Concrete Porch

About Us

At ADU Collective, our goal is to streamline the process while considering the unique needs of each project. With extensive experience in conversions, additions and new construction, we have permitted a multitude of ADU's throughout the Greater Bay Area.

Depending on your specific needs, and whether your ADU will include a garage conversion, addition, or new construction, costs will vary. We find that most ADUs will fall somewhere in the range of $170,000 to $300,000. You can see a breakdown of example project costs in this presentation or visit this website created by San Mateo County that is an easy to use ADU calculator​.

Once design is complete and permits approved, construction moves quite quickly. We find that most projects can be completed within 12 months. The design portion can vary depending on client needs. A simple conversion can take just a few meetings to develop a plan that works for a client, but we find most projects have custom considerations that take a little longer to work out together. A good estimate is to allow about twelve weeks for design and submittal to the building department.