Detached ADU Construction
A freestanding backyard home with its own foundation, roof and utility connections, sized and placed to respect setbacks, oak trees and the slope of your Santa Clarita lot.
Learn More
SCV accessory dwelling units
ADU Builder in Santa Clarita, California
Accessory dwelling units are what we do in the Santa Clarita Valley: design, permit and construction, from Valencia tract homes to Sand Canyon horse properties and the unincorporated communities that LA County permits.
4 ftMost a city can require for ADU side and rear setbacks
60Days a city has to act on a complete ADU application
500Square feet: the size cap for a junior ADU
750Square feet: ADUs under this size skip impact fees
California ADU law (Government Code 66310-66342). Coastal, hillside and fire-zone lots can carry extra local rules.
ADU services
ADU Services in Santa Clarita
Every ADU project here needs the same core pieces: a design that fits the lot, an approved permit from the city or the county, and a build that ties cleanly into the existing water, sewer and power. We handle each piece, and you can see what each one covers below.
Attached ADU Construction
A unit added to the side or rear of the house, sharing a wall but keeping its own entrance, often the smart choice on narrower Valencia and Saugus tract lots.
Learn More
Garage Conversion ADU
The garage you park junk in becomes a permitted studio or one-bedroom, keeping its slab and shell and gaining insulation, windows, plumbing and a kitchen.
Learn More
Junior ADU (JADU)
A compact unit of up to 500 sq ft carved out of the existing house or attached garage, with its own exterior door and an efficiency kitchen.
Learn More
Above-Garage and Two-Story ADU
A second-story ADU over a garage or a two-story detached unit, useful where yard space is short but the lot can handle the height.
Learn More
Prefab ADU Installation
Modular or panel-system units from a factory, placed on a foundation we pour, with the local permit, crane day and hookups handled by us.
Learn More
Multifamily ADU Construction
Adding detached units or converting storage and garages on duplex, triplex and apartment lots under the state's multifamily ADU rules.
Learn More
ADU Design and Plans
Measured site plans, floor plans and elevations drawn for Santa Clarita or LA County plan check, with your layout and budget in mind.
Learn More
ADU Permits and Approvals
Preparing and shepherding the permit file through the city's Planning Division and Building & Safety, or through LA County for unincorporated parcels.
Learn More
ADU Foundations and Utilities
The buried and behind-the-wall scope: footings, grading, sewer and water lines, a bigger electrical service and sprinkler piping on lots that require it.
Learn More
ADU Kitchens and Bathrooms
Full and efficiency kitchens plus bathrooms planned for small floor plans, with plumbing and venting laid out early to control cost.
Learn More
Not sure which ADU fits your lot?
Tell us about the property and what you want the space for. We will reach out and talk through the options that fit your lot and local rules.
Request a ConsultationExplore All Services
ADU builders in Santa Clarita
An ADU Contractor Built Around the Santa Clarita Valley
Santa Clarita ADU Builder Pros handles the whole path from first sketch to final inspection: site review, design drawings, the permit file, foundations, utilities and the finished unit. We work on backyard cottages, garage conversions, junior ADUs inside the house, second-story units over garages and ADUs added to apartment lots.
The valley is not one housing market. Valencia, Saugus, Newhall and Canyon Country were separate communities before the city incorporated in December 1987, and each still has its own mix of lot sizes and home ages. Then there are the places outside city limits, such as Stevenson Ranch and Castaic, where Los Angeles County is the permitting agency. Knowing which set of rules applies to your parcel is the first thing we sort out. Our job is to turn the space you already have into a legal second home that fits the lot, passes plan check and gets built without surprises in the ground.
See How We Build ADUsADU project types
ADU Project Types on Santa Clarita Lots
Different parts of the valley lend themselves to different ADU types. These examples show how lot shape, home age and the permitting agency point toward a particular kind of unit. They describe typical fits, not specific jobs, and every parcel still gets its own review.
Garage Conversion on an Older Saugus Tract Lot
Many older Saugus houses have an attached two-car garage facing the street and a modest rear yard. Converting that garage keeps the backyard open, reuses the existing structure and, because the city does not require replacement parking for lost garage spaces, avoids a new carport or driveway.
