Costa Mesa Multi-Unit Market Update — August 2026: What's Active, What Just Went Under Contract, and What the Numbers Are Telling Investors
Costa Mesa is one of the most interesting multi-unit markets in Orange County right now — and also one of the most complex to read correctly. You've got Eastside properties going under contract in five days while some Westside quads sit with compressed cap rates and rent-controlled tenants. You've got a 24-unit apartment trading at nearly $10 million alongside a vacant duplex priced at $1.395M. And you've got a handful of single-family and small-lot properties where ADU eligibility is quietly becoming a real pricing factor.
Here's a full look at what the data shows as of August 7, 2026 — active inventory, what just went under contract, what's pending, and the one closed comp that tells you something real about where the market is right now.
The Active Inventory: 16 Properties, Wildly Different Profiles
Active inventory across Costa Mesa income properties spans from a $1.585M vacant duplex on the Westside to a $9.595M 24-unit apartment on Avocado. That range is meaningful — it's not just a price difference, it's a completely different underwriting exercise for each end of the spectrum.
Here's a breakdown of what's sitting:
Small multi (2–4 units):
726 Weelo Dr — $1.585M | 2-unit vacant duplex, large lot with ADU potential. This is the entry-level buy for someone who wants to house-hack or add a third unit before stabilizing the income. Vacant = no tenant friction at close, though vacant also means no day-one cash flow.
3045 Coolidge Ave — $1.65M | Triplex, 4.9% cap rate, bankruptcy sale. That cap rate is genuinely interesting in this market. The bankruptcy context explains the motivation — and the discount. A buyer who does the due diligence correctly upfront and understands how to clear title through a bankruptcy proceeding could buy a 4.9% cap asset in Costa Mesa at a basis that's hard to replicate otherwise.
735 W 18th St — $1.85M | 4-unit, Westside. Price per unit is reasonable for the market, but Westside quads come with the standard OC small-multi reality check: confirm which units (if any) are subject to AB 1482 just-cause protections before you write the offer.
408 Ford Rd — $1.895M | Triplex, cap 3.91%, rent controlled. At 3.91%, you are buying this as an appreciation play, not a cash flow play. The rent-controlled overlay matters here: understanding your options for legally repositioning tenancies in Costa Mesa is essential before underwriting any upside on this one.
2976 Royal Palm Dr — $2.15M | 4-unit, rent controlled. Similar profile to Ford Rd. Current income is what it is — the long-term play here depends on unit turnover and eventual rent resets.
1635 Coriander Dr — $2.15M | 4-unit, Mesa Verde, NOI $80,457. This is the cleanest buy in the quad price range. Mesa Verde location, documented NOI, no rent control flags at this address. At $2.15M on $80,457 NOI, you're at roughly a 3.75% cap — compressed, but Mesa Verde quads rarely trade at anything better in this market.
2940 Peppertree Ln — $2.25M | 4-unit, cap 3.2%. This is the market's boldest ask. A 3.2% cap in Costa Mesa requires a conviction bet on significant rent growth and/or appreciation — buyers underwriting this correctly are probably modeling to a 5–7 year hold with multiple unit turnovers before the income picture changes.
1925 Wallace Ave — $2.6M | 4-unit plus separate development lot. This is a two-part buy: you're acquiring the income property and a lot with its own development potential simultaneously. The upside on the lot is real, but pricing is speculative relative to the current cash flow.
2653 Santa Ana Ave — $3.199M | 4-unit on a large lot with ADU potential. Large-lot quads in Costa Mesa that can add a fifth unit via ADU permitting are a different asset class than standard quads. California's HCD framework makes it increasingly difficult for cities to block ADU construction on income-producing lots — which means a permitted ADU addition here could meaningfully change the income profile of this property over a 24-month horizon.
131 E 21st St — $3.49M | 5-unit, Eastside. Eastside location is the story here. You're paying a submarket premium, and the data from what's going under contract (more on that below) suggests the Eastside premium is very much alive in August 2026.
