How much does a detached ADU cost in West Hills in 2026?

A detached ADU of 600 to 1,200 square feet typically runs $250,000 to $500,000 in 2026, or roughly $150 to $450 per square foot. Los Angeles permit and plan check fees add about $5,000 to $14,000, and an LADWP separate meter adds $3,000 to $6,000.

How long does an ADU permit take in West Hills?

Through the LADBS Van Nuys field office, a flatland garage conversion clears plan check in about 4 to 8 weeks, a new detached flatland ADU in 8 to 14 weeks, and a hillside ADU in 12 to 18 weeks. LADBS pre-approved Standard Plans are issuing in 21 to 30 days.

ADU Builder in West Hills, CA

An ADU (accessory dwelling unit) is a fully independent second home — kitchen, bathroom, and its own entrance — built on the same West Hills lot as your existing house. As of August 2026, Los Angeles reviews code-compliant ADUs ministerially: if the plans meet code, LADBS must approve them, with no discretionary hearing and no neighbor veto.

Last updated: August 2026. Three numbers worth having before you start: detached ADUs in Los Angeles run $250,000–$500,000 for 600–1,200 sq ft in 2026, or roughly $150–$450 per square foot depending on type and finish level; City of Los Angeles permit and plan-check fees run about $5,000–$14,000 (LADBS’s own published example for a 1,200 sq ft detached unit is $8,447.62); and an LADWP separate meter adds roughly $3,000–$6,000 when you choose one.

HomeSense Construction & Remodeling is headquartered in West Hills, at 6571 Ponce Ave, and has been building in the San Fernando Valley since 2011 under CA License #1125001. West Hills ADUs are not generic ADUs — nearly the entire community sits in a Very High Fire Hazard Severity Zone (VHFHSZ), which changes materials, clearances, and plan-check scope. That is the part most out-of-area builders get wrong.

What does it cost to build an ADU in West Hills in 2026?

Cost tracks the type of ADU far more than the finishes. A garage conversion reuses an existing slab and walls; a detached new build pays for foundation, framing, roof, and a full set of utility runs.

ADU type	Typical size	2026 all-in range (West Hills)	Plan check to permit
Garage conversion ADU	350–500 sq ft	$120,000–$200,000	4–8 weeks
JADU (inside the main house)	up to 500 sq ft	$90,000–$160,000	4–6 weeks
Attached ADU	500–800 sq ft	$180,000–$320,000	6–12 weeks
Detached ADU, flat lot	600–1,200 sq ft	$250,000–$500,000	8–14 weeks
Detached ADU, hillside lot	600–1,000 sq ft	$320,000–$600,000	12–18 weeks

Two fee items save real money when you plan for them. ADUs at or under 750 sq ft are exempt from local impact fees, and under 500 sq ft they are exempt from school impact fees statewide. And keeping the ADU on the main house’s existing utility service — rather than pulling a separate LADWP meter — avoids the $3,000–$6,000 meter cost, which makes sense for family use and less sense for a long-term rental where you want the tenant billed directly.

How long does an ADU permit take at LADBS for a West Hills property?

West Hills plan check is handled through the LADBS Van Nuys field office. In 2026 the realistic timelines are 4–8 weeks for a flatland garage conversion, 8–14 weeks for a new detached flatland ADU, and 12–18 weeks on a hillside parcel where Baseline Hillside Ordinance grading review stacks on top of the standard checks.

Two 2026 accelerators are worth using. Under AB 1332, every California city must maintain a program of pre-approved ADU plans and review permits for them within 60 days; LADBS’s ADU Standard Plan Program offers pre-approved Plans A and B (1,200 sq ft) and Plan C (800 sq ft), and in practice those permits are issuing in 21–30 days. Separately, all ADU plan reviews must be completed within 60 days or the application is deemed approved. If a standard plan fits your lot, it is the fastest path to a permit in Los Angeles.

What does West Hills’ fire hazard zone designation change about your ADU?

Nearly all of West Hills — particularly the parcels backing the Santa Susana foothills, Chatsworth Reservoir, and Bell Canyon — is mapped as a Very High Fire Hazard Severity Zone. LADBS still approves code-compliant ADUs there by ministerial review, but the build must satisfy 2022 California Building Code Chapter 7A materials and assemblies:

Class A roof assembly — no exceptions in a VHFHSZ.
Ember-resistant vents (listed to ASTM E2886) at every attic and under-floor opening.
Dual-glazed windows with one tempered pane, and exterior doors rated to Chapter 7A.
Ignition-resistant or noncombustible siding, eaves, and soffits — enclosed eaves are the norm.
Defensible space: 100 ft of managed clearance under CAL FIRE / PRC 4291, plus California’s Zone 0 ember-resistant rule requiring the first 5 feet around the structure be kept free of combustible material and plantings.

Practically, Chapter 7A compliance adds roughly 6–10% to the shell cost of a West Hills ADU versus an identical unit in a flatland Valley neighborhood — and skipping it is what gets a set of plans bounced back at plan check. Energy compliance runs alongside it: the 2025 Title 24, Part 6 standards in effect for 2026 permits treat the ADU as its own dwelling in Climate Zone 9, which for most West Hills detached units means a heat-pump HVAC system, a heat-pump water heater, and a solar allocation calculated for the new floor area.

