Best Cities in San Diego County to Build an ADU (All Cities Ranked)

ADUs are booming more than ever in California. Helping lead that charge is San Diego County.

As California’s second most populous city, it’s no wonder the county is pushing ADU development for its residents. But is every city complying and supporting homeowners who want to build an ADU?

Even with the entire state of California mandating and incentivizing certain aspects of ADU development, some cities still prefer to go rogue with their own policies (whether they have the standing to do that or not).

We set out to see if any cities in San Diego County are following suit with state law, going rogue, or even going above and beyond to support ADU development. How? We created an ADU Friendliness Score to rank each and every incorporated city on how they’re embracing ADUs (or not) and whether they’re a good investment for your real estate portfolio. (That means we did not include any unincorporated cities or Census Designated Places.)

At the bottom of this article, you can find our breakdown of every aspect of our scoring, along with proper sources and methodology.

The gist of the scoring:

• ‍50 = Perfect‍
• 40-49 = Excellent‍
• 30-39 = Great‍
• 25-29 = Good‍
• 20-24 = Okay‍
• 15-19 = Bad‍
• 11-14 = Terrible‍
• 10 = Avoid at all costs‍
• 0-9 = Impossible because 10 is the lowest the scoring goes

We’ve taken up enough of your time. Let’s get onto the rankings, starting with the county’s Friendliest ADU city…

San Diego

Coming in at number one is, no surprise, the city of San Diego. The most populous city by far in the county, San Diego is obviously going to be hit by the state’s housing shortage the hardest, thus it has had to find a solution the fastest.

And they’re going all-in on ADUs.

San Diego ADU Development Accessibility

San Diego is leading the charge by:

• Offering multiple incentives for building ADUs (the ADU Bonus Program and the SDHC’s ADU Finance Program), plus pre-approved ADU plans.
• Allowing exceptions (albeit rare) for converted units to exceed the state-wide maximum square footage for ADUs.
• Allowing a property to have 3 total ADUs on the property–2 more than the state-wide maximum (1 attached or detached, 1 conversion, and 1 JADU).
• Having incredibly in-depth and user-friendly public information on & off their website to help residents navigate the waters of ADU development.

ADU Accessibility Score: 21/25

San Diego ADU Rental Accessibility

Now when it comes to the rentability of ADUs in San Diego, it’s a solid option for you prospective landlords. Here’s why:

• San Diego has one of, if not, the strongest rental market in the county (which makes filling vacancies less of a hassle than other cities).
• The ROI for each unit size (from Studio to 3-Bedroom) is above-average for the San Diego County market, making it a worthwhile investment.

ADU Rentability Score: 20/25

Overall San Diego ADU Friendliness

San Diego is making waves in the massive ocean we call real estate, always looking for ways to innovate and include. With the city’s lean policies on ADUs, strong investment potential and proactive approach to evolving housing trends, there’s no question that San Diego should be your first consideration as you dive into the world of ADUs.

AND we’re going to give San Diego a bonus point because, why not?

Thanks to AB1033, San Diego is the first and only city in the county to allow the sale of ADUs as condominiums. Whether your plan is to sell or at least have the option to as needs change, San Diego isn’t just your best option; it’s your only option.

Bonus Score: +1

Total ADU Friendliness Score: 42/50

Carlsbad

In second place, we have the beautiful beach city of Carlsbad.

Though Carlsbad isn’t too close in proximity to San Diego, it’s sure inching closer and closer to San Diego’s standard regarding ADU acceptance. Closer than any other city inthe county, and that’s for good reason.

Carlsbad ADU Development Accessibility

The city of Carlsbad is quick to adapt to California’s statewide ADU regulations. Plus, it goes even further by:

• Making things easy for owners and builders with easily accessible pre-approved ADU plans.
• Having clear and user-friendly ADU information on the city’s website, with contact information for building department staff and links to relevant resources. There's even a comprehensive fact sheet you can download and print out.
• Allowing, in some instances, ADUs to be several feet taller (25 ft.) than the state’s recommended height (16 ft.). If Carlsbad’s lovely ocean views are important to you or your renters, this is a huge win.

ADU Accessibility Score: 17/25

Carlsbad ADU Rental Accessibility

If your goal is to build an ADU for rental income, Carlsbad is a great place to do so. We gave it the 6th highest score overall for Rental Accessibility.

