Adding a Duplex ADU to a 24-Unit Complex

[Patrick Collins]

Happy 4th of July weekend everyone!

While ADUs on single-family properties have become broadly understood in California (which is great!), multi-family ADUs still seem to lag behind. Since the ADU laws in CA included multi-family properties in 2020, we have been working with owners and managers across California to develop multi-family properties with ADUs, in various ways within the constructs of the current legislation. We've worked on ADU projects in most major jurisdictions throughout California, so we thought that it could be helpful to many in this group who are considering an ADU (or multiple ADUs) if we would start to share some of the actual data and process behind these projects, especially those that are less common like multi-family projects.

We thought this duplex ADU that's just finishing up in Buena Park (Orange County) would be an interesting project to start with for the group. This project is two ~650sf 1bd/1ba ADUs in the rear of a 24-unit complex. The project ended up costing about $200k per unit ($400k all-in) and each unit will rent for $2,200 per month. The project was completed from design and permitting to construction in 12 months. This was about 8 months in design and permitting and just under 4 months in actual construction. This could have gone much faster in permitting, but we were told that this duplex ADU was the first of its kind that the city of Buena Park had approved. We are working on a few other similar projects in the city now.

See the completed photos below...

And here are a few that we have from the construction process...

I'm happy to answer any questions about this project or others in California!

Have a great 4th!

PC