Which ADU type fits your West Hills lot?

West Hills lots are generally generous — a large share of the housing stock is 1960s–1970s tract construction on 7,000–10,000+ sq ft parcels with detached or attached two-car garages and deep rear yards. That mix supports every ADU type:

Garage conversion — the fastest and cheapest path. State law bars cities from requiring you to replace the parking you convert.
JADU — up to 500 sq ft carved out of the existing house, with an efficiency kitchen; can be combined with a detached ADU on the same lot.
Detached new-build — up to 1,200 sq ft, the best rental economics and the highest resale contribution. Setbacks are 4 ft from the side and rear property lines by state law.
Multifamily lots — under SB 1211, eligible multifamily properties can add up to eight detached ADUs (capped at the number of existing units).

If you already have an unpermitted converted garage or back unit — common across West Hills and Canoga Park — AB 2533 creates a legalization pathway for units built before January 1, 2020, judged on health and safety rather than full current-code compliance. We handle those as a distinct scope: inspection first, corrections second, permit last.

How HomeSense builds an ADU in West Hills

Site walk and feasibility (week 1). Setbacks, utility locations, sewer depth, panel capacity, VHFHSZ status, and hillside grading exposure — before anyone draws anything.
Design and engineering (weeks 2–6). Architectural set, Title 24 energy calculations, and structural engineering; or a fitted LADBS Standard Plan when the lot allows.
Plan check and permits (weeks 6–20). Submittal through the Van Nuys LADBS office, correction cycles, and LADWP coordination. We manage every response.
Site work and foundation (weeks 1–4 of construction). Grading, trenching for water, sewer and electrical, and the slab or raised foundation.
Framing, rough-in, inspections. Framing, MEP rough-in, Chapter 7A exterior assemblies, insulation, then drywall.
Finishes and final (last 4–6 weeks). Kitchen, bath, flooring, fixtures, exterior, defensible-space clearance, final inspection, and Certificate of Occupancy.

A typical detached West Hills ADU runs 5–7 months of construction after permits issue, with design and plan check adding 3–5 months ahead of that.

What’s included when HomeSense builds your ADU

Feasibility study, full architectural set, structural engineering, and Title 24 energy compliance
LADBS permit submittal, correction responses, and inspection coordination — start to Certificate of Occupancy
Chapter 7A fire-hardened exterior assemblies and Class A roofing as standard, not an upcharge line item
Utility work: sewer tie-in, water, electrical sub-panel or LADWP separate meter, and gas where used
Complete interior build-out — kitchen, bathroom, flooring, HVAC, and finishes
A fixed written scope and schedule, one point of contact, and workmanship warranty

Why West Hills homeowners hire HomeSense

We are based in West Hills — 6571 Ponce Ave — which means our crews are minutes from the job, not commuting from across the county. We have built in this ZIP code since 2011, we know how the Van Nuys LADBS counter reads a hillside submittal, and we build to Chapter 7A because our own neighborhood requires it.

The California Contractors State License Board advises homeowners to verify a contractor’s license and confirm workers’ compensation coverage before signing any contract. Ours is CA License #1125001, active and verifiable at cslb.ca.gov, and we carry general liability and workers’ compensation on every job.

Frequently asked questions about ADUs in West Hills

Does an ADU increase my property taxes in West Hills?
Only the new construction is reassessed — the existing house keeps its Proposition 13 base year value. You are taxed on the added value of the ADU, not on a fresh valuation of the whole property.

Can I build an ADU on a hillside lot in West Hills?
Yes. Hillside parcels fall under the Baseline Hillside Ordinance, which adds grading limits, haul-route review, and usually a geotechnical report. Plan on 12–18 weeks for plan check rather than 8–14, and a higher foundation cost.

Do I need to add parking for my ADU?
No, in most cases. State law prohibits a parking requirement for an ADU within a half mile walking distance of public transit, and bars cities from requiring replacement parking when a garage is converted.

How much rent does a West Hills ADU bring in?
As of 2026, detached one-bedroom ADUs in the West Valley commonly rent in the $2,200–$3,000 per month range, depending on size, parking, and whether utilities are separately metered.

Can I sell the ADU separately from my house?
Generally no. ADUs cannot be sold apart from the primary residence except through a narrow qualified-nonprofit pathway. They add value as part of the property, and they can be rented independently.

How soon can you start?
Feasibility walks are usually scheduled within a week. Call (818) 300-3422 or message us on WhatsApp at (818) 266-1292 to get on the calendar.

Start your West Hills ADU

Tell us the lot and what you want the unit to do — rental income, family housing, or a home office — and we will tell you what it will actually cost and how long it will take, in writing. Call (818) 300-3422, WhatsApp (818) 266-1292, or email homesense2000@gmail.com. HomeSense Construction & Remodeling, 6571 Ponce Ave, West Hills, CA 91307. CA Lic #1125001.