Now, let’s get into attached ADUs which offers a completely different experience.  

Imagine driving up your driveway on a sunny Saturday late afternoon with the car full of groceries.  As you enter the house, you hear sounds of talking and laughing.  You holler that you need help with the groceries and two of your “responsible” family members come out to make quick work of this task. 

As you enter the house and head to the heart of the home, the large open concept kitchen and family room.  As you plop grocery bags down on the dining table, you do a happy dance as you smell the scrumptious scent of double chocolate cake, the dessert that your mother-in-law was baking for the family dinner night. 

While groceries are being put away, you and hubbie roll up your sleeves and start making the lasagna, garlic bread and salad fixings in between breaks of being pulled away when you hear a cheer or groan go up about the NHL game being watched by the kids and grandparents.

This is one type of experience that can come with an attached ADU. 

This type of ADU is added onto your existing home on your property. 

Now, there are zoning requirements that this type of ADU can only be up to 50% of your main home square footage. 

But, honestly, there are ways around that because this type of ADU offers some flexibility.  Let’s say, your existing home was 1000 sq feet and wanted to add a 800 sq ft ADU.  Well, this requirement would restrict you to up to 500 sq ft ADU, right? 

Maybe.  I say, maybe, because with a little creativity, you can shift the square footage around and do a combination ADU and main house remodel/addition.  You can add to your existing house to meet the requirements for the sq ft you want for your ADU. 

Also, with an attached ADU, the line where the ADU starts and where the main house begins is really kind of a formality meaning you can add what can’t be added to your ADU to the main house area.

That flexibility is one of the benefits of attached ADUs.  We have a 1 bedroom ADU and a 4 bedroom main house.  But, because it is attached, we can split it how we want.  

Attached ADU’s are great for multigenerational households, especially if they are thoughtfully designed to allow for communal connecting areas as well as privacy. 

In our house, the master bedroom for my husband and I are at one end of the house while the bedroom for my in-laws is at the other end of the house. 

This “wing” concept is great for attached ADU’s. 

Another option is to take the “wing” concept and add a second story ADU. 

This type of ADU can afford more privacy but noise for the first floor can be an issue.

Attached ADU’s can also be used as a rental, too.  As a matter of fact, our 1 bedroom ADU is currently being used as a short-term rental.  

Another upside to attached ADUs is that the construction costs may be lower because in many cases, the ADU uses the existing electricity, water and, HVAC systems.  There is an augmentation rather than an entirely new system which can help with costs.

Also, remember how I talked about the loss of your backyard space? 

Well, depending upon how you design your addition, you will lose some of the backyard space but it is often not as big of an impact as a detached ADU. 

For us, we designed our ADU addition to hug the setback to leave as much yard as possible.

But what are the downsides? 

Well, there are a couple. 

Whenever you touch an existing house, especially an older home, some surprise repairs may crop up. 

For instance, for our new ADU area, we wanted copper pipes but the old main home had 100-year-old galvanized pipes which we ended up replacing. 

Another downside is that attached ADU’s don’t offer the privacy possible with a detached ADU. 

There are ways of careful design to mitigate that issue.  A separate entrance does offer privacy. But, noise can be an issue and impact acoustic privacy. 

For instance, our ADU unit is next to my teenager’s bedroom and he can be loud while gaming online with his buds.  So, we had to add acoustic panels and are considering whether we need to switch him to another room to control noise issues for the rental unit. 

Not to mention, we won’t be able to freely holler for a towel or sing at the top of our lungs to “?’ on that side of the house.

Accessory Dwelling Unit (ADU) type #3: Garage Conversion ADU

Before we get into this next ADU type, I want you to go to your garage. 

What do you notice? 

Is the garage being used to house your cars? 

Or is it being used to house boxes? 

Maybe it's just me, but I swear every time I go do my laundry, it seems like the boxes had babies.

It may be hard to believe, but the garage space can be converted into a stylish studio pad perfect for a young adult kid or to rent out. 

Garage conversion ADUs can be the most inexpensive option in terms of construction costs provided that the structure is in decent condition and there aren't any foundation issues.

Most garages range from 180 sq ft (1 car garage) to 400 sq ft (2 car garage) or more. 

