The Truth About ADU Costs

Accessory dwelling units are increasingly popular throughout California as counties are encouraging in-building to create more housing. If you’re considering investing in an ADU in the Bay Area, no doubt cost is one of the most important factors in your decision-making process. Because this is a significant investment of often more than $20K for our clients, you should prepare yourself for the realities and the chances of surprise costs.

Architectural ADU Costs

Before the building can begin, you should understand that there are some costs associated with designing and permitting well before the foundation is laid. The very first thing you will need to do is hire an architect to create the plans. Choosing an experienced architectural firm is an important step in the process. You’re essentially building a small home from scratch, so the better prepared you are, the better the process will be.

Not all architects are ADU experts, and that can end up costing you more over time. It would be best if you find an architectural firm that understands ADUs from planning to construction. If you have the right partnership with your architect, they can help you stay on budget while designing all of the amenities you want. If you have a custom design in mind, costs will vary on size and your ADU’s overall vision. The more complex and customized, the more it will cost. We offer pre-designed ADU plans that are more affordable but offer the same quality that you expect from our team.

Other Costs

The additional things that will have an impact on your budget are obtaining permits for building and hiring a contractor to do the unit’s construction. For many homeowners, these are not tasks they have experience doing.

Once you have plans from your architect, you will need to get them approved by your municipality or county. Some architects may even charge extra for this step, so be prepared for that cost. In the Bay Area, seismic concerns may require soil tests to assure the neighboring properties that adding to yours will not affect there property.

Hiring a builder that understands the ADU niche is also another way to stay on budget. Depending on the location and size of your project, it could require some pretty extensive infrastructure additions: upgrading electrical, sewer, and water. Some areas have tight lot lines and could require making way for large equipment for digging foundations. You need a quality construction partner that will respect your existing property too.

Avoid Budgeting Surprises

One way to prepare for the cost reality of an ADU is to find a firm that can handle everything for you. Hiring several firms to handle each step in the process can drain your time and budget. DCA’s end-to-end project management services help clients maintain a predictable schedule and budget while having an advocate working with your builder for all those last minute decisions.


Get in touch with us. We would love to help you get your project off the ground