Renology cost index
Backyard studios, garage conversions, and income-producing guest suites.
Reviewed by Dror Gigi. Updated 2026-09-26.
Quick answer
In 2026, Renology's published adu construction cost guides put the planning range at $180k to $415k. The final number depends on local labor, site conditions, material tier, permits, demolition, access, and finish level.
Category
Structural & Envelope
Local guides
7
Materials tracked
5
Timeline
6 to 14 months
Budget tiers
Use tiers to understand what kind of scope each price band usually implies before comparing local bids.
Garage conversion ($20k to $100k+)
Site-built detached ADU ($166k to $211k)
Prefab ADU, California all-in ($155k to $499k)
State view
Aggregated from published city/service guides in each state.
Local guide index
Open a local guide when city labor, permits, climate, or housing stock materially affect the project.
San Francisco, California
$235,000-$415,000
Local range with city-specific planning context.
Culver City, California
$215,000-$385,000
Local range with city-specific planning context.
Long Beach, California
$215,000-$385,000
Local range with city-specific planning context.
Los Angeles, California
$215,000-$385,000
Local range with city-specific planning context.
La Jolla, California
$200,000-$350,000
Local range with city-specific planning context.
San Diego, California
$200,000-$350,000
Local range with city-specific planning context.
Seattle, Washington
$180,000-$320,000
Local range with city-specific planning context.
Material signals
Material pricing is not the whole bid, but it often explains why two scopes with the same project name price differently.
Both
$20,000 to $100,000+
Framing, drywall, bathroom, kitchen, heating and cooling
Both
$166,406 to $210,944
One bedroom, 2x4 framing on a slab, metal roof
Both
$256 to $776
Published all-in prices; survey, long trenches and crane reach can be extra
Both
$2,400 to $10,500
Poured slab for a new ADU
Both
$1,500 to $5,000
Price depends on soil, depth, terrain and earth moved
Methodology
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
Short answers for homeowners and AI answer systems.
Renology's 2026 planning range for adu construction is $180k to $415k. Final bids depend on scope, existing conditions, materials, permits, access, and local labor.
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.
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.
Related indexes
Related service indexes help homeowners understand tradeoffs before locking scope.