Contributing to Carlsbad’s ADU rental appeal:

• The ROI for newly built ADUs in Carlsbad is above-average for the county, ranging from nearly 26% for studios to 18% for 3-bedroom units.
• Carlsbad is somewhat open to short-term rentals, and ADUs built prior to 2020 can be eligible with a permit.

ADU Rentability Score: 19/25

Overall Carlsbad ADU Friendliness

Carlsbad is an extremely ADU-friendly city. It quickly adapted to the growing trend and adopted the state’s regulations as per the ADU handbook, even going a step further by allowing taller ADUs than other cities–perfect for a beach city with stunning views.

Despite not having any ADU grants or incentives, the city clearly directs interested parties to Cal HFA’s ADU Grant Program from their info-packed ADU webpages.

Building an ADU in Carlsbad, whether for personal reasons or for rental income, is a great choice.

Total ADU Friendliness Score: 36/50

Encinitas

Located in North County, this beachside city of 60,000 has a laid-back vibe and an “artsy bohemian” flair, making it an especially good cultural match for the alternative housing option ADUs provide. Backyard cottage rentals are the perfect housing option for everyone from surf bums (we use the term endearingly) to small families seeking creative housing solutions. 

Encinitas ADU Development Accessibility

Building an ADU in Encinitas should be a straightforward experience, with some added support from the city in the form of: 

• Pre-approved ADU plans and an easily accessible website for finding just about anything you need in regards to ADUs.
• They’ll direct those looking to build an ADU in Encinitas to financial incentives/grants through CAL-HFA.
• Low impact fees and property taxes.
• Following the state’s ADU guidelines to a T.

ADU Accessibility Score: 17/25

Encinitas ADU Rental Accessibility

An ADU is a safe and solid investment in Encinitas. Here’s why: 

• Encinitas has a very middle-of-the-road rental market. And “middle-of-the-road” is good if you want stability and predictability. 
• The ROI potential in Encinitas is very healthy. It’s safe to expect around 20 or 25% depending on the size of your ADU.
• Owners looking to find tenants and collect ADU rent should be able to do so pretty reliably in Encinitas. 

ADU Rentability Score: 18/25

Overall Encinitas ADU Friendliness

What makes Encinitas a pro-ADU city isn’t that they go above and beyond in every way possible. It’s how quickly they responded to the demand for ADUs and adapted to the statewide regulations that followed. Plus, with a steadily average rental market and a healthy ROI for whichever size ADU you choose, Encinitas gets a big thumbs-up.

Building and renting out your ADU in Encinitas should be a breeze… at least as “breezey” as residential construction gets.

Total ADU Friendliness Score: 35/50

La Mesa

La Mesa, “Jewel of the Hills,” comes in strong in the number four position. 

With extensive resources for ADU development and a healthy rental market that even allows for short-term rentals, this community, just 10 miles inland from the Pacific Ocean, is eagerly welcoming ADUs into its housing landscape. 

La Mesa ADU Development Accessibility

La Mesa embraces ADU development by: 

• Not only offering pre-approved ADU plans, but making the options available to easily check out on the city’s ADU website, complete with drawn renderings. 
• They also took it a step further and created a downloadable ADU guidebook. At a hefty 65 pages, ADU builders in La Mesa are likely to find any info they need in this document. 
• ADUs in La Mesa can be taller than the average around the county–up to 20 or 30 ft. 

ADU Accessibility Score: 21/25

La Mesa ADU Rental Accessibility

As an owner, La Mesa can either be the absolute best place in the county to build an ADU for rent, or it can be kind of meh. It depends on your goals: 

• A strong rental market means earning steady ADU rent should be do-able, but at the same time the ROI for La Mesa ADUs is lower than most of the county. It sits at around 20% for studios and closer to 15% for one or more bedroom units.
• This is the only city in San Diego County that has few-to-no restrictions on ADUs as Short-Term Rentals (STRs). So if you’ve got your sights set on building an ADU for vacation rental income, La Mesa is the place to do it. 

ADU Rentability Score: 12/25

Overall La Mesa ADU Friendliness

Building an ADU in La Mesa is a solid option, receiving the second highest ADU Accessibility Score in all of San Diego County. So, if your goal is to build an ADU or two on your property for family or other personal reasons, there’s almost no going wrong with La Mesa.

However, if you’re banking on making passive income by renting out your ADU(s), you have better options. The ROIs per unit size are certainly nothing to scoff at, so La Mesa isn’t a “wrong” option by any means, but other cities may give you a bigger bang for your buck.

