Costa Mesa ADU Market Update – July 2026
Three properties. Three different ADU configurations. Nearly $1.5M separating the bottom of the market from the top. That's Costa Mesa's ADU market right now — wide, price-sensitive, and moving fast when the unit is right.
Here's what's active, what just went pending, and what closed — pulled directly from MLS as of July 1, 2026.
What's Active
1198 Dorset Ln, Costa Mesa 92626 — Listed at $1,399,900
This is the entry point for Costa Mesa ADU inventory right now. The home is a 5-bedroom, 3-bath, 1,962 sq ft SFR on a private cul-de-sac in the 92626 zip, listed June 19th at $713/sq ft. The ADU is a Junior ADU — 385 sq ft, 1 bed/1 bath, with a separate entrance, private stairway, and its own deck on the second floor. It's attached to the main home and shares utilities.
A few things worth noting here. First, this is a trust sale — the seller has not occupied the property, which typically means less friction on price and fewer emotional comps conversations. Second, the JADU configuration is the most common ADU type you'll see at this price point in Costa Mesa. The unit is currently unoccupied and not rented, which means a buyer gets flexibility on how to deploy it — long-term tenant, family member, or simply extra living space.
The cul-de-sac location near Paularino Elementary (Newport Mesa Unified) and the no-HOA structure add real appeal for families and investors alike. No solar, no pool — straightforward operating costs.
At $1.4M, the income math on a 385 sq ft JADU is modest. You're looking at $1,500–$1,900/month long-term for a junior unit of this size in this zip. That covers roughly $18,000–$23,000/year — meaningful supplemental income, but not a cash-flow engine on its own. The value proposition here is lifestyle flexibility plus appreciation, not pure yield.
What Just Went Pending
2782 Mendoza Dr, Costa Mesa 92626 — Listed at $2,325,000
This one went pending in 7 days. Listed June 12, under contract June 19. That's the number that matters most in this property's story.
The home is a 4-bedroom, 3-bath, 2,014 sq ft SFR in the Mesa Del Mar neighborhood — one of the more established pockets in central Costa Mesa. The standard detached ADU is 499 sq ft, 1 bed/1 bath, built in 2026 with city permits, its own separate address, and a separate electric meter. It sits at the rear of a T-shaped lot with stone pavers, an outdoor fireplace patio, a quartz slab bar, and a built-in BBQ — essentially its own outdoor living environment.
At $1,154/sq ft on the main home, this is pricing at the upper end of Mesa Del Mar. What justifies it: the ADU is brand new (2026-built), fully permitted, detached, and income-ready from day one. The seller will cooperate with a 1031 exchange, which is a clear signal this is being marketed to investors as much as owner-occupants.
Seven days to pending is not luck — it's what a new permitted detached ADU does to a property's buyer pool. Permitted units attract conventional buyers, FHA buyers (this one accepts Cash to New Loan only), and investors who know a lender can actually count the income. Unpermitted units attract a fraction of that pool and take longer — often much longer.
For long-term rental income, a new detached 499 sq ft 1/1 in Mesa Del Mar is realistically $2,200–$2,600/month. That's the income a buyer is underwriting, and Costa Mesa's short-term rental ban means the Airbnb math is off the table — this is purely a long-term income story. If you're using that rental income to help qualify for the mortgage, exactly how lenders count ADU rental income at underwriting is worth knowing before you write an offer.
What Closed
212 E 19th St, Costa Mesa 92627 — Listed at $2,995,000, Closed at $2,915,000
The top of the market, and a useful data point on how Eastside Costa Mesa prices when the ADU is large, new, and fully detached.
This is a 5-bedroom, 4-bath, 2,578 sq ft dual-residence property on an 8,100 sq ft lot in the Eastside Central neighborhood — minutes from the beach, Horace Ensign Middle, and Newport Harbor High. The detached ADU was added in 2025: 938 sq ft, 2 bed/2 bath, full kitchen, separate entrance, and private patio. The property was designed and built by local firm Abode Design + Build, with premium finishes throughout — Calacatta Venato porcelain countertops, wide-plank vinyl flooring, smart-home integration, integrated audio.
It listed at $3,095,000 in January, dropped to $2,995,000 in March, and closed June 1st at $2,915,000 — 97.3% of final list price after 90 days on market. The 90 DOM reflects both the price point and the market's adjustment period following the January list. Cash to New Loan only. Buyer's agent received $87,450 in concessions.
The 938 sq ft two-bedroom ADU in Eastside should rent at $3,000–$3,500/month long-term. That's meaningful income against a $2.9M purchase — though at this price point, buyers are underwriting appreciation and lifestyle as much as yield. How a home like this gets valued at appraisal depends heavily on whether the appraiser applies the income approach — and with a permitted, 2025-built detached 2/2, they can.
What the Numbers Are Telling Us
ADU type is doing the most work on price. The spread from $1.4M (385 sq ft JADU) to $2.9M (938 sq ft detached 2/2) is almost entirely explained by ADU configuration — size, attachment status, bedroom count, permit year, and whether the unit is income-ready from day one. How your home with an ADU gets priced when you sell comes down to exactly these variables.
New permitted detached ADUs move fast. The Mendoza Dr property — new 2026-built detached unit, separate address, separate electric meter — went pending in 7 days. The Eastside property with a 2025-built detached unit sat 90 days, but that's a function of the price point and January list, not the ADU. Permitted units attract a deeper buyer pool and support the income approach at appraisal. Unpermitted units don't.
No HOA on any of these. All three properties carry $0 HOA — a consistent characteristic of the Costa Mesa ADU market that keeps operating costs clean and DSCR loan underwriting simpler.
Long-term rental income only. Costa Mesa's short-term rental ban is in effect across the city. Any income strategy here runs on long-term tenants — which is still strong, but buyers need to underwrite accordingly.
Costa Mesa prices at a premium vs. comparable ADU markets. The Mendoza Dr deal at $2.3M for a new detached 1/1 ADU would run $900K–$1.1M in Anaheim or Garden Grove for a comparable configuration. The land basis, school district (Newport Mesa Unified throughout), and coastal proximity drive that gap. The income math is different, but so is the appreciation story.
If you're buying or selling a Costa Mesa property with an ADU — or trying to figure out where your property fits in this market — I track these comps every month. The June 2026 update has additional context on how permitted ADU potential was priced even before a unit was built. Call or text to talk through the numbers on your specific property.
If you plan on buying or selling ADU potential or already built ADU property - call or text Dylan Serna at (714) 860-2868 to schedule a consultation.
Dylan Serna | ADU Specialist | adurealtor.net
