ADU Contractor in Santa Clarita
Santa Clarita breaks the usual ADU assumption: most homes here do not have the detached rear garage that makes conversions cheap elsewhere.
What ADUs look like in Santa Clarita
Valencia, Saugus, Canyon Country, Newhall and Stevenson Ranch are predominantly 1970s–2000s master-planned tract housing, where the garage is attached and integral to the house rather than standing alone at the rear. That pushes most Santa Clarita projects toward a new detached unit in the rear yard, or a JADU carved out of the existing house. Lots are often generous enough to take a detached unit comfortably, but three local factors intrude: slope on the hillside tracts, protected oak trees, and an HOA in most of the newer communities.
Expect a new detached unit or a JADU rather than a garage conversion. The rear yard is usually the asset here; the constraint is what sits on it and who reviews it.
Three ways to add an ADU in Santa Clarita
Santa Clarita breaks the assumption most ADU advice is built on. Valencia, Saugus, Canyon Country, Newhall and Stevenson Ranch are largely 1970s to 2000s master-planned tract housing, and the detached rear garage that makes conversions cheap elsewhere mostly is not there.
| Route | Suits a Santa Clarita lot when | The catch |
|---|---|---|
| Detached new build | The realistic route for most homes here, because there is no detached garage to convert. Tract lots are usually regular and flat enough to take one | Solar is required on new construction, and a protected oak anywhere near the footprint changes the siting before it changes anything else |
| Attached garage conversion | You are willing to give up an attached garage and accept a new door and window on an elevation that faces the street or a common area | Attached conversions change the front of the house more visibly than detached ones, and an HOA in the newer tracts will have a view on that |
| Junior ADU inside the house | You want minimal exterior change and have a bedroom with its own access | Capped at 500 square feet and it costs a bedroom — but it is the least contentious option in a tract with active architectural standards |
Because the cheap conversion route usually is not available here, Santa Clarita projects tend to be new detached builds — which makes the siting question, and particularly the oak question, the one to answer first. Detached ADU vs garage conversion covers the comparison where you do have the choice.
What an ADU costs in Santa Clarita
What moves a Santa Clarita project inside our published ranges: Sloped lots need an engineered foundation. Protected oaks can force the unit further from the house and a longer utility run to reach it, which is a quiet but real cost. Chapter 7A fire-zone construction and a 200-amp service upgrade are both common here. And HOA conditions apply in most of the newer communities — we submit the architectural package first so the permit set matches what the association approved, rather than building twice on paper.
| ADU type | Typical all-in budget |
|---|---|
| Garage conversion | $100,000–$200,000 |
| Detached, about 500 sq ft | $180,000–$260,000 |
| Detached, 700–800 sq ft | $225,000–$350,000 |
| Detached, 1,000 sq ft | $300,000–$450,000+ |
These are typical Los Angeles budgeting estimates, not a price list or a quote. Your project can come in lower or higher depending on the house, the scope and the finishes; the only real number is a written proposal after a site visit.
Budgeting ranges, not quotes — see the full ADU cost breakdown.
How the permit process works in Santa Clarita
Santa Clarita reviews differently from most cities: every ADU and JADU goes through the Planning Division before Building & Safety opens plan check, including any oak-tree clearance. Plans, structural calculations and Title 24 forms are filed through the Accela portal, and the city has 15 business days to declare the application complete and 60 days from that point. We confirm city versus county jurisdiction on the parcel first, because parts of the valley are unincorporated Los Angeles County and the rules and the counter both change. Where an HOA applies, its architectural package goes in first so the permit set matches what was approved.
What we check on a Santa Clarita lot first
- City versus county jurisdiction on the parcel
- Zoning, fire zone, slope and protected oaks
- HOA architectural requirements, submitted first
- Whether an 800 sq ft state-standard or a larger city-standard unit is the better route
That site walk is free, and it is deliberately where we tell people if a lot does not work.