Mid-size multi (7–14 units):
758 W 20th St — $4M | 7-unit, combination of new construction and renovated units, cap 4.53%. A 4.53% cap with new and renovated stock is a reasonable entry point for a buyer who wants a more stabilized, lower-maintenance asset in the Costa Mesa multi-unit corridor.
2256-2260 Maple St — $4.4M | 10-unit, cap 4.12%. Mid-size apartment, mid-range cap. The price reflects the size and stability — this isn't a value-add play, it's a hold-and-collect acquisition for a buyer who wants scale without the complexity of a true apartment building.
2029 Harbor Blvd — $4.995M | 13-unit mixed-use, cap 5.05%. The highest cap rate in the active inventory, and it comes with the mixed-use complexity that tends to repel buyers who aren't comfortable underwriting retail/commercial components alongside residential units. For an investor who is comfortable with it, 5.05% in Costa Mesa on a mixed-use asset is not a bad entry.
Large scale:
291-293 Avocado St — $9.595M | 24-unit apartment building, cap 4.66%. Institutional-adjacent pricing but still a private-market buy. At 4.66% cap on a 24-unit, the debt service coverage at today's rates is tight — buyers here are likely either all-cash or bringing significant equity to keep the DSCR where conventional or DSCR lenders want it.
ADU/SFR hybrid:
3097 Molokai Pl — $2.995M | Single-family residence with a newly constructed ADU. This is the buyer who wants to own in Costa Mesa at a price point that would otherwise put them in a quad — but instead of four small units, they get one primary residence plus one high-quality ADU. For the right buyer (owner-occupant, house-hacker, or investor willing to hold for the long-term appreciation story), this property reads completely differently than a traditional income property. How a home with an ADU gets appraised at this price point is worth understanding before writing an offer — the appraiser's approach to comparable ADU sales in Costa Mesa will drive the bank's valuation.
What Just Went Under Contract
Four properties went active-under-contract recently, and the speed on two of them tells the real story about where demand is concentrating:
2209 Elden Ave — $2.499M | 4-unit, Eastside. Listed July 28. Under contract August 2. Five days on market. That is not an accident. Eastside Costa Mesa 4-units at the $2.5M price point are exactly what the most motivated buyers in this market have been tracking and waiting for. When one hits, it moves.
136 E Bay St — $3.9M | 8-unit, Eastside. Listed June 12. Under contract August 6. It sat longer — 55 days — but it closed out the demand side of an Eastside 8-unit that opened at nearly $4M. The buyer pool for an $3.9M income property is inherently smaller, so 55 days to contract is a respectable result.
681 Victoria St — $3.495M | 7-unit. Under contract, fewer details on timing, but priced firmly in the mid-market range where institutional-adjacent buyers and experienced private investors overlap.
753 Scott Pl — $1.395M | Duplex. Entry-level two-unit going under contract is consistent with what we see across OC right now — the occupied vs. vacant question at this price point often matters less than the income potential and the basis, because the buyer pool includes both investors and house-hackers who will live in one unit.
What's Pending
Five properties currently pending escrow:
2171 Pomona Ave — $1.349M | Duplex. The lowest price point in the pending stack, and probably the highest competition-per-buyer ratio — duplexes in Costa Mesa at $1.35M don't last.
1920 Wallace Ave — $3.19M | 8-unit, Westside, 7 days on market. Fast absorption on a Westside 8-unit — this one likely went at or very close to list.
2525 Elden Ave — $3.6M | 5-unit with ADU potential, 6 days on market. Six days. Again, Elden Ave. The Eastside corridor is producing the fastest-moving inventory in the market right now. The ADU potential flag on this one probably added to the urgency — buyers in the 2026 market understand that an additional unit is a real income event, not just a hypothetical.
317 University Dr — $2.9M | Triplex. Mid-tier, Eastside-adjacent.
311 W Wilson St — $5.586M | 14-unit, 38 days on market. The longest pending in the group, which makes sense — a $5.6M apartment building takes longer to underwrite, finance, and negotiate. 38 DOM on a property at this price point in Costa Mesa isn't a distress signal, it's a normal timeline for a buyer doing a proper institutional-level due diligence process.