That is, unless you're all-in on the vacation rental business, then you really don’t have another option, thus, earning La Mesa the last bonus point in this article. Of course, do your due diligence before building an ADU for the purpose of renting out as an STR, but this option alone makes La Mesa a stand-out ADU city.

Bonus Score: +1

Total ADU Friendliness Score: 34/50

Chula Vista

One of San Diego County’s fastest growing cities, Chula Vista has historically been more welcoming to ADUs than other towns in the area, but a recent city council vote against increasing the number single-family homeowners can build indicates some slow-down. Local officials who objected to more ADUs raised concerns about increasing the density of neighborhoods and the resulting pressure that might put on resources like schools. 

Still, there’s a lot to celebrate here. Take a look:

Chula Vista ADU Development Accessibility

While local officials are beginning to tighten the restraints on ADU development, building a straightforward backyard cottage is completely encouraged in Chula Vista with:

• Grants to low-and-moderate-income Chula Vistans (No longer available as of 2024, but their previous existence demonstrates the local government sees the benefit of ADUs for providing affordable housing).
• Up to three ADUs allowed per single-family property–one detached, one attached or conversion, and one JADU. 
• Pre-approved ADU plans available.
• ADU height maximum capped at 20 ft., of course, with caveats (which you can read here).

ADU Accessibility Score: 17/25

Chula Vista ADU Rental Accessibility

Building an ADU for rent in Chula Vista can be a great passive income strategy if you’re in it for the long game. Here’s why:

• You’re likely to find tenants relatively quickly with Chula Vista’s very strong rental market.
• Compared to other cities in SD County, the ROI per ADU size isn’t the highest, but for 1-3 bedroom ADUs, you can expect an average, on-market return with your rentals.

ADU Rentability Score: 17/25

Overall Chula Vista ADU Friendliness

The only bump you may hit on your ADU development road is from local officials and some neighbors, but with the state on your side, your process should be mostly smooth. And with a growing population and a strong rental market, you can expect to make a healthy return by renting out your ADU in Chula Vista, even if the ROI isn’t a home-run.

Total ADU Friendliness Score: 34/50

Del Mar

Moving out of the top five and south only a few miles, we have our sixth friendliest ADU city: Del Mar. This opulent city is incredibly welcoming of ADUs offering incentives, but comes just shy of the top five.

Del Mar ADU Development Accessibility

Del Mar is mostly accepting of ADU development, with only one major criteria getting in its way of scoring higher on our list:

• Del Mar’s maximum ADU size is capped at 1,000 square feet. One of only four cities in the county under the state’s maximum of 1,200 sq. ft. outlined in the ADU Handbook.
• Their website is mostly okay, providing a lot of information and links to more information. It could just use some organizing to make it more user friendly and easier to find what you need.
• The city offers multiple ADU Programs to encourage ADU development, which you can read more about here.

ADU Accessibility Score: 15/25

Del Mar ADU Rental Accessibility

Here is where Del Mar really shines. You may want to consider listing your ADU in Del Mar for rent because:

• You can expect incredibly high ROIs for any ADU size (as low as 20% for larger sizes and 33% for smaller ADUs).
• Del Mar does have a relatively weak rental market. The city is heavily owner-occupied and high rents may push prospective renters to surrounding areas.

ADU Rentability Score: 20/25

Overall Del Mar ADU Friendliness

Del Mar is so close to being a top-tier ADU city. If they were to increase their max ADU size to 1,200 sq. ft. or more, they would easily compete with the likes of San Diego’s or La Mesa’s Development score.

Rentability-wise, Del Mar is hard to compete with. It may take longer to find tenants, but the income you can earn from renting your ADU makes the wait worth it.

In spite of the praise we’ve been giving Del Mar, we are deducting one point from their total. Shocking, we know. Their rentability is doing a lot of the heavy lifting here, and compared to La Mesa and Chula Vista, which share the same Friendliness Score, Del Mar doesn’t match up.

That said, do not overlook Del Mar when considering cities to build and own an ADU.

Bonus Score: -1

Total ADU Friendliness Score: 34/50

Solana Beach

This small beachside town of 13,000 is more tempered on ADUs than some of the heavy hitters on this list, and be warned that neighbors aren’t afraid to push back against their construction if a new ADU threatens their views. 

