How To Build an ADU - Where to Start your Accessory Dwelling Unit

Almost everybody asks me where to start their ADU. You have to draw up floor plans, fill out paper work for permits, get financing, and make about 1000 decisions - so it’s hard to know where to start.

When Kol Peterson, author of the definitive guide to building an ADU, got the question… his answer was clear.

You have to figure out the cost of what you want to do, then think about financing. And you bounce back and forth between those two things until you have a project you love, that you can afford.

Watch the video to hear it from the ADU expert himself.

4 First Steps to Building an ADU

  1. Estimate ADU Costs
  2. Secure Financing for the project
  3. Research zoning requirements
  4. Consult with a builder or designer/contractor who has ADU experience
 

ADU Costs - how to figure out your ADU costs

Kol talks about figuring out the ballpark ADU costs. He knows it’s a bit difficult to come up with a figure when you haven’t nailed all the details out. But this is where he suggests you start.

Are you doing a detached ADU with custom construction? Or prefab/modular installation?

Are you converting part of your existing primary home into an ADU (like a garage or basement conversion)?

I’d recommend you use 3 simple techniques to quickly estimate how much it costs to build an ADU:

  1. Example quotes sheet - Check out the sample costs for typical projects from our friends at BuildZig

  2. ADU Cost Calculators - The County of San Mateo cost calculator or the Napa/Sonoma ADU Cost Calculator developed by the Napa Sonoma ADU Center.

  3. Average actual ADU costs of finished projects - Study the figures other real homeowners have reported for their ADU costs

It gives you a ballpark estimate that you can use to move forward…

ADU Financing - How to pay for your ADU

There are a lot of ways to pay for the construction of your Accessory Dwelling Unit.

During the COVID-19 quarantine, mortgage rates hit all time lows and we had a mortgage specialist do a Q&A for How To ADU subscribers.

Right now, a lot of California homeowners are in a perfect place for a cash out refinance which does TWO things for them:

  1. They get some cash to finance the construction of their Accessory Dwelling

  2. They lock in a new lower mortgage APR

ADU permit restrictions and red flags

There are two great segue ways here:

  1. Learn about the new California ADU laws that make it easier to build an ADU

  2. And take the How To Build An ADU Online Course taught by Kol Peterson

Once you’ve figure out your broad costs and financing, you have to start researching what you can actually do.

If you want to learn everything you can, we highly recommend Kol’s online course. Follow the link above and you’ll save money (and I’ll get a referral credit for introducing you to the course!)

Or if you would like to keep learning on your own for a bit, check out this youtube video about the new ADU laws in California.

And in either case, you can subscribe to more free resources by joining our mailing list - just enter your email address below: