Can ADUs Create a More Sustainable California?

ADUs are both a great housing option and a path towards improving the overall sustainability of California.



ADUs (accessory dwelling units) have been growing in popularity recently, and for many good reasons. They are affordable, financially profitable, and require no new land development. They create badly needed space for homeowners and create the opportunity for new passive income. And even more so, they are an essential part of the solution to the California Housing Crisis.



If that wasn’t enough, there’s another compelling reason why it is so vital to build ADUs in our neighborhoods: the environment. Housing is a significant driver of how we consume resources and live in harmony (or disharmony) with the natural world. As our environmental problems grow around the world, we must examine what housing choices we make as individuals, and how they affect the broader collective. There are a lot of misconceptions about how density impacts things like the environment, or traffic. The Urban Land Institute addresses a few of them, bringing up that building on existing urban infrastructure (Bus lines, roadways, shared parking spaces) reduces the need for new development. Because they're built in existing networks, ADUs are an incredible resource at our disposal if we want to mitigate climate change.



ADUs are second units built on an existing residential property. Think garage conversions and backyard apartments. They are also commonly known as granny flats, casitas, in-law units, and a whole range of other names. The laws around ADUs recently changed in California, and it is now much easier to build one on your residential property.



Are you eligible to build an ADU? Find out now with Housable’s free property check tool.

Sprawl Vs. Urbanization



California's housing market has historically grown through sprawl. We built sub-developments and single-family homes more than we built dense urban centers. Just look at the way that Los Angeles has expanded outwards over the years, from a tiny pueblo in 1877 to a metro area that extends over 4900 square miles.



Check out this visualization showing the expansion of Los Angeles overtime by NYU’s Stern Urbanization Project:

What’s wrong with sprawl? A couple of things:



Sprawl is inefficient

Sprawl inevitably means the construction of more single-family neighborhoods. While single-family homes are great, we also need to recognize that not everyone should be, or wants to be, living in them. Multifamily properties use 30% less energy than single-family homes and cost 50% less in terms of energy costs per capita. If we want to get serious about reducing our energy consumption and CO2 emissions, we need to consider more efficient housing solutions.



Sprawl causes traffic and pollution.



Even when people live far away from the city in a single-family neighborhood, they often still drive to work in the city center. Any Californian can testify to the many cars that clog the highways and lead to long commute times.



2. New sprawl requires developing new land.



Building a new sub-development requires constructing on previously untouched land, potentially threatening sensitive wildlife. So if sprawl doesn’t work, what is the alternative solution if we want to house our population? We need to consider urbanization as the more sustainable route to keep up with population demand.

When you hear the word urbanization, you might be thinking of New York City or big cities in Asia. But have no fear. There is a way to urbanize that will protect the integrity of your residential neighborhood while solving the broader housing problems and protecting the planet.



Garages and Backyards



If we’re not going to build outwards, what other options do we have? After all, the California population continues to grow every year, and we need to address the cost of living by adding additional supply.

First, we need to see an increase in intelligent multifamily development. This doesn't mean bulldozing neighborhoods and turning them into skyscrapers; what it does mean is taking vacant warehouses and turning them into comfortable apartments.

Second, we need to consider what other space is available but not being used. Single-family homes across the state have additional space that could be housing people and generating rental income. Single-family units make up 56.4% of housing stock in California , and 60% in large metro regions like San Francisco and Los Angeles.



ADUs still make up a tiny fraction of existing housing stockand new development. The vast majority of California single-family homes are simply not operating at their potential - missing out on the opportunity to generate new rental income and home appreciation.



All of those empty garages, basements, and backyards? Those could be turned into beautiful new units - going to work for the property owners and housing many new people. The evidence above demonstrates why ADUs are so important. They preserve the integrity of the neighborhood and house more people, all while benefiting the bank accounts of the property owners, and keeping rent prices manageable for the state.

ADUs as the Environmentally-Friendly Housing Solution



ADUs are small, sleek, standalone units that homeowners add to residential properties. They connect to utilities and consume power and water like a standard home or apartment.



ADUs have fewer rooms compared to normal houses, which translates into a lower electricity bill. They have reduced physical footprints and require fewer construction materials. In the case of garage and basement apartments, no new structure is required.



ADU residents, on average, have a lower per capita resource consumption. Also, the carrying capacity of the entire household increases, which decreases the resource consumption per person of the whole property.



Then, ADUs can include the most energy-efficient appliances possible. If you build a detached structure, you can even add solars panels on the roof. Many Californians care about the environment but struggle to find ways to make a difference. As we learn that recycling programs may never have been as sustainable as we thought, citizens are looking for new ways to live sustainably.



With ADUs, it’s a win-win-win. Positive financial return, solution to the housing crisis, environmental benefit.



California needs to add more ADUs as quickly as possible.



Are you considering an ADU for your property? Find out whether you are eligible to add an ADU on your property by using Housable’s free property check tool.