Overall Solana Beach is friendly enough to ADUs, following state laws, and a nice backyard cottage here can earn you good steady income from ADU rent if that’s what you’re after. 

Solana Beach ADU Development Accessibility

Solana Beach isn’t necessarily rolling out the red carpet for ADUs, but it does make them very do-able. The gist is:

• Statewide ADU laws are fully embraced via a local ordinance, which makes it clear Solana Beach aims to “incentivize and promote the creation of ADUs that can offer affordable rents for all household income levels.”
• No financial incentives for building ADUs or pre-approved plans are available, and there isn’t a ton of information available online through the city’s website, but a couple pdf’s detailing local laws and building requirements still provide a helpful framework.
• The only incentive, at the moment, is waiving fees for homeowners agreeing to rent out their ADUs as designated low-income housing.
• They allow ADUs up to two extra feet in height (18 ft. total) than the state norm.

‍ADU Accessibility Score: 13/25

Solana Beach ADU Rental Accessibility

Building an ADU for rent in Solana Beach isn’t a complete no-brainer, but multiple factors make it an idea worth serious consideration:

• A weak rental market overall, but when you do secure a renter, an ADU in Solana Beach provides a major ROI–you can charge some of the highest ADU rent in San Diego County, with most Solana beach studio ADU rentals going for $2,500 per month. The average ROI is between 20 and 30% for any size ADU.
• Making your ADU a short-term vacation rental is possible in Solana Beach. You just have to get a permit every year, and ensure your guests stay a minimum of 7 days (so, it’s technically more of a short-ish-term rental). 

ADU Rentability Score: 20/25

Overall Solana Beach ADU Friendliness

Solana Beach still has a ways to go when it comes to welcoming all aspects of ADU development. They’re good at following the state’s guidelines, but you have to dig a little bit to find their guides and documentation for building and permitting ADUs.

Where Solana Beach really shines (no pun intended) is their rental accessibility. Sure, their rental market isn’t the strongest, but when you find the right tenant (and if you’re a good landlord!), you can lock in some strong, consistent income.

With finding proper documents and securing tenants as your only downsides, you should have no problem building and renting out your Solana Beach ADU.

Total ADU Friendliness Score: 33/50

San Marcos

This suburban town is recently experiencing a lot of development and has a diverse housing landscape. Despite some more restrictive ADU design laws than other parts of the county, San Marcos still welcomes the ADU boom. 

San Marcos ADU Development Accessibility

Building an ADU in San Marcos can be an easy and rewarding process, keeping in mind:

• Permitting can be an ultra-simple process for a San Marcos ADU. You only need to submit a building permit, and pre-approved ADU building plans are available if you want to streamline the process even more. 
• The max size allowed is 1,000 square feet, a 200 sq. ft. decrease from the max allowed in other California cities. (An amount that can make a big difference! Think a big bathroom with a soaking tub, or a generous office space.)
• No ADU incentives to speak of.
• Detached ADUs can be taller than the state maximum, with a height limit of up to 20 ft. (with more exceptions than not) and attached or junior ADUs can be up to 25 ft., depending on the size of the main residence.

ADU Accessibility Score: 13/25

San Marcos ADU Rental Accessibility

Looking to collect ADU rent from your backyard cottage in San Marcos? That shouldn’t be a problem. Here’s why:

• San Marcos has a fairly moderate rental market, and with how quickly the city is growing, we wouldn’t be surprised if the market only got better.
• With most studio and one-bedroom San Marcos ADUs renting for just under $2,500 monthly and larger units averaging $3,700, you can expect to see a solid ROI.

ADU Rentability Score: 20/25

Overall San Marcos ADU Friendliness

Sure, there’s some catching up to do to match the state’s standards, but there are without a doubt areas where San Marcos stands out.

If you live in this city and want to build an ADU, you should have no problem doing so. Want to rent out your ADU in San Marcos? Even better.

Total ADU Friendliness Score: 33/50

Coronado

Coming in at halfway through the pack, Coronado is a beautiful resort city located on a peninsula in San Diego Bay. While there are somewhat strict ADU regulations, this city is worth highlighting for the high income potential for ADU rentals.

