Building an ADU in Woodland Hills costs between $150,000 and $350,000 for most projects in 2026. Garage conversions land near the low end. Detached new construction on a hillside lot with fire zone requirements pushes past $350,000. The spread is driven by terrain, LADBS permit track, VHFHSZ status, and whether you're converting an existing structure or building from scratch.
Woodland Hills sits in the western San Fernando Valley (ZIP codes 91364, 91367, 91371). It's an LA County property under LADBS jurisdiction, not Ventura County. That matters for your costs, timeline, and permit process. Everything here is Woodland Hills-specific.
We serve Woodland Hills from our base in Simi Valley, about 20 minutes east on the 101. Safeway Construction has been building ADUs throughout the San Fernando Valley and Ventura County for over 20 years. License #1066117. 5.0 stars on Google.
Before you call anyone, get a free AI-powered estimate at SafewayQuickQuote.com. Enter your ADU type, lot size, and finish preferences. You'll have a real cost range in about 2 minutes. No contractor visit, no sales call required.
ADU Types and What They Cost in Woodland Hills
Not all ADUs are the same project. Cost scales directly with how much structure you're adding, what the site requires, and how independent the unit needs to be.
| ADU Type | Cost Range | Typical Size |
|---|---|---|
| Junior ADU (JADU) | $80,000 – $120,000 | 350–500 sq ft |
| Garage conversion | $120,000 – $175,000 | 400–600 sq ft |
| Attached ADU | $175,000 – $260,000 | 500–700 sq ft |
| Detached ADU (standard lot) | $200,000 – $310,000 | 400–800 sq ft |
| Detached ADU (hillside/premium) | $280,000 – $400,000+ | 500–850 sq ft |
Junior ADU (JADU): $80,000 – $120,000
A Junior ADU is carved out of your existing home (typically a converted bedroom, attached garage section, or ground-floor suite) and capped at 500 sq ft. It shares plumbing systems with the main house but requires a separate entrance and a small efficiency kitchen. JADUs are the lowest-cost ADU type because you're working within the existing building envelope.
On a straight bedroom conversion with existing plumbing nearby, costs land between $80,000 and $100,000. If you're adding a new bath, budget $100,000–$120,000.
Garage Conversion: $120,000 – $175,000
Converting an attached or detached garage to a livable ADU is one of the most popular projects in Woodland Hills. The existing foundation and structure reduce costs compared to new construction, but the scope is more involved than most homeowners expect.
A Woodland Hills garage conversion includes: insulation to current Title 24 energy standards, drywall, flooring, a full kitchen, bathroom, water heater, mini-split HVAC, window additions to meet egress and natural light requirements, and a separate electrical panel or sub-panel. Many garages in the 1960s–1980s housing stock still have 100-amp service feeds. A sub-panel upgrade adds $1,500–$4,000. Fire zone exterior requirements add $8,000–$18,000 if your property is in a VHFHSZ.
Detached ADU — Standard: $200,000 – $310,000
A detached ADU is a freestanding structure on your lot with its own foundation, framing, roof, mechanical systems, and utility connections. In Woodland Hills, most detached ADUs run 400–800 sq ft.
This is the highest-demand ADU type for rental purposes because it's fully independent. Renters in the Warner Center and El Camino neighborhoods pay a premium for detached units, and the rental income potential ($2,000–$2,800/month for a 600 sq ft unit) is strong. Utility connections run $8,000–$22,000 depending on distance from the main line.
Detached ADU — Hillside/Premium: $280,000 – $400,000+
Properties north of Ventura Boulevard (Braemar Ranch, Mulholland Park, Topanga Canyon corridor) sit on terrain that changes the math significantly. Sloped lots require engineered foundations, often caissons at $1,500–$2,500 each (typically 4–8 per structure). Add fire zone material requirements ($8,000–$18,000) and premium finishes for a north-side property trading at $1.5M–$4M, and projects routinely run $280,000–$400,000.
