ADU Strategies in San Diego

[David Frandsen]

Hello BP investors. I'd like to hear from those that have experience with Accessory Dwelling Units. I'm in San Diego County. I started to research the requirements for Chula Vista (have not reviewed other cities yet). I have a basic understanding of the requirements but was wondering about permitting costs. Finding a property with a detached garage that can be converted seems like the way to go.  This property would be my primary residence for the purpose of house hacking. Any other input would be much appreciated. 

[Whitney Hill]

Hey there, I wanted to share some ballpark ADU construction costs in case helpful. A 400sqft garage conversion has been running $75K all-in... that's $160/sqft + $13K for design+fees. 700sqft would be around $125K all-in... this is for a typical conversion, the footings + structural work could change game in your case.

Numbers on standalone ADUs split out as well in case helpful...

Pre-construction costs: 

-Design: if using a stock plan, the design work costs about $5K. If going with a full custom plan (e.g. you have a unique lot layout that will require a customized layout)… closer to $10K. Even if you use the county/city standards... if one spec changes, you'll need to have new plans drawn up plus go through the "regular" approval line for permits
-Permits: though some fees are waived, there are still fees like those to schools (typically ~$4/sqft). $2-4K is typically what the total costs to the city will run for an ADU

Construction costs
-Building costs: typically $250/sf to start, for vertical building only. This is higher than for single family homes, since the cost is spread out over a much smaller footprint (e.g. still a kitchen+bath, but only 1-2 BRs).
-Site work: typically $10K is a good number to start with, which includes preparing the building pad, connecting utilities, plus a small amount of landscape and concrete work.

Hope this helps!