waterford’s 300 units with added services. Co-op and condo purchases follow each mutual’s own rules.
Hillside homes in Lamorinda, Kensington and the San Ramon Valley: slope, drainage, retaining walls, access and fire zone matter as much as the house.
Delta waterfront in Discovery Bay and Bethel Island: confirm dock ownership and permits, levee responsibility, flood zone and insurance before you commit.
Planned communities and newer subdivisions in San Ramon, Blackhawk, Brentwood and Oakley: read the association documents and ask whether the tract is in a community facilities district, because special taxes appear on the tax bill.
Small apartment buildings in Richmond, Concord and Antioch: local rent rules shape income; see our investment property services.
Farm and ranch land around Brentwood, Knightsen and Byron: zoning, water rights and wells, and any Williamson Act contract drive value.
Inherited homes: see probate and trust sales for court and trust timelines.

Buyers can start with buying a home in Contra Costa County, which explains how we set up a search across these areas.

Selling a home in Contra Costa County

The local items that change a seller’s costs and timeline are concentrated in the west county and in rental property. Work through them before you set a list price:

Confirm the jurisdiction from the parcel record; in Richmond or El Cerrito, estimate the city transfer tax and agree on the split.
Check the sewer agency, and in the Stege area get the lateral certificate under way early.
Review tenancy status for any rented unit in Richmond, Antioch or Concord, including notices and current rents.
Order the Natural Hazard Disclosure and, in high fire zones, the defensible space inspection.
Price from closed sales in the same community and property type, not the county median.

Diamond lists homes on the MLS and also reaches likely buyers through its own client database and targeted campaigns, within MLS and NAR Clear Cooperation rules. Our Contra Costa seller services page explains preparation and pricing, and a home valuation request starts with your address.

Questions people ask

What is the median home price in Contra Costa County?

C.A.R. reported $870,000 for existing single-family homes in September 2026, up 0.1% from $869,000 a year earlier, with sales down 5.7%. The figure covers very different markets, so price a home from nearby closed sales.

Which Contra Costa cities have a city transfer tax?

Richmond and El Cerrito, according to both Ticor Title’s 2026 guide and Old Republic Title’s Bay Area sheet. Every other city and unincorporated area pays only the county’s $1.10 per $1,000.

How much is the Richmond transfer tax?

0.7% of the price under $1,000,000, 1.25% from $1,000,000 to $2,999,999, 2.5% from $3,000,000 to $9,999,999 and 3% at $10,000,000 and above, plus the county tax. On an $870,000 sale that is $6,090 city tax and $7,047 in all.

Who pays transfer tax in Contra Costa County?

By custom the seller pays the county tax and the buyer and seller split the Richmond or El Cerrito city tax, per the title guides. It is negotiable, so write the split into the contract.

Do I need a sewer lateral certificate to sell in Contra Costa County?

In El Cerrito, Kensington and the Richmond Annex, yes, through the Stege Sanitary District under EBMUD’s regional program. Elsewhere it is not in the regional program, but check with the local sanitary district.

Does Contra Costa County have rent control?

Richmond, Antioch and Concord have local rules. Elsewhere AB 1482 caps increases on covered units at 8.8% for August 1, 2026 through July 31, 2027.

How much can rent go up in Antioch?

Antioch limits increases to 60% of the change in the regional CPI, with a 3% cap; the city posted 2.28% for its May to September 2026 periods. Only one increase is allowed in 12 months.

Is Rossmoor a 55+ community?

Yes. Rossmoor in Walnut Creek is an age-restricted community where at least one occupant must be 55 or older and no one under 18 may live, with co-ops, condominiums and a small number of single-family homes.

Are Alamo and Blackhawk part of Danville?

No. Alamo, Blackhawk and Diablo are unincorporated, so the county, not the Town of Danville, handles planning and building permits.

Which Contra Costa towns have BART?

Richmond, El Cerrito, Orinda, Lafayette, Walnut Creek, Pleasant Hill/Contra Costa Centre, Concord, North Concord/Martinez, Pittsburg/Bay Point, Pittsburg and Antioch, 12 stations in all. The San Ramon Valley has none.

Is Discovery Bay in a flood zone?

Flood zones vary from lot to lot in Delta communities, so a neighbor’s zone tells you little. Check the parcel on FEMA’s Flood Map Service Center, read the Natural Hazard Disclosure, and ask your lender about flood insurance.

Which faults affect Contra Costa County?

The USGS forecast includes the Hayward Fault in the west county and the Concord–Green Valley, Calaveras and Mount Diablo faults farther east. The state’s earthquake zone maps and the Natural Hazard Disclosure show whether a specific parcel is in a zone.

Who provides water in Contra Costa County?

EBMUD serves much of the west county, Lamorinda, Walnut Creek and the San Ramon Valley; other agencies serve Concord, the east county and other areas. The seller’s bills confirm the provider.

If you’re buying or selling in Walnut Creek, Lamorinda, Richmond, the Delta or anywhere else in the county, talk with Diamond Real Estate Group about the property and the rules that apply to it.

Sources & notes

Last reviewed October 2026 by Matthew Martinez.