What Drives ADU Cost in Woodland Hills
Terrain and Foundation. South of Ventura Boulevard (Warner Center, El Camino, Girard), lots are relatively flat with standard slab foundations. North of Ventura, caissons, stepped footings, and retaining walls add $15,000–$35,000 to foundation costs.
Fire Hazard Zone Requirements. Properties along Topanga Canyon Boulevard, north of Mulholland Drive, and in the northern hills sit in a Very High Fire Hazard Severity Zone (VHFHSZ). State law requires ignition-resistant construction: Class A roofing, dual-pane tempered windows, ember-resistant vents, and fire-resistive exterior cladding. Add $8,000–$18,000 to exterior costs.
Utility Connections. Every ADU needs sewer, water, and usually gas connections. A simple lateral runs $5,000–$10,000. Trenching through existing hardscape adds $4,000–$12,000. New water service meters cost $2,500–$5,000 through LADWP.
Pre-1980 Home Upgrades. Most Woodland Hills homes were built 1958–1980. Common required upgrades before LADBS signs off: electrical panel replacement ($2,000–$4,500), main sewer lateral lining or replacement ($4,000–$12,000), and gas service upgrade ($1,500–$3,500). We build a 10–12% contingency into every Woodland Hills ADU estimate.
Per-Component Cost Breakdown
Here's how a typical Woodland Hills detached ADU breaks down at the component level. Ranges are for a 500–700 sq ft detached unit on a standard flat-to-moderate-slope lot.
| Component | Cost Range |
|---|---|
| Architectural design and drawings | $5,000 – $16,000 |
| Structural engineering (LADBS-stamped) | $2,500 – $7,500 |
| LADBS permits and plan check | $3,000 – $8,500 |
| LAUSD school developer fee ($4.79/sq ft) | $2,400 – $3,800 |
| Site survey and soils report | $1,500 – $4,500 |
| Grading and site prep | $4,000 – $18,000 |
| Foundation (slab or engineered) | $10,000 – $35,000 |
| Framing (walls, roof, structural) | $18,000 – $42,000 |
| Fire zone exterior materials (if VHFHSZ) | $8,000 – $18,000 |
| Roofing | $5,000 – $14,000 |
| Exterior finish (stucco, siding, windows, doors) | $9,000 – $22,000 |
| Plumbing (rough-in, finish, connections) | $10,000 – $26,000 |
| Electrical (panel, wiring, sub-panel, fixtures) | $8,000 – $18,000 |
| HVAC (mini-split or central, Title 24) | $4,500 – $10,000 |
| Insulation and drywall | $5,000 – $11,000 |
| Kitchen (cabinets, countertops, appliances) | $8,000 – $28,000 |
| Bathroom (tile, fixtures, vanity, glass) | $7,000 – $20,000 |
| Flooring (LVP, tile, or hardwood) | $4,000 – $12,000 |
| Interior finish (trim, doors, paint, hardware) | $4,500 – $10,000 |
| Utility connections (sewer, water, gas) | $8,000 – $22,000 |
| Contingency (10–12%) | $18,000 – $36,000 |
A fully completed 600 sq ft detached ADU in the El Camino or Warner Center sub-neighborhoods (flat lot, standard finishes, no fire zone complications) totals roughly $215,000–$255,000 all-in including permits, fees, and connections.
LA County ADU Permits — Timeline and Fees
Woodland Hills ADU permits go through LADBS, not a Ventura County jurisdiction like Simi Valley or Thousand Oaks. California ADU law (AB 68, AB 881, SB 13) requires LADBS to approve code-compliant ADUs by ministerial review: no discretionary conditions, no neighborhood input.
Standard plan check timeline: Custom-designed ADUs go through standard plan check: 4–8 weeks for first review in 2026. One round of corrections and resubmittal can add 3–4 weeks.
Pre-approved standard plans — faster track: LADBS maintains 20+ pre-approved ADU designs. Permits can issue in 21–30 days. Pre-approved plan sets cost $1,500–$3,500, versus $5,000–$16,000 for full custom design.