Coronado ADU Development Accessibility

With some restrictive policies but also a streamlined process for building an ADU, Coronado is a mixed bag when it comes to ADU development, offering:

• No specific incentives for building an ADU.
• A more restrictive policy than other parts of SD County in terms of how many ADUs are allowed on a single family lot–only one of any type of ADU. 
• Smaller maximum square footage than the state recommends (1000 sq. ft. max).
• Taller maximum height than the state recommends (18 ft., with exceptions).
• Pre-approved ADU plans, and a really straightforward permit application. (However, note the permit application is the only info about ADUs available online from the Coronado government. To find out about Coronado’s ADU regulations, you may need to dig into the official city code and/or visit the building department in person.)

ADU Accessibility Score: 9/25

Coronado ADU Rental Accessibility

As long as you play by the rules, putting your ADU up for rent in Coronado is a great financial investment, because:

• Coronado boasts the highest rents for ADUs in San Diego County, with typical studios going for over $3,000 monthly. 
• Your ROI will be high across the board, no matter what size ADU you opt to build. 
• Be warned: short-term rentals are strictly prohibited in Coronado. And apparently the city isn’t afraid to sue people who try to do STRs anyway. 
• The city also tries its best to discourage mid-term rentals as they’re the only city with a six-month minimum rental policy (every other city is a 30-day minimum).

ADU Rentability Score: 23/25

Overall Coronado ADU Friendliness

With all the restrictions and seeming development suppression for ADUs, you may want to avoid building one in Coronado. If you absolutely must, we recommend doing every bit of due diligence, comply with every rule and work in tandem with your builders to ensure you don’t rock any boats.

Because of the sensitive nature of building ADUs in Coronado, we’re going to deduct one point from their total. That said, once you get it built, you’re off to the races. List your Coronado ADU for rent and let the city’s lavish market do the rest.

Bonus score: -1

Total ADU Friendliness Score: 31/50

Poway

Poway is noteworthy for being almost entirely zoned for single-family housing (approximately 98%)--the highest percentage of single-family zoning in SD County. And they’re certainly welcoming ADUs. The city’s development services director told a local news station, “The lion’s share of our activity is individuals building ADUs on their own property.”

Poway ADU Development Accessibility

Poway encourages ADU construction by:

• Offering some ADU incentives in the form of reduced impact fees or even no fees for ADUs on the smaller size. (Impact fee reduction is now a statewide thing as of January 1, 2026 thanks to SB 543, but we’re still giving them credit for blazing the trail.)
• Allowing detached ADUs up to 1,500 square feet – the largest size allowance in the county (Most ADUs are capped at 1,200 sq. ft.). If size is one of your priorities, this is a big win.

ADU Accessibility Score: 17/25

Poway ADU Rental Accessibility

Building an ADU for rent in Poway can be a solid investment, but we won’t sugarcoat the reality, which is:

• Real talk, Poway has one of the weaker rental markets in the county. 
• Your ROI will likely be good, but not necessarily great–expect around 20% for studio and one-bedroom ADUs, and closer to 15% for larger units. Not shabby at all, but comparatively middle-of-the-road.

ADU Rentability Score: 13/25

Overall Poway ADU Friendliness

Poway is without a doubt an ADU-forward city. They go with the grain, happily follow the state’s recommendations and are active in adopting new pro-ADU practices.

The only thing taking Poway down a few pegs is their rental market. In San Diego, there’s really no such thing as a “bad” rental market, but within the county, it’s on the weaker end. Expect a longer waiting period to find tenants and recoup your money.

From a pure investment standpoint, you might have more luck building a rental ADU in another city, though you shouldn’t have a problem inside the city lines. If you’re building for personal reasons, Poway is almost as smooth as it gets.

Total ADU Friendliness Score: 30/50

National City

Located in the South Bay area, this oceanside city just 10 minutes from downtown San Diego has put in some special effort to welcome ADUs. While National City is a densely populated city that has struggled to meet its housing goals, it is still trying to do so with a mixture of new types of housing. Developers there completed 35 new ADUs in 2024. 

National City ADU Development Accessibility

Despite not having the strongest overall ranking on this list, National City is worth highlighting for some notable things it does in support of ADUs. Don’t sleep on them for:

• Having a streamlined ADU website with good coverage of all the information you need and who to contact for more. They also have a robust 20+ page downloadable ADU Handbook–points for going above and beyond.
• Creating some financial incentives for ADU builders, through things like its Density Bonus Program which targets projects building affordable units. 

ADU Accessibility Score: 17/25

National City ADU Rental Accessibility

If you’re aiming to collect ADU rent for your backyard cottage in National City, you can expect a reliable, if modest, income because:

• National City has one of the stronger rental markets in the county, so you’ll likely have no problem finding tenants.
• The ROI on National City ADUs is on the lower end countywide.

