“Lior is very personable and has many decades of construction experience. We appreciated his sincere evaluation of our project.”
Ann AnterasianHouzz · April 2019
ADU construction · Hidden Hills, CA
Hidden Hills ADUs to
Estate and Equestrian Standard
City permits plus HHCA architectural review, multi-acre lots with horses on them, and guest houses that must look like they belong — that's the Hidden Hills ADU brief. CSLB #972213.
Free Estimate · No Obligation
Get a Free Hidden Hills ADU Estimate
Tell us about your project — we'll respond within 24 hours.
CSLB LicensedLicense #972213
5.0 on Houzz17 verified reviews
Family-OwnedLicensed since 2010
24-Hour ResponseFree in-home estimate
City + HHCAArchitectural review · in-house
Why Hillstar
Why Hidden Hills Estates Build With Hillstar
Behind these gates an ADU is a second residence on a working equestrian property — reviewed twice and expected to be excellent.
City + HHCA, One Package
The City of Hidden Hills issues permits; the Community Association's architectural committee reviews design. Both submittals leave our office together.
Equestrian-Lot Siting
Barns, corrals, and trail access shape where a unit belongs. We site around the property's working layout, not over it.
Septic & Utility Verification
Some properties run private septic; capacity and layout get verified at feasibility before drawings assume anything.
Fire-Zone Construction Standard
Santa Monica Mountains foothills put much of the city in mapped fire-severity zones — ignition-resistant assemblies are our default here.
Estate-Match Design
Roof forms, materials, and massing chosen to pass HHCA review and to belong on the street.
Full-Scope Delivery
One crew and one contract from feasibility through the city's final inspection.
Our process
The Hidden Hills Build Path
Dual review, run in parallel; construction run quiet.
1
Feasibility on the Property
Siting, septic where present, utilities, fire-zone status, and HHCA expectations assessed together.
2
Design & Dual Filing
City permit package and HHCA submission prepared simultaneously and tracked to approval.
3
Construction
Our crew builds to estate standard, respecting the community's private-street rules throughout.
4
Delivery
Final inspections, punch list, and a written workmanship warranty.
Local conditions
Permits, Lots & What's Specific to Hidden Hills
Hidden Hills is its own incorporated city, and it's unlike anything else in the region — gated, private-street, equestrian-zoned. State ADU law applies; what changes here is the community-association layer on top of the city, and the rural-feel infrastructure that doesn't match a suburban tract.
Permit jurisdiction
City of Hidden Hills issues every Hidden Hills ADU permit. LADBS does not. The LA City Standard ADU Plan Program is not accepted; designs are drawn for the Hidden Hills code path. Inside the gates, the Hidden Hills Community Association (HHCA) Architectural Review Committee provides a parallel design-review track — visible exterior changes typically route through both the city and HHCA, and we file both submissions together.
Lot & property patterns
Hidden Hills runs to large equestrian-zoned parcels — multi-acre lots, no sidewalks, private streets, equine keeping. Some properties carry private septic systems, and lot-specific utility configurations differ from the city-grid services typical of the Valley flats. ADU siting has to respect equestrian setbacks (barns, corrals, trails), septic envelope where applicable, and the long driveway/access patterns the lots are built around.
Design overlays you'll see here
HHCA architectural-review covenants are the dominant design layer here — exterior materials, roof form, fenestration pattern, fence and gate detail, and view-impact criteria all go through the HHCA committee on top of the city plan check. Hidden Hills sits in the Santa Monica Mountains foothills, and a large share of the city is inside California Fire Hazard Severity Zones, which trigger Chapter 7A WUI compliance (Class A roof, ignition-resistant siding, ember-resistant vents) and defensible-space planning where they apply. Mature oaks are common across the hillside lots; tree-protection review is routed at design.
Design examples
ADU Design Examples
Examples of ADU styles and layouts.
Reviews
Homeowners on Working With Hillstar
Verified Houzz reviews from Hillstar Construction clients.
“Lior is a fantastic general contractor. He has tremendous work ethic and strong attention to detail.”
J. GlaserHouzz · June 2017
“Hillstar's crew was courteous, prompt, and worked hard to make every detail exactly what we wanted.”
Hillstar ClientHouzz · Verified
5.0 · 17 verified reviews on Houzz
FAQ
Hidden Hills ADU — FAQ
Dual approvals, equestrian properties, septic checks, fire standards, and guest-house budgets.
How do approvals work for a Hidden Hills ADU?
Two tracks: the City of Hidden Hills issues the building permit, and the Hidden Hills Community Association's architectural committee reviews the design — materials, roof form, siting, and how the unit reads from the street. State law guarantees the ADU right; the two reviews shape its execution. We file both at once.
Can the ADU coexist with our horses?
That's the point of siting it well. Multi-acre equestrian parcels leave room to place a unit away from barns, corrals, and trail routes while keeping utility runs sensible. The feasibility walk maps the property's working layout first, then positions the unit inside it.
What if the property is on septic?
Then the system's capacity and field layout get verified before design — a second dwelling adds real load, and the answer determines fixture counts or a system upgrade. It's a known variable here, and we resolve it at feasibility rather than at plan check.
What fire construction applies?
Most of Hidden Hills sits in the Santa Monica Mountains foothill fire zones, so new construction carries ignition-resistant requirements: Class A roof assemblies, ember-resistant vents, protected eaves, and defensible-space compliance. We treat that as the baseline spec for these lots.
What does a guest house here cost?
It's a custom second residence, so design decides. The commitments that don't vary: a full itemized written quote after feasibility, HHCA and city costs shown as their own lines, and written approval before any change is built.
Also serving Hidden Hills
Nearby ADU neighborhoods
Plan a Guest House Behind the Gates
Free on-site feasibility — siting, approvals, systems, and a written plan.