The five highest-priced home sales reported in Tri-Valley, California for the week ending November 1, 2026, came to a combined $20.799 million, and all five were in Contra Costa County. Alamo had two of them, while Diablo, Danville and Pleasanton had one each.
The group spans more than seven decades of building, from a home that dates to 1941 to one finished in 2015, and lots ranging from well under half an acre to 5.20 acres of open hillside.
No. 1 — $7,000,000 · 1720 Alameda Diablo, Diablo, California
Known as “The White Castle,” the estate at 1720 Alameda Diablo sold for $7,000,000. It stands on 1.44 acres of nearly flat, landscaped grounds in the Diablo C.C. neighborhood, close to the entrance of the Diablo Country Club. The home was built in 1941, making it the oldest on this week’s list, and it has since been reworked by Jacobs & Co. and Badger Construction. The property last sold in 2020 for $4.6 million.
At 8,190 square feet, it is also the largest home in the group, and its seven bedrooms and nine bathrooms are the most of the five. The floor plan stays largely on one level and divides into two private wings. Five of the bedrooms are suites with their own baths, and the primary suite has a newly designed bath, enlarged closets and a gas fireplace.
For entertaining there is a wine room and a bar lounge, along with a great room and a formal dining room, and the entry has been enlarged. The updated kitchen has a breakfast bar, a breakfast nook and a pantry, and there is a separate prep kitchen as well. A tech center, a redesigned mudroom and two laundry rooms round out the working side of the home, which also has hardwood and tile floors and a gas fireplace in the living room.
Outside, a fenced pool and spa are heated by both gas and solar. There is seating around an outdoor fireplace and a playhouse for children, and the grounds were freshly sodded. The home has owned solar that serves both the home and the pool, a whole-house generator and an attached four-car garage.
The home went under contract 11 days after it was listed and sold just above its $6.995 million asking price. Margaret Combs of The Agency was the listing agent, and Mary Bonham, also of The Agency, represented the buyer. The sale ranks first this week and is one of two Top 5 listings for The Agency.
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No. 2 — $4,500,000 · 30 Saint Andrews Pl, Alamo, California
Set on a cul-de-sac in the Round Hill Country Club community, in Alamo’s Roundhill neighborhood, 30 Saint Andrews Place sold for $4,500,000. The ranch-style home was built in 1972 and has been expanded and extensively updated. An expansion in 2020 added a gym that opens through folding glass doors, a custom laundry room and a private guest suite with its own patio. The property last sold in 2008 for $1.279 million.
The home has five bedrooms, five bathrooms and 4,066 square feet, with the main living spaces, the bedroom suites and the gym on the main floor. Custom cabinetry surrounds the wood-burning fireplace in the living room, and the enlarged family room has a gas fireplace and French doors to the backyard. The primary suite has vaulted ceilings, its own access to the garden and a walk-in closet with a coffee bar. Its bath has heated floors, a marble steam shower and a freestanding air-jet tub. Upstairs, a large bonus level is fitted with a banquette built around a game table, a beverage bar and a bunk area.
At 0.39 acres, the lot is the smallest of the five, and much of it is given over to outdoor living. The pool and spa have been remodeled, and a pavilion completed in 2025 has a built-in grill, quartz waterfall counters, bar seating, heaters and a linear gas fireplace. There is also a sport court and a generous lawn. Vegetable beds and a cutting rose garden fill out the grounds. A paver driveway leads to the four-car garage, which has carriage-style doors and EV capability.
Jill Fusari of The Agency was the listing agent, which gave The Agency the listings on both of the week’s two highest-priced sales. Amanda Elhassan of Keller Williams Tri-valley represented the buyer.
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No. 3 — $3,500,000 · 4 Tyler Ct, Danville, California
The newest home on the list, 4 Tyler Court in Danville was built in 2015 in the Craftsman style. It sits on a cul-de-sac near downtown Danville and schools at all three levels, on a 0.41-acre lot whose backyard faces south. It sold for $3,500,000. The property last sold in 2016 for $1.975 million.
A two-story foyer opens the home, and natural light reaches through the interior. There are five bedrooms, five bathrooms and 4,007 square feet, with wood flooring throughout and two gas fireplaces. The primary bedroom is on the first floor, and a second bedroom with its own bath is also on the main level. An office and an upstairs loft that works as a bonus area add room beyond the bedrooms. The kitchen pairs white cabinets with granite slab counters and a glass tile backsplash, and its stove has six burners, a griddle and double ovens.
The backyard has a pebble-bottom pool and spa and a built-in barbecue station with a refrigerator and storage. There is a fire pit and an artificial lawn at the rear, along with a large vegetable garden and several fruit trees.
The home went under contract eight days after it was listed and sold at its full asking price of $3.5 million. Peter Bareiss of Re/max Accord was the listing agent, and Kelly McCoy of Bhhs Drysdale Properties represented the buyer.
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No. 4 — $3,199,000 · 2431 Alamo Glen Dr, Alamo, California
A Santa Barbara-style ranch, 2431 Alamo Glen Drive in Alamo sold for $3,199,000. Built in 1979, the single-story home sits on 0.58 acres, and visitors arrive through a Spanish-style courtyard framed by new professional landscaping. The property last sold in 2022 for $3.001 million.
The kitchen was recently renovated by MSK and has Wolf, Sub-Zero and Cove appliances, custom cabinetry and quartz countertops. It opens to the living and dining areas, and trifold Andersen doors lead from there to the backyard, where there is a pool and a court for pickleball and basketball. The home has four bedrooms, three bathrooms and 2,667 square feet, plus two spaces for work: a detached private office and a second office that can serve as a home gym. Engineered wood floors, a living room fireplace, improved drainage, an attached three-car garage and a Tesla charger complete the picture. The home is near Round Hill Country Club, as well as schools and parks.
Lesley Ramos of Compass was the listing agent, and Grace Oh of Bhhs Drysdale Properties represented the buyer.
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No. 5 — $2,600,000 · 6650 Johnston Rd, Pleasanton, California
Behind a gate on 5.20 acres, the largest lot of the five, 6650 Johnston Road in Pleasanton looks out on rolling hills, pastureland and the Black Hills. Oak trees dot the land, and deer, wild turkeys and hawks are regular visitors. There is space on the property for RV parking. Near Danville schools, it is about three miles from Blackhawk Plaza.
The home was built in 1989 and has six bedrooms, three full baths and a half bath across 3,808 square feet. A landscaped front yard with a fountain greets arrivals. In the kitchen, an island with pendant lights sits among quartz counters, stainless appliances, soft-close cabinetry and a bar area, and the baths have LED mirrors. Bonus rooms can work as an office, a gym or a nursery. Out back are a pool, a spa, a gazebo, a fire pit and a swing set, and the home has an attached three-car garage. The property last sold in 2025 for $2 million.
The home sold for $2,600,000, which was $600,000 above its $2 million asking price. Vicky Oberoi of Asset Real Estate was the listing agent, and Xingwen Chen of Keller Williams Realty represented the buyer.
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RealtyWire selected these transactions from publicly reported residential sales identified for the calendar week ending Sunday, November 1, 2026. The report may exclude private, off-market, delayed or nondisclosed transactions. Prices, property details and professional representation are reported as available at publication and may be updated following confirmation from transaction participants.
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