LADBS permit fees: Total permit fees for a Woodland Hills ADU run $3,000–$8,500. This is higher than Ventura County jurisdictions ($1,200–$3,500 for comparable ADU permits).
Total permit and fee package: Budget $6,000–$15,000 for permits, plan check, LAUSD school fees ($4.79/sq ft), and site survey.
| ADU Type | Design + Permits | Construction | Total Timeline |
|---|---|---|---|
| JADU (conversion) | 6–10 weeks | 10–16 weeks | 4–6 months |
| Garage conversion | 8–12 weeks | 12–18 weeks | 5–8 months |
| Attached ADU | 10–16 weeks | 16–24 weeks | 6–10 months |
| Detached ADU (standard) | 10–16 weeks | 18–26 weeks | 7–10 months |
| Detached ADU (hillside/fire zone) | 12–20 weeks | 22–32 weeks | 8–14 months |
ADU Rental Income in Woodland Hills
Woodland Hills is one of the stronger rental submarkets in the western San Fernando Valley. Proximity to Warner Center, Topanga State Park, and the 101 corridor creates consistent renter demand.
| ADU Type | Monthly Rent | Annual Gross |
|---|---|---|
| JADU (studio, 350–500 sq ft) | $1,800 – $2,200 | $21,600 – $26,400 |
| Garage conversion (1-bed) | $2,000 – $2,600 | $24,000 – $31,200 |
| Attached ADU (1-bed) | $2,200 – $2,900 | $26,400 – $34,800 |
| Detached ADU (1-bed) | $2,400 – $3,200 | $28,800 – $38,400 |
ROI Analysis
A 600 sq ft detached ADU costing $240,000 all-in, renting for $2,600/month:
- Annual gross rental income: $31,200
- Net after taxes, insurance, maintenance, vacancy: ~$19,500–$22,000/year
- Property value added: $180,000–$280,000
- Combined return: rental income + property appreciation covers build cost within 7–9 years
Woodland Hills homes with permitted ADUs trade at a premium. Buyers in the 91364 and 91367 ZIP codes recognize rental income potential and pay for it.
How to Budget for Your Woodland Hills ADU
Step 1: Identify your ADU type. Garage conversion, detached new build, attached addition, or JADU. Your starting point defines 60–70% of your cost.
Step 2: Check your fire zone status on the LADBS GeoHub fire hazard map. If you're in a VHFHSZ, add $8,000–$18,000 to your exterior estimate.
Step 3: Evaluate your terrain. Flat lot south of Ventura Boulevard? Standard foundation. North-side with slope? Get a soils report early ($1,500–$3,000).
Step 4: Get a ballpark at SafewayQuickQuote.com. Enter your ADU type, square footage, and lot conditions. Real cost range in 2 minutes.
Step 5: Plan for pre-1980 surprises. Budget a 10–12% contingency beyond the ADU construction estimate.
Step 6: Consider the pre-approved plan track. For standard footprints, LADBS pre-approved plans cut design costs by 60–70% and reduce plan check time from 4–8 weeks to 21–30 days.
Financing Options
| Option | Best For | Notes |
|---|---|---|
| HELOC | Homeowners with equity | Variable rate; draw as you go |
| Cash-out refinance | Rate environment permits | Converts equity to fixed-rate financing |
| Construction loan | Large detached builds | Short-term; converts to mortgage at completion |
| CalHFA ADU Grant | Income-qualifying homeowners | Up to $40,000 for pre-development costs |
| Personal savings | JADU / smaller conversions | Avoids interest; works for lower-cost types |
Woodland Hills Neighborhood ADU Cost Guide
El Camino / Girard (South of Ventura Blvd)
Flat lots, 1960s–1970s homes. Standard foundations apply. Most homes already have 200-amp panels from prior updates. A 600 sq ft detached ADU here runs $195,000–$270,000. Lower fire zone exposure than north-side properties.
