Diamond Real Estate Group

Northern California Real Estate

Diamond Real Estate Group is a residential and vineyard real estate brokerage led by Matthew Martinez, Founder, CEO & Managing Broker (California DRE #01869679). We help people buy and sell homes, land, vineyards, investment property and bank-owned homes in Sonoma, Napa, Marin, Solano and Mendocino counties and San Francisco. The brokerage is Diamond Group Estates Inc, DRE #02163490.

Search homes for sale

Use the quick search below for current MLS listings across the North Bay, or open the full property search for more filters.

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Where we work

Communities

Our main markets are the six areas with a price on their card. Each has a county page with current listings. Prices are the median for existing single-family homes in September 2026, from the California Association of REALTORS® (C.A.R.).

Sonoma County

Napa County

Marin County

San Francisco

Solano County

Santa Clara County

Alameda County

Contra Costa County

San Mateo County

Monterey County

Mendocino County

$875,000 median, Sept 2026

Sonoma County

Nine cities; the rest, from The Sea Ranch to Glen Ellen, is planned by the county. Santa Rosa and Petaluma add a $2 per $1,000 transfer tax. See also Sonoma homes for sale.

$918,000 median, Sept 2026

Napa County

Five cities and towns. Under Measure J (1990), converting land the General Plan designates agricultural takes a public vote.

$1,678,750 median, Sept 2026

Marin County

Eleven cities and towns, plus Point Reyes National Seashore (about 71,000 acres). In unincorporated Marin, a short-term rental license ends when the property sells.

$2,054,000 median, Sept 2026

San Francisco

A consolidated city and county. Its transfer tax is tiered, and one rate applies to the whole price: 0.75% from $1 million to under $5 million.

$580,000 median, Sept 2026

Solano County

Seven cities, from Vallejo and Benicia to Vacaville and Dixon. Vallejo adds a $3.30 per $1,000 conveyance tax, and newer subdivisions often carry Mello-Roos taxes.

$480,000 median, Sept 2026

Mendocino County

Four cities: Ukiah, Fort Bragg, Willits and Point Arena. Coastal parcels follow a separate coastal zoning code, and Anderson Valley is one of its wine appellations.

Source: C.A.R. September 2026 sales and price report. Monthly medians in small counties swing.

What to expect from us

Experience

Every move starts with different priorities: a move-out date, a budget, a well, a loan that needs a short sale. We plan around the ones that matter most.

Local rules first

We check what changes a property's value before you commit: transfer taxes, fire-zone disclosures, rental limits, wells and septic.

Pricing from evidence

Pricing starts from comparable sales and the property's own records, and we tell you what we see, problems included.

Help with the work

Our concierge service connects sellers with providers for pre-sale repairs, staging and cleaning, and buyers with contractors for move-in work.

About Diamond Real Estate Group

Diamond Real Estate Group is the business name of Diamond Group Estates Inc, a real estate corporation licensed by the California Department of Real Estate (DRE), with Matthew Martinez as designated broker. We’re based in Sonoma County.

Brokerage
Diamond Group Estates Inc, DBA Diamond Real Estate Group, DRE #02163490
Designated broker
Matthew Martinez, DRE #01869679
Main counties
Sonoma, Napa, Marin, Solano, Mendocino, San Francisco
Property types
Homes, land, vineyards and wineries, multifamily, commercial, REOs and short sales

Diamond Real Estate Group

Buying with Diamond

Buying

We represent buyers of homes, land, vineyards and investment property, from a first home in town to acreage on a well and septic system. A purchase runs in five stages:

  1. Strategy: budget, timing and how much risk you’ll accept, such as a private well or a high fire-hazard zone.
  2. Search: current MLS listings in the towns that fit.
  3. Due diligence: well and septic reports, fire and flood zones, permit history, HOA documents. Get insurance quotes early; fire zone and roof age affect them.
  4. Offer: a price built from true comparables, with contingencies that protect you.
  5. Escrow: coordinating inspectors, the lender, title and insurance through closing.

Read how we work with buyers or our step-by-step guide to buying in Sonoma County.

Selling with Diamond

A sale starts with a pricing review built from recent comparable sales and the home’s records: permits, systems and what a buyer’s inspector is likely to find. Then we plan the preparation worth paying for, the marketing and the timeline.

Start disclosures early. In a High or Very High Fire Hazard Severity Zone, California’s AB 38 rule requires the seller to give the buyer documentation of a defensible-space inspection done in the six months before the sale, or a written agreement that the buyer will comply within a year of closing (State Fire Marshal).

Read how we sell homes, or request a home valuation.

Vineyards and wine country property

Vineyards, wineries and vineyard estates are a focus of our work, mostly in Napa and Sonoma. A vineyard is priced on more than the house: planted acres, varieties, vine age, water, permits and grape contracts each carry value, and the appellation affects what the fruit sells for.

In 2025, Napa County grapes averaged $6,635.85 a ton, the highest of any California crush district, against $2,762.88 for Sonoma and Marin (CDFA and USDA crush report). Napa County holds all or part of 19 American Viticultural Areas (AVAs), counting the six-county North Coast AVA, and Sonoma County has 19 inside North Coast.

