San Jose · South Bay · Peninsula

You don't want to spend six figures and end up with something that looks like a shed in the backyard.

This is the guide for Bay Area homeowners who want a designer ADU — not a backyard box.

It walks you from zero — what the types are, what they cost, how permits work, how people pay for them — and then hands you a clear standard for judging which builders actually deliver a home that looks intentional.

Start with the designer ADUOr start from the very beginning
Wide exterior view of a detached backyard ADU with a low single-slope roof, vertical cedar siding, and full-height glazing facing a small garden courtyard
The whole point of this site: backyard buildings that read as architecture, not storage.

Why this guide exists

I went looking for straight answers about building an ADU in the South Bay and found two kinds of pages: city documents written for people who already know the vocabulary, and contractor landing pages that answer every question with "contact us for a free estimate."

So I started researching it properly — reading the code changes, comparing cost breakdowns, and looking hard at hundreds of finished projects to work out why some backyard units look like a considered piece of a home and others look like a shipping container with a door.

I'm not building one myself and I'm not an architect. I'm the person who did the homework first. Everything here is written for someone who started looking last week: first the homeowner basics, then the company profiles and questions that make a quote easier to compare.

Start here

The basics — what I didn't know when I started

The heart of it

The two pages that separate a designed ADU from a box

  • The signature piece

    How to build an ADU that doesn't look like an ADU

    Roofline, proportion, window rhythm, siting, materials. The specific, nameable reasons cheap ADUs read as sheds — and what the good ones do instead.

    Read it

  • The checklist

    How to choose a designer-ADU builder

    A reusable 8-point checklist for telling a builder who delivers the intentional look from a general contractor who will hand you a box.

    Read it

Company research

Builder and prefab company profiles are live

I am working through ADU builders, prefab companies, modular manufacturers, and preapproved-plan vendors one profile at a time. These are research profiles, not paid rankings: each one explains why the company appeared in the data and what you should verify before requesting a quote.

Browse company research profilesStart with San Jose

Want a shortcut?

Tell me your lot, your budget range, and the look you're after. I'll point you toward the builders worth your first conversation.

Get a quote or free consult