What is involved:
- Design
- Permits
- Slab and insulation
- Plumbing
Detached ADU on a Sand Canyon Equestrian Parcel
Larger ranch lots in Sand Canyon often have room for a freestanding guest house away from barns and arenas. The Special Standards District, oak trees and fire hazard mapping all shape placement, and long utility runs from the main house become a central part of the scope.
What is involved:
- Site planning
- Oak review
- Utility trenching
- Fire-zone construction
Junior ADU Inside a Bridgeport Cape Cod Home
Bridgeport's Cape Cod-style homes sit on compact Valencia lots where a backyard unit may not fit comfortably. Fitting a JADU (500 sq ft at most) within the existing walls, with a separate outside door, adds a rentable or family suite without changing the street view.
What is involved:
- Interior layout
- Efficiency kitchen
- Separate entry
- Permits
Detached ADU on a Stevenson Ranch Hillside Lot
Stevenson Ranch sits in the Santa Susana foothills and is permitted by Los Angeles County, not the city. Sloped rear yards there often need a stepped or engineered foundation and careful drainage, and the county's two-stage review through Regional Planning and Public Works sets the permit timeline.
What is involved:
- Soils report
- Foundation
- County permits
- Drainage
City or County: Who Permits Your Santa Clarita ADU
Inside city limits, the Planning Division reviews every ADU and JADU before Building & Safety starts plan check. Outside them, in Stevenson Ranch, Castaic, Val Verde, Agua Dulce and the unincorporated land west of I-5, LA County Regional Planning approves first through EPIC-LA, then Public Works issues building permits. The city's Residency Status Verification Tool tells you which side your parcel is on.
How ADU permits work in Santa ClaritaHow an ADU Gets Built in Santa Clarita
Every project runs through three stages. The order never changes, but how long each takes depends on the lot, the unit type and whether the city or the county is reviewing it.
01
ADU Site Review and Design
We look at the parcel, confirm the jurisdiction, check for oaks, slope, fire zone and HOA rules, then draw a site plan, floor plan and elevations that fit those limits and your goals.
02
ADU Permits and Plan Check
We submit the drawings and supporting reports, answer correction comments and keep the file moving. By statute, reviewers get 15 business days for the completeness call, then a 60-day window to rule on a complete file.
03
ADU Construction and Final Inspection
Crews pour footings, set utilities, frame, pass rough inspections, then close walls and install finishes. A signed final inspection card marks the end, and the ADU can be occupied.
Why build an ADU in Santa Clarita
Why a Backyard ADU Makes Sense in Santa Clarita
Most of the city is single-family tract housing, and many of those lots have a usable side yard, a deep rear yard or an attached two-car garage. That is exactly the kind of space state ADU law was written to open up. Families here use ADUs for aging parents, adult children who work in the valley, or long-term tenants.
The city also makes the rules fairly clear. Its current ADU handout for single-family homes lists the unit types allowed by right and says the city sets no parking requirement for ADUs or JADUs. Every ADU and JADU must have its own exterior entrance, and review is ministerial, meaning no public hearing and no neighbor vote on a compliant plan.
- One house lot can hold three units by right: a conversion, a JADU and a new backyard ADU
- The city's 2026 ADU handout lists no parking requirement for ADUs or JADUs
- An ADU can be rented separately on terms of 30 days or more
- No impact fees apply to an ADU of 750 sq ft or less
- Garage space removed for a conversion does not have to be replaced
Santa Clarita Lot Types and the Rules That Shape an ADU
Flat tract lots in Valencia, Saugus and much of Canyon Country are the simplest ground to build on. The questions there are about access for equipment, where the sewer lateral runs and whether an HOA has a say on exterior finishes. Hillside parcels in Tesoro del Valle, Stevenson Ranch and the upper reaches of Canyon Country add grading, retaining walls and soils reports to the scope.
Two neighborhoods carry their own overlay. Sand Canyon and Placerita Canyon each have a Special Standards District in the city's Unified Development Code, written to protect their equestrian, rural character. Oaks are another local factor: the city's Oak Tree Preservation ordinance protects them, and the Urban Forestry Division handles oak inspections, so a protected tree near the build area changes where the ADU can go.
