Renology cost index

ADU Construction Cost Index 2026

Backyard studios, garage conversions, and income-producing guest suites.

Planning range

$80k–$400k

Updated 2026-04-18. Use as a benchmark before comparing itemized bids.

Quick answer

In 2026, adu construction projects tracked by Renology typically plan around $80k–$400k. The final number depends on local labor, site conditions, material tier, permits, demolition, access, and finish level.

Category

Structural & Envelope

Local guides

29

Materials tracked

5

Timeline

6 to 14 months

Budget tiers

ADU Construction budget levels

Use tiers to understand what kind of scope each price band usually implies before comparing local bids.

Garage conversion ($80k to $150k)

$80k–$150k

  • - Convert existing 400-600 sqft garage
  • - Insulation, drywall, flooring, kitchenette, bathroom
  • - Reuse existing slab and framing
  • - Permit, electrical upgrade, gas line if needed

Detached ADU ($180k to $300k)

$180k–$300k

  • - New 600-1,000 sqft detached unit
  • - Full kitchen, 1 bedroom, 1 bath, laundry
  • - Stem-wall foundation, framed construction
  • - Utilities run from main house

Premium or 2-bedroom detached ($320k to $550k+)

$320k–$550k

  • - 1,000-1,200 sqft (CA max)
  • - 2 bedrooms, 2 baths, full kitchen, designer finishes
  • - Separate utility meters, dedicated parking
  • - Architectural design, premium millwork and appliances

State view

ADU Construction ranges by state

Aggregated from published city/service guides in each state.

Local guide index

City-level adu construction ranges

Open a local guide when city labor, permits, climate, or housing stock materially affect the project.

Oakland, California

ADU Construction Cost in Oakland (2026)

$235,000-$415,000

Local range with city-specific planning context.

San Francisco, California

ADU Construction Cost in San Francisco (2026)

$235,000-$415,000

Local range with city-specific planning context.

Beverly Hills, California

ADU Construction Cost in Beverly Hills (2026)

$215,000-$385,000

Local range with city-specific planning context.

Calabasas, California

ADU Construction Cost in Calabasas (2026)

$215,000-$385,000

Local range with city-specific planning context.

Culver City, California

ADU Construction Cost in Culver City (2026)

$215,000-$385,000

Local range with city-specific planning context.

Encino, California

ADU Construction Cost in Encino (2026)

$215,000-$385,000

Local range with city-specific planning context.

Glendale, California

ADU Construction Cost in Glendale (2026)

$215,000-$385,000

Local range with city-specific planning context.

Long Beach, California

ADU Construction Cost in Long Beach (2026)

$215,000-$385,000

Local range with city-specific planning context.

Los Angeles, California

ADU Construction Cost in Los Angeles (2026)

$215,000-$385,000

Local range with city-specific planning context.

Malibu, California

ADU Construction Cost in Malibu (2026)

$215,000-$385,000

Local range with city-specific planning context.

Pasadena, California

ADU Construction Cost in Pasadena (2026)

$215,000-$385,000

Local range with city-specific planning context.

Santa Monica, California

ADU Construction Cost in Santa Monica (2026)

$215,000-$385,000

Local range with city-specific planning context.

Sherman Oaks, California

ADU Construction Cost in Sherman Oaks (2026)

$215,000-$385,000

Local range with city-specific planning context.

Anaheim, California

ADU Construction Cost in Anaheim (2026)

$210,000-$380,000

Local range with city-specific planning context.

Huntington Beach, California

ADU Construction Cost in Huntington Beach (2026)

$210,000-$380,000

Local range with city-specific planning context.

Irvine, California

ADU Construction Cost in Irvine (2026)

$210,000-$380,000

Local range with city-specific planning context.

Newport Beach, California

ADU Construction Cost in Newport Beach (2026)

$210,000-$380,000

Local range with city-specific planning context.

Carlsbad, California

ADU Construction Cost in Carlsbad (2026)

$200,000-$350,000

Local range with city-specific planning context.

Del Mar, California

ADU Construction Cost in Del Mar (2026)

$200,000-$350,000

Local range with city-specific planning context.

Encinitas, California

ADU Construction Cost in Encinitas (2026)

$200,000-$350,000

Local range with city-specific planning context.

La Jolla, California

ADU Construction Cost in La Jolla (2026)

$200,000-$350,000

Local range with city-specific planning context.

San Diego, California

ADU Construction Cost in San Diego (2026)

$200,000-$350,000

Local range with city-specific planning context.

Bellevue, Washington

ADU Construction Cost in Bellevue (2026)

$180,000-$320,000

Local range with city-specific planning context.

Issaquah, Washington

ADU Construction Cost in Issaquah (2026)

$180,000-$320,000

Local range with city-specific planning context.

Material signals

Materials that move the budget

Material pricing is not the whole bid, but it often explains why two scopes with the same project name price differently.

Both

Garage conversion (sqft cost)

$200-$320

Cheapest ADU path

Both

Detached stick-built ADU

$300-$500

Most flexibility

Both

Prefab modular ADU

$280-$450

Faster build time

SoCal

Container-based ADU

$220-$380

Modern aesthetic

Both

Site work and utilities

$15,000-$50,000

Trenching, sewer hookup

Methodology

How this cost index is built

This page combines the Renology service guide for adu construction, local city/service guides, material notes, budget tiers, and editorial review. It is designed for early planning and answer extraction, not as a contractor quote.

Compare this page with the full Renology Cost Index and the full ADU Construction guide before requesting bids.

See the Renology Methodology for how sources are reviewed, how ranges are normalized, and where the limits of planning data begin.

Answered for search

ADU Construction cost FAQ

Short answers for homeowners and AI answer systems.

How much does adu construction cost in 2026?

Renology's 2026 planning range for adu construction is $80k–$400k. Final bids depend on scope, existing conditions, materials, permits, access, and local labor.

What changes the price of adu construction most?

The largest pricing swings usually come from demolition, prep work, structural or utility changes, material tier, finish level, waterproofing or weather exposure, permit requirements, and contractor availability.

Are these numbers contractor quotes?

No. The cost index is a planning benchmark, not a fixed quote. Homeowners should compare the index against 2 to 3 itemized bids once the scope is clear.

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