To be honest, ADU garage conversions work best for garages that are at minimum a 2 car garage.

With clever design to make small spaces feel large, like a kitchenette with petite appliances (18 inch dishwasher) or indoor outdoor living with a large sliding door opening up to a sweet backyard patio, it really is possible to transform that dark, cluttered space into a stylish studio.

If you are ambitious, you can even turn that garage into a two-story ADU, with the first story being an open concept family room, kitchenette, ½ bath area and the second story for 1 to 2 bedrooms with bathroom. 

Isn't the loft style design with the cute spiral staircase so amazing? 

Not only is it super stylish, but it keeps things open, with a spacious feeling and bright. 

Keep in mind, though, that adding a second floor comes with additional costs and this no longer fits in the least expensive ADU category.

One question related to a downside to garage conversion ADUs is where are your boxes going to live? 

Garages are great for housing cars but also storing things like a table saw or the kid’s childhood keepsakes.

There may be the hassle of covering your car or having to purchase a storage shed or build built-ins to house your treasures. 

OK, yes, yes, for us, it would mean a second storage shed and built ins!  Hoarder much?  😀

Accessory Dwelling Unit (ADU) Type #4: Jr ADUs

OK, I am going to let you in on a little known fact that can Blow.  Your.  Mind with Jr. ADU’s.  

First off, what is it? 

It is like a baby attached ADU that can be up to 500 sq ft within the exiting footprint of your house. 

It must include a kitchen and sleeping area.  It can have its own bathroom or share a bathroom with the main house. 

Remember our talk about garage conversions and how 2 car garages are around 400 sq ft?  Wouldn’t that be an easy way to add a JR ADU?

The best part? 

You can have this Jr ADU as part of your existing house AND you are allowed a detached ADU on your property! 

What does that mean? 

You could pretty much turn your Single Family Residence into a triplex if you so choose!

Did I blow your mind?

Now, just because you CAN do it, doesn’t mean you should. 

Depending upon your lot size, that could feel really crowded. 

Not to mention the parking headaches with 3 units and who knows how many people living on the property. 

Talk about space and privacy issues! 

But, it is an option, and depending upon your lot size and careful design, it is pretty amazing to think of the possibilities.

I do need to mention an important downside with Jr ADUs. 

When you do a JR ADU, you are committing to owner occupancy!

The other ADU types do not have this requirement with the new California regulations but this JR ADU does require this. 

So, if you were intending to do build a Jr ADU at a rental property, it is NOT a good option.

Conclusion

Aren’t the possibilities with accessory dwelling units in California intriguing? 

We covered how detached backyard cottages can be one or two story and up to 1000 sq ft if 4 foot side and back setbacks are met. 

The biggest benefit of a backyard cottage type of ADU is its privacy! 

I mean, people from the street can’t even see your cottage hidden in the backyard. 

And the locked gate with nest doorbell keeps out the riffraff like your mom (j.k. love you mom) or the always a nuisance paparazzi. 

It’s a great set up for a rental with you living in the main house and renting the cottage or you living in the brand spanking new backyard cottage and renting out the main house. 

The second type of ADU home is attached to your existing house.  Using the concept of separate “‘wings” along with communal spaces, this is a great setup for multifamily/multigenerational households. 

Although this ADU must be 50% or less in terms of sq footage of the existing home, this can be mitigated with some creative design. 

It can be used as a rental unit but comes with challenges related to noise and privacy. 

A version of the attached ADU which could be the least expensive option is the one-story garage conversion with a solid structure and no foundation problems.  It is hard to believe but the dark, dusty garage space can be transformed into a stylish studio apartment perfect for young adult kids or to rent. 

There is also the option of a two-story garage conversion with bedroom(s) on top, but be aware that this is an expensive upgrade. 

And last, but not least, is the baby JR ADU which must be less than 500 sq ft and be housed within the existing footprint of your property. 

Although this may seem the most insignificant, it packs a big punch in that you can have a detached backyard cottage ADU AND a JR ADU!  Triplex anyone?

Hope this article opened your eyes to the possibilities of the variety of California Accessory Dwelling Unit options.

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