How long a Santa Clarita ADU takes, end to end
Santa Clarita reviews differently from most cities, and the difference matters to your schedule. Every ADU and JADU goes through the Planning Division before Building & Safety opens plan check — including any oak-tree clearance. That is sequential, not parallel, so the front end carries more weight here than elsewhere.
| Phase | What happens | Typical |
|---|---|---|
| Feasibility | Site walk, zoning, HOA standards, and identifying any protected oak before a footprint is chosen | 2–4 weeks |
| Design and engineering | Layout, structural calculations, Title 24, solar — sited to avoid oak conflicts rather than to be argued about later | 2–5 weeks |
| Planning Division review | Runs first, including oak-tree clearance where one applies. Building & Safety does not open plan check until this clears | 3–6 weeks |
| Plan check | Plans, structural calculations and Title 24 forms through the Accela portal; 15 business days to confirm completeness | 4–8 weeks |
| Construction and close-out | Build, inspections, utility connections, certificate of occupancy | 3–6 months plus 1–4 weeks |
Add the phases up and a detached unit runs roughly five to ten months from first conversation to keys. Santa Clarita sits toward the middle of that range more often than the ends, because the housing stock is consistent — the variable is almost always the trees and the tract standards rather than the building. How long an ADU takes covers the phases in more detail.
Oak trees, Edison and SCV Water
Santa Clarita has no single municipal utility — electricity is Southern California Edison and water is SCV Water — and it has one constraint most cities in our area do not: a protected oak ordinance that can decide where your ADU goes.
- Protected oaks. Not just the trunk. The protected zone extends around the tree, and work inside it needs clearance through Planning. Establish this before choosing the footprint — moving a design ten feet at feasibility is free; moving it after Planning review is not.
- Edison service capacity and timing. A second dwelling with kitchen, laundry, air conditioning sized for Santa Clarita summers and required solar is real load, and Edison works to its own schedule.
- SCV Water connection. Separate organisation, separate process, run in parallel with everything else.
The oak question is the one that catches people out, and it is entirely answerable on a first site visit. There is no good reason to discover it at Planning review.
Where we build
We build across the Santa Clarita Valley — Valencia, Saugus, Canyon Country, Newhall and Stevenson Ranch. See everything we build in Santa Clarita.
ADU questions Santa Clarita homeowners ask us
Are the rules different in Stevenson Ranch or Castaic?
They can be, because parts of the Santa Clarita Valley are unincorporated Los Angeles County rather than the City of Santa Clarita. Confirming which jurisdiction your parcel sits in is the first thing we check, because it changes both the rules and the counter you file at.
Can I build an ADU on a lot with protected oak trees?
Usually, yes, but the tree drives the siting. Oak clearance is reviewed by Planning before Building & Safety opens plan check, and the protected root zone often decides where the unit can legally sit — which in turn sets how far the utilities have to run.
Do you handle the permits in Santa Clarita, or do I?
We do — design, engineering, submittal and every correction, dealing with the Santa Clarita reviewers directly.
There is an oak in my back yard. Can I still build?
Usually yes, but the tree decides the siting rather than the other way round. Protection extends beyond the trunk to a zone around it, and work inside that zone needs clearance through the Planning Division. On a first site visit we can tell you roughly where the unit can and cannot go, which is far cheaper than finding out after a design exists.
My garage is attached. Is a conversion still worth it?
Sometimes, but it is a different proposition from the detached conversions people read about. You are changing an elevation that is usually visible, which brings HOA standards into play, and you are giving up parking that is harder to replace on a tract lot. For most Santa Clarita homes a detached new build ends up being the better answer, which is the opposite of the advice that applies in Burbank or the older Valley.
Why does Planning come before plan check here?
It is simply how Santa Clarita runs the process — Planning reviews every ADU and JADU, oak clearance included, before Building & Safety opens plan check. The practical consequence is that anything unresolved at the front end holds up everything behind it, so the feasibility work earns its keep more here than in cities where reviews run in parallel.
Will you tell me if my lot is a bad candidate?
Yes, and the site walk is free so that we can. A protected oak sitting exactly where the unit needs to go, tract standards that rule out what you had in mind, an Edison service that needs work on Edison’s timetable — we would rather say so in the first two hours than take a deposit. You get a written proposal within 48 hours, and it either carries a real number or explains why we think you should not proceed.
Next steps
For what the code allows on your lot, see Santa Clarita ADU rules or run the ADU rules calculator. For our scope, process and warranty, see ADU construction, garage conversions and how we run a project. Our garage-to-ADU conversion is photographed at every stage. Green Design and Build is CSLB #1110975, licensed, bonded and insured.