The Alameda Planning Department has recently published new Alameda ADU requirements in the City.
One way they’ve done this is by allowing accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs) on single-family lots.
These small homes can be used as rentals or second residences, which helps homeowners recoup some of their costs while providing affordable housing options for others.
For all the information you require on constructing an ADU or JADU in Alameda, see our guide below.
These tips help you understand Alameda ADU requirements and rules to help you get started with building your accessory dwelling unit.
According to Alameda ADU rules, you’ll want to make sure you choose an ADU location that meets all of the City’s restrictions and Alameda ADU requirements.
Proximity to other buildings: The building must be at least 20 feet from any different structure on a property, including other buildings and accessory structures like garages, sheds, or even tree houses (yes, the City of Alameda does allow tree houses).
Location on property: You may build an ADU up to 10% of your lot size in either dimension—in other words, if you have a 10′ x 100′ lot, you could build a 1-story structure that measure up to 10′ x 10′.
Suppose your lot size is more than 50% paved or otherwise unsuitable for construction (like being located on top of a hill). You can still build an ADU, but only under limited circumstances and with advanced approval from your local government officials.
Location in relation to neighboring properties: Your new home shouldn’t be visible from any neighbor’s home by more than 25 feet at its closest point if they’re 400 feet away from it.
According to Alameda ADU rules, the minimum lot size for a single-family home is 7,500 square feet. If your property is smaller than this, you will need to purchase additional land to build on.
The Alameda Planning Department also requires that the ADU be on what they call “tightly zoned” land—meaning it must be in an R-1 zone or higher (residential) zone.
This means that an ADU could technically be built on any parcel of Alameda that has not been rezoned as commercial or industrial property by the City Council.
You may build an accessory dwelling unit or junior accessory dwelling unit above one of your existing single-family houses (or duplexes), but only if you own both homes and live in both at different times during the year.
You cannot rent out this second dwelling unit because it won’t meet Code requirements for being habitable if you aren’t there most days. Even then, you would still have to get special permission from the Planning Commission before building anything over your garage.
According to Alameda ADU requirements, the maximum number of ADUs allowed on a single lot is two ADUs.
The number of units is not constrained that can be built on a lot; however, there is maximum square footage for each unit and all units combined.
For example, suppose you have a 1,000-square-foot lot and want to build two 800-square-foot houses with decks and patios that total 4,000 square feet. Your application will be denied unless it qualifies under another exception or exclusion (more on later).
Properties with larger lots can have more units—a 3,000 square foot lot can house up to five 800 square foot houses with decks and patios totaling 5,600 cubic feet (or 6 bedrooms).
In Alameda, ADUs and JADUs have duplicate maximum square footage. The total size is 1200 sq. ft., which includes the garage. To calculate this area, you need to include any common areas shared between your main house and your ADU (such as hallways or staircases) but not those within the detached unit itself.
So what happens if you want to build something larger? For example, say you have a 1500 sq.-ft parcel of land in Alameda with one carport; could we build an ADU/JADU there?
No problem! Exceptions can be made by planning commissioners for more significant buildings—it’s all about finding creative solutions in unique situations. One such example is when someone wanted to put an accessory apartment over their garage and was granted permission.
According to Alameda ADU requirements, the maximum height for a detached ADU is 45 feet.
There are exceptions for second stories on two-story buildings and townhouses.
Setbacks are the minimum distance from a property line.
Setbacks are measured from the edge of the property line, or setback line, to the edge of an ADU. As such, they vary depending on what type of building you’re looking at: sheds and single-family homes have 10-foot setbacks; duplex units have 20 feet; triplexes have 30 feet, and buildings with more than three dwelling units have 40-foot setbacks (with certain exceptions).
It’s crucial to remember that these are only the minimum requirements — some lots will be allowed a variance if necessary for certain buildings (such as those built over time) or for aesthetic reasons.
According to Alameda ADU requirements, Parking depends on the type of ADU. An ADU no more significant than1,200 square feet is not required to have off-street Parking.
However, an ADU bigger than 1,200 square feet must have one off-street parking space for every four bedrooms or a fraction thereof (e.g., a two-bedroom ADU with one bathroom would require two off-street parking spaces).
The property line requirement means that your new addition can’t extend farther than ten feet from the property line.
This rule also applies if you are building a detached accessory dwelling unit (DADU), an additional living unit built in conjunction with a single-family home or duplex, and no more than 300 square feet in size (this does not include garage conversions).
Lastly, adequate street parking means that there must be enough space for all vehicles associated with the home(s) on the block to park safely at any given time without impeding traffic flow or causing issues for pedestrians.
We hope you have a good idea after reading this information of what to expect when building your Alameda ADU.
If you’re considering building one, we urge you to get started as soon as possible because there are many rules and regulations involved.
Also, if nothing else works or you need some advice on how best to proceed with your plans at Done Right Home Remodeling, we’re always here for help.
