Fullerton ADU Market Update — August 2026: What's Active, What Just Closed, and What the Numbers Say
Fullerton has more ADU activity right now than most Orange County cities its size — and the spread is wide. This month's active inventory runs from an $839,000 historic downtown duplex to a $5.69 million view estate in Raymond Hills, with enough in between to give buyers at every price point something to consider.
Here's what the market actually looks like right now, broken down by status.
What's Active (7 Listings)
126 N Yale Ave — $839,000
A 1926 Spanish Colonial Revival duplex in the heart of Downtown Fullerton — this is the entry point for the Fullerton ADU market this month. The front unit is 2 bed/1 bath, the rear unit 1 bed/1 bath. Both have separate entrances, individual garages, and separate laundry. The ADU is currently tenant-occupied and rented, which means it arrives cash-flowing from day one. At $639/sqft on a 6,194 sqft lot steps from CSUF and the Santa Fe Train Depot, this is the kind of historic income property that draws both house-hackers and long-term investors alike.
2501 Santa Ysabel Ave — $1,480,000 (reduced from $1,580,000)
Two buildings on one lot in the Troy High School district — the main house plus a newly built 1,075 sqft ADU (3bd/2ba, built 2026). Both units are 3 bed/2 bath, which is about as close to symmetrical as you get on a two-on-a-lot deal. It's been on the market since May and took a $100,000 price cut in August. The ADU is vacant, meaning no tenant transition to manage for a buyer who wants to set their own lease terms from the start.
2943 San Juan Dr — $1,700,000
A 17,710 sqft lot near Fullerton Golf Course — which is a rare amount of land for this market. The property already has a permitted 1,042 sqft ADU (2bd/2ba) built in 2020. But the bigger story is the 675 sqft detached garage that the listing suggests could be converted to a future ADU, plus room to potentially build a 4-car garage with a separate approach. If that stacks out legally, you could be looking at a three-unit income property on one of the larger residential lots in the city. Understanding how the City of Fullerton classifies ADU projects — whether a garage conversion counts as new construction, an addition, or an alteration — will affect both your budget and your timeline here.
116–114 N Cornell Ave — $2,100,000
A four-unit income property in Fullerton's Historic Preservation Zone, zoned R2P. The front duplex (114A and 114B N Cornell) was completed in July 2026 and features two 3bd/2ba units (each ~996 sqft) with fully paid-off solar systems. There's also a remodeled 3bd/2ba main house and a 225 sqft studio apartment above the original garage. Four separate addresses, individually metered electricity, private laundry in each unit. This is a Downtown Fullerton property that functions like a small apartment complex, but without the apartment-complex price tag. R2P zoning in the historic district also provides some protection against the teardown pressure that hits plain R2 parcels in hotter sub-markets.
520 W Hermosa Dr — $2,560,000 (reduced from $2,650,000)
A Sunny Hills Estates home on a near-26,000 sqft lot next to Laguna Lake, featuring a 370 sqft private studio ADU with its own entrance, kitchenette, bathroom, and laundry hookups. The main house is ~2,928 sqft with a resort-style pool and a fully equipped cabana. At $874/sqft, this is the most expensive price per foot on the active list — reflecting the Sunny Hills premium and the lot size. The ADU here functions more as a guest suite than a dedicated income unit, but the lot has real expansion room for a buyer thinking longer-term.
1419 N Richman Knoll — $2,999,000 (reduced from $3,500,000)
An equestrian estate in the Green Acres community of North Fullerton, sitting on a full acre with a pool, spa, horse facilities, and RV parking. Two separate guest suites function as ADUs — a 592 sqft unit and a 371 sqft unit. The property has been active since January, now at 185 days on market with a $501,000 price reduction. For a buyer who needs equestrian facilities and multi-generational living on one property, this is a hard-to-replicate combination. The sitting time and price cuts signal a specific buyer profile, not a broad one.
2061 Skyline Dr — $5,690,000 (reduced from $5,970,000)
The top of the Fullerton market this month: a 7,752 sqft custom estate in Raymond Hills Estates with panoramic city, mountain, and hillside views. The ADU here is a 902 sqft Junior ADU attached to the main residence — large by JADU standards, with a kitchenette and separate access. The listing came on in July and took a $280,000 price reduction in early August. At this price point, you're buying the estate first and the ADU second.
Under Contract (2 Listings)
2016 E Santa Fe Ave — $1,099,888
A remodeled single-story home in the Troy HS district that went under contract after 64 days. The ADU here is a 325 sqft permitted Junior ADU with its own private entrance and bathroom. The listing came down from $1,250,000 — a $150,000 reduction before finding a buyer. Troy HS boundaries consistently move properties in Fullerton, even when the ADU is on the smaller side.
