Where every dollar actually goes.
Twenty-eight line items, four categories. Compiled from real Los Angeles County ADU and residential construction projects.
Move the slider to see how the budget redistributes across the four buckets.
- Soft costs11%
- $36,310
- 6.2–16.1% range
- Site work7%
- $23,284
- 2.4–11.9% range
- Hard construction72%
- $232,841
- 55.0–88.0% range
- Contingency10%
- $32,565
- 8.0–12.0% range
Export the current breakdown — a CSV for spreadsheets or a print-ready PDF for lender packages and contractor walkthroughs.
Soft costs
$36,310 · 11%
Everything before a single nail is driven: design, engineering, Title 24, surveys, and city plan-check fees. The smallest bucket — but the one that decides whether the rest goes smoothly.
| Line item | Range % | Dollars at current budget |
|---|---|---|
Architectural design Higher with custom millwork | $13,813 | |
Structural + MEP engineering | $5,850 | |
Title 24 energy compliance | $1,950 | |
Geotech / soils (hillside) Required on slopes | $2,925 | |
Survey + civil | $2,275 | |
City plan check + permit | $7,475 | |
School district fees Waived under 500 sq ft | $1,950 |
Site work
$23,284 · 7%
The silent budget killer. Demolition, grading, sewer lateral, panel upgrade, and trenching for new utility runs. Two identical floor plans on different lots routinely diverge by $30K right here.
| Line item | Range % | Dollars at current budget |
|---|---|---|
Demolition + clearing | $3,900 | |
Grading + drainage | $5,200 | |
Utility trenching | $6,175 | |
Sewer lateral verification / replace Replace if undersized | $4,063 | |
Electrical panel upgrade If existing < 200A | $3,900 |
Hard construction
$232,841 · 72%
The bulk of the build — foundation, framing, MEP, drywall, finishes, fixtures, appliances. The only bucket where owner choices (cabinetry tier, appliance package) move the number meaningfully.
| Line item | Range % | Dollars at current budget |
|---|---|---|
Foundation + slab | $22,750 | |
Framing + sheathing | $34,125 | |
Roofing + envelope | $17,063 | |
Windows + exterior doors | $14,625 | |
Insulation + drywall | $16,250 | |
Plumbing rough + fixtures | $20,313 | |
Electrical rough + finish | $17,875 | |
HVAC (heat pump) | $12,188 | |
Required new construction | $10,563 | |
Cabinetry + millwork Biggest finish swing | $19,500 | |
Countertops + tile | $11,375 | |
Flooring | $11,375 | |
Interior paint + finish carpentry | $10,563 | |
Appliances | $8,125 | |
Landscape restoration | $5,688 |
Contingency
$32,565 · 10%
Reserved for the surprises that come out of the existing structure: termite damage, undocumented additions, failed laterals. We hold 10% on flat-lot new construction and 15% on conversions.
| Line item | Range % | Dollars at current budget |
|---|---|---|
Construction contingency 10% on flat lots, 15% on conversions | $32,500 |
FAQ
Frequently asked questions
Six questions we field every week from LA homeowners pricing an ADU.
Why is your cost shown as a range instead of one number?
Lot conditions, finish tier, and the state of your existing utilities meaningfully shift each line item. We publish ranges so the math stays honest — your fixed-fee feasibility document hardens it into one number specific to your address.Does this breakdown include the city permit and impact fees?
Yes. Plan check, LADBS permit, school district fees (waived under 500 sq ft) and Title 24 compliance are all in the soft-costs bucket. Utility connection fees from LADWP are also included where applicable.What's not included in the percentages above?
Land cost, financing interest, property taxes during construction, furniture, and any major hardscape or pool relocation outside the ADU footprint. Sewer lateral replacement is shown as a conditional line item because roughly one in three LA lots needs it.How accurate is the contingency range?
We hold 10% on flat lots with new construction and 15% on garage conversions or hillside builds. Across our last 50 projects, 78% closed inside contingency and the rest were within 4% of it.Can I lower the cost by acting as my own GC?
You can save 8–14% on paper, but you assume schedule risk, lien risk, and warranty exposure. For most homeowners the savings disappear inside the first change order. We're happy to walk you through the tradeoff on a feasibility call.Do you offer financing on the build itself?
We don't lend, but we work with three LA-based credit unions and two private construction lenders who underwrite ADU-specific draws. We'll introduce you once feasibility is signed.What does a garage conversion really cost in Los Angeles in 2026?
A permit-clean 400 sq ft LA garage conversion lands at $145K–$195K all-in for 2026: $11K–$16K design + Title 24, $5K–$9K permits and fees, $48K–$66K finishes, and a real 10–12% contingency on top. Anything under $130K either skips legalization steps or hides scope. We publish the full line-item breakdown so you can stress-test any quote.How much does an 800 sq ft detached ADU cost in San Jose or the South Bay?
An 800 sq ft detached 1-BR ADU in San Jose runs $365K–$430K all-in in 2026; Sunnyvale and Cupertino are $35K–$60K higher. Permits issue ministerially in 10–14 weeks in San Jose. The South Bay premium over LA is roughly $75K–$110K on the same product, driven mostly by labor wages.Why is Santa Monica or Manhattan Beach so much more expensive than Long Beach?
Coastal cities carry three cost layers eastern LA basin cities don't: Coastal Commission appeal jurisdiction (adds 6–10 weeks), Architectural Review Board materials and massing review on units >700 sq ft, and a 12–18% labor wage premium. A turnkey 800 sq ft detached ADU in Santa Monica runs $385K–$465K vs $315K–$380K in Torrance and $295K–$370K in Long Beach.Where in LA County do ADUs pencil best in 2026?
Highest gross ROI: Inglewood, Hawthorne and South LA on cost-per-rent. Highest absolute rent: Santa Monica, Manhattan Beach and Beverly Hills. Best mid-term rental yields: Burbank and Culver City for studio talent. Best ministerial speed: Long Beach and Burbank — both finish 4–7 weeks ahead of LA City on equivalent projects.What's the real cost difference between Oakland, Berkeley and San Francisco?
An 800 sq ft detached ADU in 2026: Oakland $355K–$425K, Berkeley $400K–$485K (the energy-code premium adds $14K–$22K), San Francisco $475K–$580K. SF runs $100K–$160K above Oakland on the same product — labor, SFPUC connection fees, and longer end-to-end timelines compound the gap.What's the existing-structure scope I should budget on a pre-1978 home?
Plan on three baseline existing-structure costs on most pre-1978 California homes: 200A panel upgrade ($4.5K–$8K plus utility coordination), sewer lateral inspection ($400) with conditional replacement ($8K–$18K), and Title 24 envelope coordination on attached or conversion ADUs. In Oakland, SF and Berkeley, also budget soft-story exposure ($18K–$55K) and flush it out in feasibility — not framing.