ADUs in Santa Ana
Backyard homes for Santa Ana, priced before you sign.
We design, permit and build standard ADU models across Orange County, Santa Ana included. You pick a model, we assess your lot, and you get one all-in price before you sign.
★ 4.9 on Google · 25+ reviewsCSLB License #1134744Design, permits and construction from one team
The models
Four standard homes, each with a price up front.
Starting prices include design, permitting and construction with standard finishes. Site work and utilities generally run $15,000 to $35,000 and are priced after we see your lot, and city permit fees are billed at cost. Model S, Model 1 and Model 2 are all 800 sq ft or less, so they fit even when the lot also gets a junior ADU. See what's included.
Around Orange County
Buildoly projects across Orange County.
Each pin is a Buildoly project in Orange County. See the full map.
Santa Ana ADU rules in plain English
What you can build in the City of Santa Ana.
The basics for a single-family lot in Santa Ana, under the ADU rules the City updated in 2025. Santa Ana is rewriting its zoning code in a citywide update that hasn't been adopted yet, so we confirm the rules in effect for your address when you apply.
How many
One ADU and a junior ADU
Under the City's ordinance, a single-family lot can have one ADU plus one junior ADU in the house, and an attached garage counts as part of the house. State law can allow other combinations, and we check which path fits your lot.
SAMC 41-194.2(C), (G); Gov. Code 66323Size
Up to 1,000 sq ft
An attached or detached ADU can be up to 1,000 sq ft, or 800 sq ft if the lot also gets a junior ADU. An attached ADU is also held to half the house's living space, but can always be at least 800 sq ft.
SAMC Table 41-194.3; 41-194.3(A), (B)Setbacks
4 ft from the side and rear
That applies to an attached or detached ADU; a junior ADU follows the house. An ADU rebuilt in the same place and size as a structure torn down to make room for it needs no setback.
SAMC Table 41-194.3; 41-194.3(G)Conversions
No size limit to convert
Converting an existing accessory building or part of the house has no size limit, and an existing accessory building can grow by up to 150 sq ft without meeting the standards for a new ADU.
SAMC 41-194.3(C), (D)Apartment lots
Up to eight detached ADUs
On a lot with an apartment building, you can convert non-living space into at least one ADU and up to a quarter of the unit count, plus up to eight detached ADUs, never more than the units already there. A planned apartment building can add up to two detached ADUs.
SAMC 41-194.2(D)-(F)Renting and selling
Rent it, don't sell it separately
An ADU can be rented, but generally not as a short-term rental of 30 days or less. It can't be sold apart from the house unless a qualified nonprofit built both under an affordable housing agreement with the City.
Gov. Code 66323(e); SAMC 41-194.2(H)Worth knowing in Santa Ana
Every ADU and junior ADU must be at least 220 sq ft.
We confirm the height limit, the front setback and any parking requirement with the City for your lot before we price anything.
Changing on January 1, 2027
SB 1117 limits the impact fee on an ADU over 750 sq ft to the area above 750 sq ft, in proportion to the main house, for up to two ADUs on a lot. ADUs of 750 sq ft or less still pay no impact fee.
AB 956 lets you build two new detached ADUs on a single-family lot through the state's approval path. On that path a city can cap each one at 800 sq ft.
Sources: Santa Ana Municipal Code 41-194.2 and 41-194.3 (with Table 41-194.3), as amended by Ordinance No. NS-3076, in effect March 6, 2025; City of Santa Ana, Comprehensive Zoning Code Update; California Government Code sections 66310 to 66342; SB 1117 and AB 956 (2026). Checked November 2026.
How it works
From your lot to move-in.
Step 1
Pick a model
Choose a model and finishes online, or book a free consultation to talk it through.
Step 2
Site assessment
We visit your lot, check utilities, access and the City's rules, and give you one all-in price before you sign.
Step 3
Design and permits
We finish the plans and run the permit with the City of Santa Ana's Planning and Building Agency from submittal to approval.
Step 4
Build and move in
We build on site and manage the job through final inspection and your certificate of occupancy.
Typical timeline: 8 to 12 months from start to finish. About 1 month of design, 2 to 4 months of permits and 3 to 5 months of construction. Your lot and the City's review times can move it.
Santa Ana ADU questions
What Santa Ana homeowners ask us.
Our models start at $165,000 for Model S, $195,000 for Model 1, $270,000 for Model 2, $360,000 for Model 3. Those are all-in starting prices for design, permitting and construction. Site work and utilities generally run $15,000 to $35,000, and we price yours after the site assessment, before you sign. City permit fees are separate: your city sets them and we bill them at cost. You start with $1,000, credited in full to your contract, and many of our clients finance the whole build through our lending partners, subject to credit approval. See what's included in the price.
Under the City's ordinance, a lot with a single-family house can have one ADU and one junior ADU. The junior ADU goes inside the house, and an attached garage counts as part of the house. A lot with several detached houses can have one ADU and no junior ADU. State law can allow other combinations, such as converting part of the house and also building a new detached ADU, and we check which path fits your lot.
An attached or detached ADU can be up to 1,000 sq ft, or 800 sq ft if the lot also gets a junior ADU. An attached ADU is also held to half of the house's living space, but can always be at least 800 sq ft. Converting an existing accessory building or part of the house has no size limit. Model S, Model 1 and Model 2 are all 800 sq ft or less.
Our typical timeline is 8 to 12 months from start to finish: about 1 month of design, 2 to 4 months of permits and 3 to 5 months of construction. Your lot and the City's review times can move it either way, and we give you a schedule for your address after the site assessment.
Santa Ana is rewriting its zoning code in a citywide update that hasn't been adopted yet, so we confirm the rules in effect for your address when you apply. Today's ADU rules come from the ordinance the City adopted in February 2025 (Ordinance No. NS-3076).
Yes. We build across Orange County, as well as Los Angeles County, San Diego and the Inland Empire. Each city has its own ADU rules and plan check, and we confirm them for your address. Enter your address in our quote tool to check that you're in our service area.
Where we build
We also build in these cities.
Each city page covers that city's ADU rules and who issues the permit. All cities.
Los Angeles County
Orange County
San Diego County
Inland Empire
See your price for a Santa Ana ADU.
Pick a model and tell us your address. After the site assessment you get one all-in number, before you sign.