ADU Rentability Score: 12/25

Overall National City ADU Friendliness

National City is worth considering for any ADU endeavor you wish to pursue. They won’t give you a hard time with your development and if you’re patient with smaller rent amounts, you’ll get your money back eventually, making National City a worthy investment.

Total ADU Friendliness Score: 29/50

Imperial Beach

This South Bay beachside town of 25,000 residents is friendly to ADUs, mainly only ranking this low on the list because as an owner, renting an ADU in Imperial Beach will bring you a lower ROI than in most other parts of the county. 

Imperial Beach ADU Development Accessibility

Building ADUs in Imperial Beach should be a positive and straightforward process thanks to:

• Pre-approved plans and a website with links to resources.
• An online portal for submitting a building permit application for an ADU, no paper form. (This could be a plus or a negative depending on your personal preferences.)
• A generous height limit, with some ADUs allowed to be up to 25ft tall–significantly higher than what state law mandates.

ADU Accessibility Score: 15/25

Imperial Beach ADU Rental Accessibility

If you’re thinking building an ADU for rent in Imperial Beach could be a solid investment, you’re absolutely right. Here’s why:

• This sweet beach town is a desirable place to live, backed by a strong rental market.
• The ROI for an ADU rental isn’t great for smaller studio and one-bedroom units, which rent for around $1,500 in this part of SD county. However, larger 3-bedroom ADUs do better than the county’s average in terms of ROI and can garner well over $2,500 in monthly rental income.

ADU Rentability Score: 14/25

Overall Imperial Beach ADU Friendliness

The ADU building process in Imperial Beach is as straightforward as it gets. No officials should give you flack along the way. We would only suggest consulting with a professional (city official or ADU builder) if you’re not tech-savvy as the process is primarily virtual.

As for making rental income, it might be more of a waiting game. That said, 1-3 bedroom units in Imperial Beach are already smaller than the county’s average, hypothetically making over build costs a bit more affordable. That may justify the lower rent and add some cushion to your ROI (especially for 3 bedroom units!).

With the city and its residents used to smaller living spaces, ADUs fit right in, as will you for owning one.

Total ADU Friendliness Score: 29/50

Oceanside

This coastal city known for its great surf has been facing some debate over how to incorporate more affordable housing options like ADUs. A local paper, the North Coast Current, described a situation where an older couple built an ADU in their backyard so their daughter, a registered nurse and single mother, could move into their main house. 

Regardless of the various stances on the ADU-debate, here is where Oceanside currently stands when it comes to ADUs.

Oceanside ADU Development Accessibility

The city of Oceanside follows state law when it comes to ADUs, and beyond that offers a mix of helpful and “detached” (pun intended and you’re welcome) energy to those interested in building ADUs with:

• No special incentives. 
• A no-frills but still-helpful Accessory Dwelling Unit info page online through its Planning department, providing links to several important documents and resources to get started. 
• Following the state’s ADU guidelines without any pushback.

ADU Accessibility Score: 13/25

Oceanside ADU Rental Accessibility

Renting an ADU in Oceanside is a smart and reliable investment. We rated this beach town a 17 out of 25 for rental accessibility because:

• It has a strong, growing rental market with a big renting culture. 
• You can expect the rent you charge to steadily increase depending on the size of the ADU you’re renting and garner a decent ROI–middle of the road for the county, between 15 and 22%.
• Pro tip for renting: 1 and 2 bedrooms appear to have better ROIs than studios and 3 bedrooms.

ADU Rentability Score: 15/25

Overall Oceanside ADU Friendliness

Despite internal debate, Oceanside has a pretty lax approach to ADUs (very appropriate for a surf city). You won’t get pushback from anyone (except maybe from neighbors), while building your ADU. And only from looking at what’s publicly available, that’s about the furthest the city will go in helping you build your ADU.

Using your ADU for rent in Oceanside is completely justified. With the city’s growing rental market and borderline-decent ROI for any size ADU, you can’t really go wrong in Oceanside.

Total ADU Friendliness Score: 28/50

El Cajon

One of the larger suburbs in the county, El Cajon has a population of over 100,000. East of downtown San Diego and tucked in a valley surrounded by mountains, El Cajon distinguishes itself by supporting ADUs through a loan program and is, policy-wise, one of the more supportive cities on our list. 