The One Closed Comp
782 W 18th St — Listed at $1,749,000. Sold at $1,600,000. Closed July 30, 2026. 23 days on market.
That's an 8.5% discount to the original asking price — meaningful in a market where some comparable listings are priced with essentially no negotiating room. A few things to note:
First, Westside 18th Street is not Eastside Elden Avenue. The submarket difference in Costa Mesa is real and it shows up in pricing and negotiation leverage. Second, 23 DOM before going under contract suggests this wasn't a bidding war — the seller had to come to the buyer. Third, the gap between list and close ($149,000) is large enough that it likely reflects either an aggressive initial ask, a condition issue that surfaced in inspection, or both.
For sellers currently priced at or above $1.7M on Westside multi-unit properties: this comp matters. Pricing a multi-unit property correctly in Costa Mesa in August 2026 depends on which submarket you're in — and this comp is a Westside data point that any appraiser or buyer's agent will use.
For buyers, under Fannie Mae's appraisal guidelines, the appraiser needs to document comparable sales to support the income approach — and in a market where Eastside and Westside can differ by 10–15% in effective pricing, submarket matters as much as unit count.
What This Means for Sellers
The Costa Mesa multi-unit market is bifurcated in a way that makes blanket advice useless. If you own an Eastside quad or 5-unit — the 2209 Elden comp (5 DOM) and 2525 Elden pending (6 DOM) are telling you that your buyer is already in the market, already motivated, and probably has been watching for a property like yours for months. You have real leverage right now if you're priced correctly.
If you own a Westside quad with rent-controlled tenants and a cap rate below 4%, the story is different. The 782 W 18th closed comp is the benchmark. Buyers are negotiating. The spread between ask and close is real. That doesn't mean it's a bad time to sell — Costa Mesa inventory is still relatively thin — but it does mean that how the property gets priced, staged, and marketed matters more when you're in a submarket where the buyer has comps on their side.
What This Means for Buyers
The speed of absorption on Eastside properties — and on anything with ADU potential — suggests you cannot take a slow approach in this market. The Elden Avenue properties are the tell: serious buyers who found those listings had underwriting frameworks already in place, and they moved within days.
Before you write an offer on any Costa Mesa multi-unit, the checklist is specific. Tenant status, lease terms, rent control applicability, utility metering, permit history on any ADU or addition, and a realistic income model based on actual Costa Mesa rents — not statewide averages. The pre-offer framework I run on every OC and LA investment property is the same one that keeps buyers from discovering problems after they're in escrow with non-refundable deposits.
For investors planning to add an ADU to a Costa Mesa income property after acquisition: the city's ADU permitting process is manageable, and California's HCD framework limits what Costa Mesa can restrict. But do this analysis before you close — not after. The lot dimensions, existing setbacks, and unit count all affect what's actually permitted, and the ADU income projection that makes the deal pencil needs to be based on permitted potential, not wishful thinking.
The Takeaway
Costa Mesa multi-unit in August 2026 is a market of extremes: Eastside properties selling in days, Westside comps closing at 8.5% below ask, cap rates ranging from 3.2% to 5.05% within the same city. The investors doing well here are the ones who understand the submarket distinctions, underwrite to actual income (not pro forma), and move fast when an Eastside property hits the market at a reasonable price.
For sellers on the Eastside or with ADU-eligible lots, the window is open. For Westside sellers with rent-controlled, under-market inventory, the buyer is still there — but they're negotiating, and the 782 W 18th comp is in their back pocket.
For a current read on what your Costa Mesa multi-unit is worth, or to build a search around the right profile of income property in OC, reach out directly at (714) 860-2868.
Dylan Serna | ADU Specialist | DRE #02217359 Call or text: (714) 860-2868 | adurealtor.net | Free ADU Seller Kit