422 W Amerige Ave — $1,450,000
A true two-on-a-lot deal in Downtown Fullerton: a remodeled 3bd/2ba main house plus a brand-new 2026-built ADU (2bd/2ba, 1,000 sqft) already rented at $3,000/month. Total income potential advertised at $7,000/month. This one went under contract after 59 days and was marketed specifically to 1031 exchange buyers and investors. When a new-construction ADU is already rented and the income math works, buyers notice.
Pending (1 Listing)
1001 S Gilbert St — $1,190,000
A 12,613 sqft lot with a main 3bd/3ba house and a detached bonus structure complete with its own bathroom, kitchen, and AC. The listing notes the buyer should verify permitted uses for the structure. It went pending in 8 days — which tells you something. Properties with large lots and a separate habitable structure find buyers fast in Fullerton right now, even when the ADU classification isn't fully clean on the MLS.
Closed (2 Recent Sales)
436 E Truslow Ave — Closed at $2,045,000 (listed at $2,195,000)
A $150,000 discount after 236 days on market. This is a 4-unit property (2 single-family residences + 2 ADUs, all built 2025) with gross rents of $13,390/month. The buyer financed conventionally. At $454/sqft on 4,500 sqft of combined living space, the price-per-foot reflects the income-property nature of the deal rather than a comparable SFR valuation. The long sit time likely reflects buyer education more than a property problem — four-unit deals in Fullerton are rare and require a different underwriting framework than a typical SFR purchase.
2830 Anacapa Pl — Closed at $2,995,000 (full asking price)
This one closed full price after 61 days. A private estate near Laguna Lake with 5,105 sqft of living space, two detached guest residences (660 sqft and 551 sqft), a pool and spa, and a 23,400 sqft lot. The buyer financed conventionally. The two guest residences are the ADU story here — each with their own kitchen and separate access, functional as income units or multi-generational housing. A full-price close in 61 days sends a clear signal: well-priced, unique properties with real lot size are clearing without negotiation in this market.
What the Numbers Are Telling You
Fullerton's ADU market in August 2026 breaks into a few distinct sub-markets that don't always behave the same way.
Downtown Fullerton is the most active ADU cluster this month. The Yale duplex, the Cornell four-plex, and the Amerige two-on-a-lot are all competing for buyers in the $839K–$2.1M range. Amerige went under contract. Cornell is still sitting. Price-per-foot in Downtown ranges from $586 to $653 — tight compression for a market that runs from a 1926 duplex to a brand-new 2026 build. Compared to Anaheim's ADU market this August, Downtown Fullerton is producing similar price points with more historical character and a different buyer demographic.
The Troy HS district is its own pull. Santa Fe went UC after a price cut, and Amerige (also within Troy boundaries) went UC as well. Buyers paying attention to school district lines are moving on properties they might otherwise wait out.
Large-lot North Fullerton — Richman Knoll, Anacapa, Hermosa — is where the multi-gen and estate buyers operate. The Anacapa closed full price. Richman Knoll is sitting at 185 days. The difference: Anacapa was priced at $587/sqft on a massive lot in turnkey condition; Richman Knoll is at $689/sqft with a more specific buyer profile. Garden Grove has stronger comp depth and more volume — but Fullerton's large-lot segment closes at a higher price point when the buyer shows up.
Price reductions are a consistent theme. Four of seven active listings have taken cuts — ranging from $90,000 to $501,000. If you're a buyer, that means negotiation room exists on properties that have been sitting. If you're a seller, it means Fullerton's ADU market is pricing-sensitive even when the properties are exceptional.
The rental income story is sharpening. The Amerige Ave ADU rents at $3,000/month. The Truslow 4-unit is grossing $13,390/month. These are the numbers buyers are running — and lenders are counting ADU rental income more consistently than they used to, which is changing what buyers can actually qualify for. Fannie Mae's updated ADU income guidelines allow lenders to use ADU rent to help offset the mortgage payment — a meaningful shift for buyers trying to make the math work on two-on-a-lot properties in the $1.4M–$2.1M range.
The California HCD ADU Handbook is also worth bookmarking if you're evaluating properties with existing ADUs or potential conversion space — it's the baseline standard that governs what each unit type requires, and it's especially relevant when you're looking at something like the San Juan property where future density potential is part of the pitch.
Dylan Serna is an ADU specialist real estate agent serving Orange County and Los Angeles County. If you're buying or selling a property with an ADU in Fullerton, start here.