El Cajon ADU Development Accessibility

El Cajon received some of our highest and lowest marks for different aspects of this category. The dynamic rating is due to: 

• The City of El Cajon has an ADU Loan Program that provides loans of up to $100k for homeowners building ADUs on their owner-occupied property. Nothing to sneeze at!
• The height limit for ADUs is higher, at 20ft, than most other towns in California.
• El Cajon has some good info about its ADU Loan Program online, but beyond that there isn’t an application or much general info about building an ADU in El Cajon available through the city’s website. 

ADU Accessibility Score: 17/25

El Cajon ADU Rental Accessibility

Listing your ADU for rent in El Cajon may be justified. We’d only encourage you to manage your expectations if you go this route because:

• A historically strong rental market means finding tenants shouldn’t be a problem.
• The ROI is much lower than in other parts of the county (one of the three worst on this list, based on our rankings). 

ADU Rentability Score: 10/25

Overall El Cajon ADU Friendliness

El Cajon is a mixed bag when it comes to ADUs. Their score is on the higher end when it comes to their policies and overall development process. It’s really the rentability that drags the city down the list quite a bit.

We don’t believe this is a make-or-break per se, but something to keep in mind if building an ADU for rent in El Cajon. With a market as strong and cyclical as El Cajon’s, ADUs are worthwhile.

Total ADU Friendliness Score: 27/50

Santee

A solidly “by-the-book” jurisdiction, the East County city of Santee follows state laws and provides a streamlined path for homeowners looking to build ADUs. Not much is offered beyond that, though. 

Santee ADU Development Accessibility

The City of Santee is not going to hold your hand through building an ADU, but that doesn’t mean it’s not possible. Here’s the gist:

• No ADU incentives or pre-approved ADU plans.
• ADUs in Santee can be up to 18ft high, a couple feet higher than the norm.
• The city’s ADU web page technically exists? But is uh…lacking. 

ADU Accessibility Score: 13/25

Santee ADU Rental Accessibility

An ADU in Santee isn’t as strong of an investment as in other parts of San Diego County. Here’s why:

• Santee has a weak rental market. 
• The ROI in this community is decent for a smaller size studio ADU, but pretty bad for a bigger size 3 bedroom. Build accordingly.

ADU Rentability Score: 13/25

Overall Santee ADU Friendliness

At a solid 26 out of 50, Santee toes the ADU-accessibility-line. If you asked us,

“Do you think building an ADU in Santee is a good idea or should we look elsewhere?”

We would say,

“Yes…”

The building process should be easy with the right people helping you. Using your ADU for rent in Santee isn’t as ideal, but still possible if you start with realistic expectations.

Total ADU Friendliness Score: 26/50

Vista

Generally considered ADU-friendly, Vista makes some strides to go beyond state minimum requirements in terms of encouraging ADU development, while also being significantly more limiting than other towns in the county. It’s an interesting mix. 

Vista ADU Development Accessibility

Vista offers some incentives and assistance for those looking to build an ADU, with limits:

• While state law (SB 13) already waives impact fees for units under 750 sq. ft., Vista extends these waivers to units over 750 sq. ft. if they are deed-restricted for low-income tenants or dedicated caregivers for at least 10 years.
• Pre-approved plans are available, and a decently comprehensive FAQ sheet is available online through the city. 
• Only one ADU (of any size, including a JADU) is allowed in Vista. 
• The planning department is not the most digital-friendly–paper plans must be delivered in-person for building an ADU in Vista.

ADU Accessibility Score: 13/25

Vista ADU Rental Accessibility

Renting an ADU in Vista can be a savvy investment because:

• Another strong rental market means owners shouldn’t have to deal with vacancies much. 
• The ROI could be better, but it could be much worse too–22% on average for a studio unit, which is on the lower end compared to the rest of the county.
• Average rent stays between $2k and $3k throughout most of Vista.

ADU Rentability Score: 13/25

Overall Vista ADU Friendliness

If you ask us, Vista could easily be much higher on this list. It’s very rentable and mostly ADU accessible.

The main things going against Vista’s overall ADU friendliness are how they only allow one ADU per lot and their comparatively low ROI for ADU rentals. This is the sole reason we placed Vista below Santee, despite having the exact same scores, as that’s a pretty big blow against ADU friendliness.

Only building one ADU for multigenerational living? Building an ADU in Vista will be a snap.