Fire hazard mapping matters more than it used to. CAL FIRE released new Fire Hazard Severity Zone maps for Los Angeles County in March 2025, and the Very High zones in the Santa Clarita Valley grew. A lot inside a High or Very High zone can bring Chapter 7A ignition-resistant construction and defensible-space requirements into the design.
Santa Clarita ADU Cost Drivers
Two ADUs with identical square footage can land far apart on price, which is why a price list would mislead you. The biggest swing factor is the type of unit. Converting an attached garage reuses a slab, walls and a roof. A new detached unit starts from bare dirt and needs its own foundation, framing, roof and utility runs.
Site conditions come next. A long trench from the street to a backyard unit, a sewer lateral that has to be upsized or rerouted, an electrical panel that cannot carry a second kitchen, or a slope that calls for a stepped foundation will each add real money. Fire-zone construction details, such as ember-resistant vents and ignition-resistant siding, add to materials.
Finishes and size round it out. Kitchens and bathrooms concentrate cost in a small footprint, so cabinet, counter and fixture choices move the total more than an extra hundred square feet of bedroom. Fees vary too: a unit at or under 750 sq ft avoids impact fees under state law, which is one reason many owners hold their design to that line.
Santa Clarita service areas
ADU Builders Across the Santa Clarita Valley
We work in every part of the city, including Valencia, Saugus, Newhall and Canyon Country, plus neighborhoods with their own character such as Sand Canyon, Placerita Canyon, Fair Oaks Ranch, Plum Canyon, Bridgeport and Tesoro del Valle. Outside city limits we build in Stevenson Ranch, Castaic, Val Verde and Agua Dulce under LA County permits.
Santa Clarita area
ADU Builder in Tesoro del Valle
See Tesoro del Valle
Santa Clarita area
ADU Builder in Stevenson Ranch
See Stevenson Ranch
Santa Clarita area
ADU Builder in Castaic
See CastaicFAQs
Santa Clarita ADU Questions
What is a realistic ADU permit timeline in Santa Clarita?
It depends on how complete the first submittal is and how many correction rounds plan check needs. State law requires the agency to decide completeness within 15 business days and to act on a complete application within 60 days. Design time before submittal and correction turnaround after it add to the calendar, so we plan for both.
Can I rent out my ADU in Santa Clarita?
Yes. The city's ADU guidance says an ADU may be rented separately from the main house, but it cannot be sold or conveyed on its own, and rentals must be for 30 days or longer. Short-term vacation rentals are not allowed.
Do I need parking for an ADU in Santa Clarita?
The city's 2026 ADU handout for single-family homes states there are no parking requirements for ADUs or JADUs. If you convert a garage, the lost spaces do not need to be replaced. For unincorporated county parcels, we check LA County's standards, which are also bounded by state parking limits.
Is owner occupancy required for a Santa Clarita ADU?
No. State law bars cities and counties from requiring owner occupancy to build or rent an ADU. The exception is a junior ADU that shares a bathroom with the main house: in that case, the owner must live in either the house or the JADU.
Is my home in Santa Clarita city limits or LA County?
Check before you design anything. Stevenson Ranch, Castaic, Val Verde, Agua Dulce and parts of Valencia west of I-5 are unincorporated LA County. The city has added neighborhoods through annexation, including Plum Canyon in 2018 and Tesoro del Valle in 2022, and its Residency Status Verification Tool confirms a parcel's status.
Will an ADU raise my property taxes?
Somewhat. The Los Angeles County Assessor treats the ADU as new construction and stacks its value on top of your current assessed value; the house is not reassessed. Your tax bill goes up by the assessed value of the ADU, not the house. The assessor makes that determination after the unit is finished.
What if my lot is in a Very High Fire Hazard Severity Zone?
You can still build an ADU, but the design must meet the ignition-resistant construction rules in Chapter 7A of the California Building Code, and defensible-space rules apply. The 2025 CAL FIRE maps expanded these zones in the valley, so we check the current map for every parcel.
ADU consultation
Start Your Santa Clarita ADU Project
Describe your lot, the house and the job you want the ADU to do. Once the consultation form arrives, expect a call or email from our team inside 24 hours.
- Design
- Permits
- Construction