ADU STACK

Bay Area ADUs

Build together. Save smarter.

A small group of homeowners. Smart, space-efficient floor plans. One experienced team guiding every step.

From $325,000 before city fees, utilities, and solar

Join the Founding Cohort Check Your Lot

Free to join No deposit 40+ Bay Area projects delivered

Illustrative rendering of a single-story backyard ADU with cedar and dark panel siding, a standing-seam metal roof, and large glass doors
Illustrative rendering of a single-story backyard ADU.

Why ADUStack

Built around your life and your budget.

More room for you, your parents, or your grown kids, without the project taking over your life.

  • One team, one point of contact.Your life is already full. One team coordinates the design, permits, utilities, materials, and construction, and keeps you updated from first question to move-in.
  • Know your price before you commit.Our starting prices are published. Before you commit, you get every cost for your property in writing, including estimated city fees, utility connections, and solar.
  • Built to cost less, together.Homes in a cohort share the same floor plans and buy materials together, so those costs are spread across every home. We'll publish the savings once the first cohort's bids are in. Until then, they're a goal, not a guarantee.

Pricing

What it costs.

Founding Cohort starting prices, published here. They don't go up as more homes join the cohort.

Concept rendering of the 749 sq ft ADU: a bedroom with glass doors at each end and a central living room and kitchen behind tall glass doors, with dark panel and cedar siding under a standing-seam metal roof
Concept rendering
Floor plan of the 749 sq ft ADU: two bedrooms with their own bathrooms and closets on either side of an open living room and kitchen with an island, and a 4-foot porch along the full front
Floor plan

749 sq ft

2 bedrooms · 2 bathrooms · 38 × 20 ft

From $325,000

Under 750 sq ft, so California law exempts it from city impact fees.

Concept rendering of the 1,199 sq ft ADU: gray panel and wood slat siding, a standing-seam metal roof with solar panels, and drought-tolerant landscaping
Concept rendering
Floor plan of the 1,199 sq ft ADU: a 14 by 10 foot main bedroom with its own bath, two more bedrooms and a second bath, an open kitchen with island seating, a 15 by 16 foot living room, laundry, and a side patio
Floor plan

1,199 sq ft

3 bedrooms · 2 bathrooms · 50 × 26 ft

From $425,000

Where your city allows this size. City impact fees apply.

Included in the starting price

  • Design and coordination
  • Foundation
  • The home itself

Estimated for your property, in writing, before you commit

  • City fees
  • Utility connections
  • Solar panels (required for new detached ADUs)

Starting prices assume a standard site: utility trenching up to 50 ft, a level lot with workable access, and a slab foundation on typical soils. Also in development: 500 and 1,000 sq ft, pricing TBD based on interest.

Get your estimateSee if it fits your lotFull pricing details

Joining is free and non-binding. It's how we prepare your estimate.

Get started

Save your spot in the Founding Cohort.

Free to join. No deposit. Leave anytime before you sign.

What happens next

  1. We look at your lot. Your address and preferred size help us check what fits.
  2. Your cohort forms. Up to ten homes within about 50 miles. Construction can begin once three homes sign agreements.
  3. You decide. Review your site, design, and full costs, then choose whether to build.

Good to know

Questions, answered.

Does joining commit me to anything?

No. Joining is free, with no deposit. You decide whether to build only after your site review and cost estimate.

Who builds my ADU?

Construction is performed by our vetted network of licensed contractors. ADUStack provides the design, project coordination, and selected materials, and stays your one point of contact from start to finish.

What warranty comes with my ADU?

Warranty terms are being finalized. You’ll have them in writing, as part of your agreement, before you commit to anything.

Can I customize the plan?

The floor plans are set, so design and materials can be shared across the cohort. Lofts, two-story ADUs, and ADUs above a garage are custom options, priced after a feasibility study.

How long does it take?

It depends on your city and your site, so we won’t promise a schedule before your site review. One fixed point: California law requires cities to approve or deny a complete ADU permit application within 60 days.

What if an ADU doesn't fit my lot?

You’ll know early. Check Your Lot shows your lot lines and setbacks, and the site review confirms what fits before you commit to anything.

Already have a quote from another builder?

Send it for a free personal review of what it includes, what’s unclear, and what to ask before you sign. Free bid review

All questions Full pricing

Not ready to join yet?

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Seven categories to compare any builder's quote, line by line, so you know what's included before you sign.

Free guide. No obligation.