Start with vineyards and wineries for sale in Napa and Sonoma, then the appellation guides for Sonoma County and Napa Valley.

REOs and short sales

We work both sides of distressed sales. A bank-owned (REO) home is sold by the lender after foreclosure; a short sale is sold by the owner for less than the loan, with the lender’s approval. Both usually sell as-is.

Buyers: we help you bid, inspect and plan for a longer approval period. See buying REOs and short sales.

Sellers: we explain short sales to homeowners who owe more than the home is worth, and list homes for lenders and asset managers. See REO and short sale listings. Homeowners should talk to their servicer and a HUD-approved housing counselor first.

Under Code of Civil Procedure §580e, a lender that approves a short sale of a one-to-four-unit home in writing generally can’t pursue the borrower for the shortfall. The federal tax break for forgiven mortgage debt on a main home lapsed for debt discharged after 2025 unless arranged in writing before 2026, and as of October 2026 it hadn’t been renewed (IRS Publication 4681), so ask a tax adviser first.

About Matthew Martinez

Founder, CEO & Managing Broker

Matthew Martinez founded Diamond Real Estate Group and leads it as CEO and managing broker. The DRE’s public record shows broker license #01869679, issued in February 2019, after he was first licensed as a salesperson in August 2010.

He came to real estate from sales and marketing. His work covers homes, vacant land, vineyards, multifamily and commercial property, including bank-owned homes and short sales. He describes his approach as data-driven and writes the guides on this site. Read Matthew’s full profile.

Guides for North Bay buyers

Each guide cites its sources and shows when it was last checked.

Real estate and local living

Our blog

Recent articles on North Bay towns, wine country and the housing market.

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Top Realtors for Vineyards and Wineries in N...

Licensed agents in Napa and Sonoma who list vineyard and winery property as a specialty, with verified DRE licenses, plus the rules and questions that matter.
published on October 23, 2026
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Best Realtors in Vacaville, CA (2026 Guide)

Licensed Vacaville, CA agents with verified DRE records, plus 2026 prices for 95687 and 95688, wildfire and heat checks, Nut Tree and Travis AFB.
published on October 23, 2026
default image

Best Realtors in Fairfield, CA (2026 Guide)

Licensed Fairfield, CA agents with verified DRE records, plus 2026 market data, Travis AFB and train station facts, special taxes and what to ask an agent.
published on October 23, 2026

Records first, then the property itself

We start with records: MLS comparable sales, county parcel and permit files, fire-hazard and FEMA flood maps and, for vineyards, crop and crush reports. They’re a starting point, not the answer.

Then we look for what records miss: the condition of the house, how the well performs, what neighboring land is zoned for, and whether the permits match what was built.

Questions about Diamond Real Estate Group

What is Diamond Real Estate Group?

A California brokerage representing buyers and sellers of homes, land, vineyards, investment property and bank-owned homes, led by Matthew Martinez. Its main markets are Sonoma, Napa, Marin, Solano and Mendocino counties and San Francisco.

Is Diamond Real Estate Group the same company as Diamond Group Estates?

Yes. Diamond Real Estate Group is the business name (DBA) of Diamond Group Estates Inc, DRE #02163490, and this website is diamondgroupestates.com. If you’re unsure which “Diamond” firm you’ve found, check the license number.

Who runs Diamond Real Estate Group?

Matthew Martinez, Founder, CEO and Managing Broker. He holds California broker license #01869679 and is the designated officer of Diamond Group Estates Inc.

Which areas do you cover?

Mainly Sonoma, Napa, Marin, Solano and Mendocino counties and San Francisco. The site also has county pages with listings for Santa Clara, Alameda, Contra Costa, San Mateo and Monterey counties.

Can I search homes for sale on this site?

Yes. The quick search above and the property search show current MLS listings. Ask us about any of them, including homes listed by other brokerages.

Do you work as a buyer’s agent in Napa?

Yes, in the City of Napa and across Napa County. Local rules shape many purchases: short-term rentals are generally not allowed in the unincorporated county, as the Napa County page explains.

Can you list and sell my home in Napa or Sonoma?

Yes: homes, land and vineyards in both counties. A listing starts with a pricing review from recent comparable sales.

Do you sell vineyards and wineries?

Yes, for buyers and sellers, mostly in Napa and Sonoma. We document water, vine health, permits, grape contracts and the appellation before pricing a property or writing an offer.

Do you handle REOs and short sales?

Yes. We represent buyers of bank-owned homes and short sales, explain short sales to homeowners, and list homes for lenders and asset managers.

How can I check your real estate license?

Search the California Department of Real Estate’s license lookup for Matthew Martinez (#01869679) or Diamond Group Estates Inc (#02163490). The record shows the license type, status and expiration date.

Let's get started

Diamond Real Estate Group

Tell us what you’re planning: a purchase, a sale, a vineyard or a distressed property. Send the property or area, your timing and your questions through the contact page, and we’ll set up a time to talk.

Diamond Real Estate Group is a DBA of Diamond Group Estates Inc, California DRE #02163490. Matthew Martinez, Designated Broker, DRE #01869679. Equal Housing Opportunity.

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