Total ADU Friendliness Score: 26/50

Lemon Grove

Next, we have the lovely inland town of Lemon Grove. State mandates are followed here but beyond that, Lemon Grove is more notable for its “civic icon,” a giant 3,000-pound lemon statue–which is admittedly really cool but unfortunately you can’t live in it!

Lemon Grove ADU Development Accessibility

Lemon Grove has limited accessibility for those looking to build an ADU. Note that: 

• With no ADU incentives or pre-approved plans, Lemon Grove doesn’t do much to especially welcome ADUs. 
• There isn’t a way to submit an ADU permit application online, you have to do it in person.
• Lemon Grove lacks comprehensive ADU information online, but does offer a two-page pdf of some standards to get started with. 

ADU Accessibility Score: 13/25

Lemon Grove ADU Rental Accessibility

An ADU in Lemon Grove isn’t exactly a money tree in the back yard. As an investment, be aware that: 

• The rental market is just okay. Many people opt for single family homes here, or townhouses / condos in gated communities. 
• Building an ADU in Lemon Grove won’t bring a big ROI, with rents here being the lowest in the county.
• You’ll get a better ROI for smaller units.

ADU Rentability Score: 10/25

Overall Lemon Grove ADU Friendliness

Aside from the city’s lack of outward (and helpful) acceptance of ADU development, ADU accessibility in Lemon Grove is mostly straightforward. They’re not making any waves, for better or worse. And that’s totally fine.

If your goal is to add Lemon Grove ADUs to your rental portfolio, we’d consider looking into other surrounding cities first. It won’t put you under, but you’d either make more elsewhere or take you slightly longer to break even.

Lemon Grove gets our approval, though we know they can add a bit more zest to their ADU acceptance.

Total ADU Friendliness Score: 23/50

Escondido

Last and we must admit least, we have the hidden city of Escondido (which literally means “hidden” in Spanish). This North County city of 150,000 mixes urban and suburban-type development, which you’d think is perfect for ADUs, though while it follows ADU state mandates, there are some stricter restrictions than its neighbors.

Escondido ADU Development Accessibility

In a couple important ways Escondido is less favorable to building an ADU than other parts of the county. Be aware:

• Escondido does not have any grants or financial incentives for building an ADU, but it does offer pre-approved plans that can save time and money. 
• The max square footage allowed is only 1,000 square feet–smaller than in the rest of the county. 
• In all other aspects, Esco follows in line with the state’s guidelines, even offering a very user-friendly website with a wealth of information just clicks away.

ADU Accessibility Score: 13/25

Escondido ADU Rental Accessibility

Renting an ADU here can be a mixed bag, here’s why:

• Escondido has one of the stronger rental markets in the county. Finding renters shouldn’t be hard.
• Still, the ROI here is sub-par. For studio ADUs it’s just 20% on average.
• The only unit size contributing to its higher rentability score is 3 bedrooms, which if we’re being honest, isn’t the go-to size for ADU rentals in Escondido.

ADU Rentability Score: 10/25

Overall Escondido ADU Friendliness

Sharing the same scores with Lemon Grove, we put Escondido at the bottom due to their smaller maximum ADU sizes and less-than-desireable ROIs per unit size. That isn’t to say Escondido isn’t worth looking into for building ADUs, though.

Despite placing “last” on our list, this is simply due to other cities excelling in either different or more categories, but Escondido is still relatively ADU friendly, especially compared to the rest of the nation (which we will slloooowwly make our way to…).

With the right plan, expectations, and execution, Escondido can be a great city to own an ADU (or two).

ADUs in San Diego County

Building an ADU in San Diego County is a no-brainer. Sure, there are cities requiring a bit more brain-work and strategy, but overall, San Diego is incredibly friendly to ADUs.

If you’re building for multigenerational living, increasing property value, or extra space, you will have the best experience in San Diego and La Mesa. The least desirable city to build in would be Coronado, with every other city falling somewhere in the middle, most likely giving you a very average experience.

Now, if you’re renting out your ADU in San Diego County, you’ll get the biggest bang for your buck in Coronado, oddly enough. Right behind that is San Diego, Del Mar, San Marcos, and Solana Beach. El Cajon, Escondido, and Lemon Grove will take the longest to get your money back, though it’s still very feasible.

Whether your plan is to build for personal reasons or to rent out an ADU, there’s almost no going wrong. With the proper due diligence, building and owning an ADU in San Diego will be a rewarding experience.

Methodology

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