CaliCustomADU

Our services

Every ADU service, under one contract

Design, permitting and construction from a single team — so your backyard home goes from first call to move-in without the finger-pointing between architects, engineers and builders.

Detached ADUs

400–1,200 sq ft standalone backyard homes

The most popular project in California. We site the unit to meet state-mandated 4-foot setbacks, orient windows and doors for light and privacy, and design around your yard's drainage and utility runs. Every detached ADU is engineered for your city's snow, wind and seismic requirements — nothing cookie-cutter.

  • ✓Site feasibility & concept plans
  • ✓Full architectural plan set
  • ✓Title 24 energy calculations
  • ✓Structural & civil engineering
  • ✓Permit submittal & corrections
  • ✓Complete ground-up construction

9–14 months from first call to move-in

Garage Conversions

Turn an unused garage into a legal rental

The fastest, lowest-cost path to a new unit. California law prohibits cities from requiring replacement parking, so your garage can become a studio or 1-bedroom with its own kitchen, bathroom and entrance. We handle the foundation check, new utility separations, insulation, and the complete interior build-out.

  • ✓Garage structural assessment
  • ✓Conversion plan set
  • ✓New electrical panel & metering
  • ✓Plumbing & HVAC design
  • ✓Permit submittal & corrections
  • ✓Full interior build-out

4–7 months from first call to move-in

Attached ADUs

Additions with a private entrance

Ideal for multigenerational living or when your lot is tight. An attached ADU shares a wall with the main house, which lowers construction cost per square foot while giving everyone privacy. We detail the fire separation, sound insulation and separate entry so it feels like its own home.

  • ✓Addition design & plan set
  • ✓Fire separation detailing
  • ✓Structural engineering
  • ✓Title 24 energy calculations
  • ✓Permit submittal & corrections
  • ✓Complete construction

8–13 months from first call to move-in

Junior ADUs (JADUs)

Up to 500 sq ft inside your existing home

Carved from an existing bedroom, den or attached garage, a junior ADU is the most affordable way to add a legal rental. State law lets JADUs share sanitation facilities with the main house, which keeps plumbing costs minimal. Owner-occupancy applies, but many cities waive it for JADUs.

  • ✓Floor plan feasibility review
  • ✓JADU plan set
  • ✓Kitchenette & bath design
  • ✓Exit & egress compliance
  • ✓Permit submittal
  • ✓Interior build-out

3–5 months from first call to move-in

Two-Story ADUs

Maximize small lots with vertical space

When your backyard can't fit a wide footprint, a two-story ADU doubles living space on the same foundation. We design compact stair layouts, upstairs decks and setbacks that clear second-story plane limits common in older California neighborhoods.

  • ✓Height & setback study
  • ✓Two-story plan set
  • ✓Structural & foundation engineering
  • ✓Title 24 energy calculations
  • ✓Permit submittal & corrections
  • ✓Complete construction

10–16 months from first call to move-in

Permits & Plans Only

Already have a builder? We'll get you permitted

If you're managing construction yourself, our in-house architects and drafters produce a complete, city-ready plan set and shepherd it through plan check. We respond to every correction notice until your permit is issued — usually in one or two review cycles.

  • ✓Measured as-built drawings
  • ✓Full architectural plan set
  • ✓Engineering & Title 24
  • ✓City submittal management
  • ✓Unlimited correction responses

6–12 weeks to issued permit

How we work

  1. 01

    Free feasibility check

    We review your lot, zoning, setbacks and utilities, then send a ballpark budget — usually within two business days.

  2. 02

    Design

    Our architects draft a custom plan around how you want to use the unit: rental, family, office or downsizing.

  3. 03

    Permits

    We submit to your city's building department, answer every plan-check comment and pull the permit for you.

  4. 04

    Construction

    One vetted crew, one project manager, one contract. You get a fixed schedule with weekly photo updates.

  5. 05

    Move-in & rent

    Final inspections, certificate of occupancy, and help listing the unit if you're renting it out.

What you can count on

One contract, one team

Design, permitting and construction never get handed off between firms — so nothing falls through the cracks.

Fixed-price proposal

You see the full cost before construction starts. Change orders only happen if you change the plans.

Local permitting expertise

We've submitted ADU plans to dozens of California building departments and know what each one looks for.

Rent-ready finishes

Durable, attractive materials chosen for rental performance — not showroom pricing, not builder-grade bland.

Service questions

Which service is right for my property?

It depends on your lot, budget and goals. A garage conversion is usually the fastest and cheapest; a detached ADU offers the best rental income; a junior ADU is the lowest-cost entry point. Our free feasibility check recommends the best fit for your specific lot.

Do you handle design, permits and construction?

Yes — every service above is delivered in-house by our architects, drafters and construction teams under one contract. You have a single point of contact from first call to final inspection.

What does a project actually cost?

Most California ADUs land between $150k and $420k all-in depending on type, size and site work. Junior ADUs start around $90k. Every feasibility check includes a written ballpark budget before you commit to anything.

Can I use just your permitting service?

Yes. Our Permits & Plans Only service gets your plan set through plan check and to an issued permit, typically in 6–12 weeks, and includes responses to every correction notice.

How do I start?

Request a free feasibility check — tell us your address and what you're hoping to build. We review zoning, setbacks and utilities and come back with a ballpark budget and timeline, no obligation.

Not sure which service fits your lot?

Get a free feasibility check — we'll review your address and recommend the ADU type with the best return.