What an ADU really costs, and where the money goes
California's statewide survey of ADU owners found a median build cost of $150,000. A public pilot in San Diego spent $176,333 on a one-bedroom. Neither number is the one a builder will quote you first. This guide explains why, and what to budget for.
4 min read · 3 sourcesRead the guide
Five real ADU projects, broken down line by line
A public housing agency built five ADUs and published every cost. Here is what they paid for permits, surveys, design and construction.
3 min read · 2 sources
Prefab vs site-built ADUs
Factory-built units can be faster and sometimes cheaper. The savings depend on your lot, your city and what the quote leaves out.
3 min read · 4 sources
How people actually pay for an ADU
Most owners use cash or home equity. Here is how the main loan options work and what lenders will count.
3 min read · 6 sources
ADU rental income and payback
What ADUs actually rent for, how to run the numbers on your own unit, and the rules that limit short-term rentals.
3 min read · 6 sources
JADU, attached or detached
A junior unit inside your house costs a fraction of a backyard cottage. Here is what each type allows and what it gives up.
3 min read · 3 sources
How long ADU permits really take
State deadlines say 60 days in California. Real projects take longer. Here is what to expect and how to keep yours moving.
3 min read · 4 sources
How big and how tall can your ADU be?
The size, height and design rules that shape most ADUs, with the state minimums cities have to allow.
3 min read · 5 sources
Utilities, sewer and power
Connecting an ADU can cost a few thousand dollars or more than the unit. Here is how to find out which before you sign.
3 min read · 3 sources
Setbacks, HOAs and deed restrictions
What your homeowners association can and cannot do, how setbacks work and why you should read your deed before you design.
3 min read · 4 sources
ADU insurance and property tax
Your homeowners policy may not cover a backyard unit well, and your tax bill will go up. Here is how to plan for both.
3 min read · 4 sources
ADU rules in California, Oregon, Washington, Texas and Florida
Five states, five very different approaches. What each state requires of cities, and where you still need to check local rules.
3 min read · 11 sourcesThe Backyard Letter
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