ADU Builders & Home Addition Contractors in Santa Clarita, CA
Santa Clarita runs its own Planning and Building & Safety review, protects native oaks, and applies wildland-urban interface rules in fire hazard zones.
Building ADUs and additions in Santa Clarita
Quick answer: Santa Clarita reviews ADUs and additions itself: the Planning Division clears the project under the city's Unified Development Code, then Building & Safety reviews plans, issues permits and inspects. The city's ADU standards allow a detached ADU up to 800 sq ft with 4-ft side and rear setbacks and no ADU parking requirement. Oak trees and fire hazard zones add reviews on many lots.
Santa Clarita is an incorporated city in Los Angeles County, formed in 1987 from the communities of Saugus, Newhall, Valencia and Canyon Country. For parcels inside city limits, the Community Development Planning Division reviews zoning and entitlements, and the Building & Safety Division handles plan review, permits and inspections. Building & Safety will not review ADU plans until Planning has cleared them.
The city's ADU handout sets the main standards: a detached ADU can be up to 800 sq ft with 4-ft side and rear setbacks and a 16-ft height limit (more near transit), a JADU up to 500 sq ft, each with its own exterior entrance, and no parking requirement for ADUs or JADUs. A lot can have each type of ADU.
Three local reviews come up often. Native oaks are protected, so encroaching on or removing an oak needs an Oak Tree Permit, and oak locations belong on the site plan. Sloped lots go through Hillside Development Review. And construction in a Fire Hazard Zone must meet the California Wildland-Urban Interface Code, with LA County Fire Prevention approval for some additions.
Santa Clarita permitting — city Planning, then Building & Safety
For a parcel inside city limits, start with the Planning Division, which reviews entitlements under the Unified Development Code (Title 17 of the Santa Clarita Municipal Code). Its clearance is required before Building & Safety will review ADU plans. Over-the-counter planning approvals commonly cover residential additions and ADUs, while oak tree and hillside reviews are separate permit classes.
Nearby unincorporated communities, such as Stevenson Ranch, are planned by LA County Regional Planning, not the city, so confirm the parcel's jurisdiction before design. Depending on scope, Building & Safety may also route a project to City Engineering, Urban Forestry, LA County Fire Prevention, the school district or County public health.
- City of Santa Clarita Planning Division Zoning, entitlements and ADU clearance for parcels inside city limits.
- City of Santa Clarita Building & Safety Plan review, building permits and inspections.
- Santa Clarita ADU FAQs (Planning Division) City ADU and JADU size, setback, height and parking standards for single-family lots.
- Santa Clarita Urban Forestry — Oak Tree Preservation The city's oak tree ordinance and Oak Tree Preservation Guidelines.
- LA County Regional Planning Zoning and planning for unincorporated areas such as Stevenson Ranch.
- California HCD ADU Handbook State-level ADU baseline that every California city and county must permit at minimum.
Local rules, fees, and site conditions change and vary by parcel. Always confirm current requirements with the reviewing department for your address — this page is general information, not legal or code advice.
Site conditions that affect Santa Clarita projects
- Planning Division clearance before Building & Safety reviews ADU plans.
- Oak Tree Permits for encroaching on or removing native oaks, with oak locations shown on the site plan.
- California Wildland-Urban Interface Code requirements for building in a Fire Hazard Zone.
- Hillside Development Review on sloped lots, with the review class set by average cross slope.
- City Engineering review for grading, retaining walls or geotechnical reports where the scope needs it.
- Confirming the parcel is inside city limits rather than unincorporated LA County.
What we build most often in Santa Clarita
Santa Clarita neighborhoods we cover
Neighborhoods listed describe our coverage area, not project addresses.
Budgeting your Santa Clarita ADU or addition
Every number we publish is a preliminary planning range, not a quote. Cost in Santa Clarita moves with unit size, design complexity, site conditions, utility work, jurisdictional requirements, and finish level. Use our cost estimator to build a starting range, then we produce a detailed construction proposal after feasibility and design work is complete.
Santa Clarita ADU questions, answered
Who reviews ADUs and additions in Santa Clarita?+
For parcels inside city limits, the City of Santa Clarita. The Planning Division clears the project under the Unified Development Code, and Building & Safety then reviews plans, issues permits and inspects. Unincorporated communities such as Stevenson Ranch are planned by LA County instead.
How large can a detached ADU be in Santa Clarita?+
The city's ADU handout allows a detached ADU of up to 800 sq ft with 4-ft side and rear setbacks and a 16-ft height limit, higher near transit. A JADU can be up to 500 sq ft, and there is no parking requirement for ADUs or JADUs.
Will an oak tree on my Santa Clarita lot affect an ADU or addition?+
It can. The city protects native oaks, and encroaching into an oak's protected area or removing an oak requires an Oak Tree Permit. Oak locations must be shown on the ADU site plan, and Urban Forestry clearance can be required before a building permit is issued.
Nearby areas we build in
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Everything you need to plan an ADU, garage conversion, or addition on a property in Santa Clarita.