Warner Center Area (Southwest)
Mix of 1970s–1980s construction, relatively flat terrain. Some properties fall within HOA-adjacent communities. Verify CC&Rs before planning. ADU costs: $175,000–$250,000 for a detached unit.
Topanga Canyon Corridor (Northwest)
Many properties are in VHFHSZ territory. Hillside and canyon terrain adds foundation complexity. Add $8,000–$18,000 for fire zone materials, $10,000–$25,000 for engineered foundation on sloped lots. Detached ADU range: $200,000–$280,000+.
Braemar Ranch / Mulholland Park (Northern Hills)
Premium homes, steep terrain, nearly all VHFHSZ. Caisson foundations, hillside drainage, and retaining walls are standard. HOA architectural review adds 30–60 days. Detached ADU range: $260,000–$400,000+. The higher home values ($1.5M–$4M) support the investment.
Why Homeowners Choose Safeway Construction
We're based in Simi Valley, 20 minutes from Woodland Hills via the 101. We work in both jurisdictions regularly: Ventura County permit offices and LADBS. Most Ventura County contractors don't know LADBS's digital submission requirements or fire zone compliance checkpoints. We do.
- We handle the full LADBS submission: drawings, structural engineering coordination, plan check tracking, and correction responses
- We evaluate pre-approved plan eligibility before recommending custom design — saving $5,000–$10,000 on design fees
- We identify fire zone and terrain factors during the site visit, before any money is spent on design
- Every Woodland Hills proposal includes a fixed scope, itemized costs, and a payment schedule
Our Google rating is 5.0 stars across 17+ verified reviews. Licensed (#1066117), fully bonded, and insured. Over 20 years serving Ventura County and the western San Fernando Valley.
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Frequently Asked Questions
How much does an ADU cost in Woodland Hills in 2026?
Most Woodland Hills ADU projects fall between $150,000 and $350,000. Garage conversions and JADUs land $80,000–$175,000. Standard detached builds run $200,000–$310,000. Hillside/fire zone detached ADUs run $280,000–$400,000+.
How long does it take to build an ADU in Woodland Hills?
Plan for 7–10 months for a detached ADU on a standard lot, and 8–14 months on a hillside or fire zone property. Garage conversions run 4–8 months. LADBS plan check takes 4–8 weeks for custom designs, or 21–30 days with pre-approved plans.
What are the LADBS permit fees for a Woodland Hills ADU?
LADBS building permits, plan check, electrical, and plumbing permits total $3,000–$8,500. Add LAUSD school fees ($4.79/sq ft) and a site survey. Budget $6,000–$15,000 total — higher than Ventura County ($1,200–$3,500).
Do I need HOA approval for an ADU in Woodland Hills?
Some sub-neighborhoods (Braemar Ranch, Mulholland Park) have active HOAs with architectural review. Review typically takes 30–60 days and runs concurrently with LADBS plan check. California law limits HOA ability to block ADUs but allows design standard enforcement.
Is a garage conversion cheaper than building a new ADU?
Yes. Garage conversions use an existing foundation and structure, removing $20,000–$50,000 of costs. A conversion runs $120,000–$175,000 versus $200,000–$310,000 for a detached new build. The tradeoff is size (most garages convert to 400–450 sq ft) and privacy.
What's the difference between a JADU and a standard ADU?
A Junior ADU is carved out of the existing residence, capped at 500 sq ft, and shares plumbing infrastructure. A standard ADU has its own full kitchen, bathroom, and can have separate utility meters. JADUs cost less ($80,000–$120,000) but rent for slightly less due to the shared-wall setup.
Related Woodland Hills Guides
- Woodland Hills ADU Guide: Permits, Zoning & LADBS Process (2026)
- Kitchen Remodel Cost in Woodland Hills (2026)
- Bathroom Remodel Cost in Woodland Hills (2026)
- Room Addition Cost in Woodland Hills (2026)
- Woodland Hills Full Remodeling Guide (2026)
- ADU Cost in Calabasas (2026)
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