What are the Benefits of Converting an Existing Garage to an ADU?

By Sean Canning

I wanted to make a quick video to explain some of the benefits that come with converting an existing garage on your lot (or on a lot that you’re potentially buying) into an accessory dwelling unit (ADU) in San Diego.

So first off, under the new accessory dwelling unit regulations, you can convert an existing garage (attached or detached) to a junior accessory dwelling unit, or even an accessory dwelling unit.

So what this means is you can take a lot that has one home and a garage, and make that into a lot that has two homes. And you can rent one and live in the other, or live in that one and rent the other one, it doesn’t matter.

But this is an easy way to increase the rental income (or at least increase the flexibility on your lot).

Now, one of the major benefits is that if that existing garage is in the side yard, or rear yard, or front yard setback, you don’t have to move it. So this is an exception to building inside those setbacks with an accessory dwelling unit.

Now, one of your biggest challenges doing this is going to be your utilities.

And the most complicated is definitely your sewer because the sewer has to work with gravity. So you’re going to want to make sure you plan a way for your sewer to get back to the sewer lateral so that you can build out that bathroom.

Water is much easier and electricity is fairly easy, and of course all the low voltage stuff is very easy to achieve.

Now the next thing that you need to be aware of is what kind of fees are going to come into this.

So, as we discussed in the other videos, there’s four fees you are subject to.

Impact fees are exempt for ADUs and JDUs, so now we’re down to three fees.

Sewer and water fees, you’re going to pay 50% of the fees that you would pay on a dwelling unit. So that is going to be $3,600, or I think it might’ve just went up to $3,700 for your sewer and water fees when you add one of these new units.

School fees, if you can keep it to 500 square feet or less, you’re going to be exempt from school fees.

Otherwise, those would be $4.8 cents for all of the square footage of that new unit. So if you go to 501 square feet, it would be $4.8 cents multiplied by 501 to understand your school fees. And the last fee to be aware of is your plan check and inspection fees, which are going to be consistent regardless of whatever type of typology you’re building here.

So this is a really great way to add an additional unit on the property. And the only other thing we should discuss here is what happens with the parking that was in that garage.

Well, in certain cases that parking can be now in the driveway that was right before the garage. If your garage was off the alley, that may not be an option for you. But potentially you have more area on your lot where you can add those off-street parking spaces.

There is a little loophole in the municipal code which talks about how you would not have to replace this parking.

So there’s a scenario where the dwelling unit requires two parking spaces which are both in that garage. You want to convert the garage to the accessory dwelling unit or junior accessory dwelling unit, but there’s nowhere else to put the parking on your lot.

Well, if that’s the scenario, you can leverage that loophole and you can go with a zero parking condition.

So make sure you dive deep into Chapter 14: Separately Regulated Uses under Residential Uses, to understand all of the accessory dwelling unit and junior accessory dwelling units regulations.

Now there’s one more thing I want to tell you, and this is kind of up for debate because we’ve gotten different answers from the Development Services Department in the City of San Diego. But it seems like there could be an outside loophole to attach a junior ADU to the garage, or maybe build out the junior ADU as half of that garage (if it’s a two car garage) and then potentially demo the rest of the garage, or even leave the garage.

And this seems to be a loophole to get a detached junior accessory dwelling unit, which otherwise would be prohibited because it would have to be attached. Of course, detached carries more value.

So if this is a loophole you’re interested in, I would recommend setting yourself up with a virtual over the counter meeting with the planning department to discuss that.

And then the last thing I’ll mention just for context here, a two-car garage could become a nice one bedroom unit. A one-car garage could become a small studio unit. And if you have more than a two-car garage, you can use your imagination to see how far that would go.

And in conclusion, these are some of the benefits to converting an existing garage into an accessory dwelling unit. 

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