ADU collection / Garage 400
400 sq ft · Original design concept
Garage 400
A familiar footprint. A completely new way to live. Convert an existing garage into a private home with a kitchen and bath.
Starting at $100,000
Studio or one bedroom
Explore your options
Concept floor areaStudio or one bedroom
Layouts adapted to your property3–5 months
Construction after permits
Step inside
A closer look at Garage 400.
Original design concept renderings. Finishes and room arrangements are developed for your selected plan.
Compare the arrangement
Two ways to use your space.
Early space-planning diagrams show room relationships, not approved floor plans. Doorways, closets, wall thicknesses, circulation and dimensions are developed in your architectural drawings. Exterior and interior renderings illustrate the design direction.
Make it yours
Explore a layout. Build your estimate.
Layout concepts are subject to site-specific design and approval. Illustrations are not permit drawings.
Illustrative kitchen finish · final selections confirmed during design.
Your home, your priorities
Start with the space you need.
We develop your preferred layout around the property, the way you live, and the finishes you choose. Your written proposal confirms dimensions, specifications and pricing before construction.
Designed for everyday living
- A dedicated kitchen and private bathroom
- Natural light and a connection to the outdoors
- Practical storage and efficient circulation
- Materials and finishes selected with your team
Understand your starting price
$100,000 is a starting estimate for this model. Site work, utility connections, city fees, selected finishes and any changes to scope affect the final proposal.
Design and permitting time is separate from the construction estimate. Existing garage condition and structural work are evaluated during the property review.
Good questions about the Garage 400.
Does my garage qualify for the Garage 400?
Most attached and detached garages with a sound slab, walls and roof can become an ADU. The condition of the existing structure and any structural work it needs are evaluated during the property review and reflected in your written proposal. California law does not allow cities to require replacement parking when a garage is converted.
Will I need an electrical panel upgrade?
Sometimes. A kitchen and bathroom add load to your existing panel, so we check it during the property review. When a 100 to 200 amp upgrade is needed, it typically costs $4,000 to $8,000 and is listed separately in your proposal.
How long does a Garage 400 take?
Construction takes about 3–5 months after permits are issued. Design, engineering and plan check come before that, and most ADU projects run six months to a year from the first meeting to move-in.
Does the starting price include design and permit fees?
No. The starting estimate is for construction only. Design and permit fees are separate and are itemized in your written proposal. Design and permitting time also comes before the construction timeline begins.
Can I keep part of the garage for storage?
No. The Garage 400 uses the entire garage. The whole structure becomes the living unit, so there is no space left over for storage, and storage would need to be planned elsewhere on the property.
Take the next step
Let’s talk about your Garage 400.
Share your property location, goals and preferred model with Green Design and Build.
Request a model consultationIllustrative design concept, not a completed project or permit-ready plan. October 2026 starting estimate for Los Angeles and surrounding Southern California service areas. Final design and pricing follow a property review.
Request your model consultation
Your selected model, finishes and estimate will be included with your inquiry.