A guide for building backyard homes in

Berkeley, California

You can build an ADU in the city of Berkeley so long as your property is in a residential zone and the ADU you build is within the statewide ADU standards of 800 square feet, with a height limitation of 16 feet and and 4 feet rear and side yard setbacks. The number of ADUs you can build and the height & sizing requirements depend on factors specific to your property. These can be found in the answers to the questions below.

You need to receive an approved building permit in order to build an ADU or JADU in Berkeley. Compliance with the ADU zoning and development standards is reviewed as part of the building permit process.

At Type Five, we take care of your entire permit process saving you time, money, and energy.

The maximum amount of time the city of Berkeley has to review your permit application is within 60 days of submission. It is possible to get your permit approved within 30-90 days of submission so long as your designs were drawn with the local code in mind.

At Type Five, we take care of your entire permit process. Our ADU plans meet the highest standards of construction and building code across California, ensuring that our permits are approved in the shortest time possible.

The number of ADUs you can have in Berkeley depends on whether or not your lot has a single-family dwelling (and the amount of single-family dwellings on the lot) or has a duplex or multiple-family dwelling on the lot.If you have a lot with one single family dwelling you are allowed 1 ADU and 1 JADU.

If you have a lot with more than one single family dwelling you are allowed 1 ADU and no JADUs.

If you have a lot with a multi-family residence, you are allowed to have up to 2 ADUs.

There is no minimum lot size requirement for an ADU in Berkeley. California state law also mentions that lot coverage requirements can’t preclude the creation of a statewide exemption ADU. A statewide exemption ADU is 800 square feet, with a height limitation of 16 feet and and 4 feet rear and side yard setbacks.

With Type Five, you can design an ADU to fit whatever available space you have in your backyard. Our system can flex and adapt to ensure you can build high-quality livable space even if it's in a smaller area. Get started with designing your ADU here.

There is no minimum size for building an ADU in Berkeley. California state law gives local governments the ability to set minimum and maximum height standards. However they cannot require a minimum square footage requirement that prohibits an efficiency unit.

Type Five's ADUs can adapt to a variety of different sizes for your need. Get started with designing yours here.

The maximum size for building an ADU in Berkeley is 850 square feet for a 1 bedroom ADU and a maximum size of 1,000 square feet for a 2 bedroom ADU.

It depends on on your zoning. The city of Berkeley has different height requirements for certain areas.

If your zone is within the Hillside Overlay District, the city has a maximum height requirement of 16 feet for ADUs, which means that you cannot build a 2-story ADU in Berkeley. The state of California’s building code requires a 7 feet ceiling height requirement and when you factor in the height of space needed for the floor & roof, 16 feet is typically not enough to build a legal 2 story ADU.

If your zone is outside of the Hillside Overlay District, then the city of Berkeley has a maximum height requirement of 20 feet for ADUs which means that you can build a 2 story ADU in Berkeley.

Type Five offers two-story layouts that are designed to meet the 20 foot height restriction in Berkeley.

There is no limit to the number of bedrooms an ADU can have in the city of Berkeley according to California state law. The California HCD ADU handbook states that a limit on the number of bedrooms could be construed as a discriminatory practice towards protected classes, such as familial status, and would be considered a constraint on the development of ADUs.

All ADUs built in Berkeley and the state of California are required to have 4 feet side and rear yard setbacks. State law allows for a local government to determine its own front yard setback requirements. Berkeley requires a front yard setback of 20 feet.

A local agency, special district, or water company in does not require an ADU to have its own electrical panel, water meter, or gas meter in the city of Berkeley, unless the ADU was built at the same time as a new single family dwelling on the property. However, owners of ADUs that plan to be used as rental units typically install a new set of utility meters to make billing cleaner for tenants.

You are not required to install fire sprinklers in an ADU in Berkeley so long as sprinklers are not required in your main residence.

You are required to install solar panels on your ADU in Berkeley if your ADU is a newly constructed, non-manufactured, detached ADU.

You should be able to rent an ADU in Berkeley for $3,164 which is the average monthly rent for a one bedroom apartment so long as the rental term is longer than 30 days. There is no owner-occupancy requirement for ADUs built prior to December 31st, 2024.

You cannot use an ADU as an AirBnB in Berkeley unless you are renting it out for a period longer than 30 days. California law states that ADUs created under subdivision (e) of Gov. Code, § 65852.2 cannot be rented for a period less than 30 days. This means you cannot use your ADU as a short-term rental in Berkeley.

Your local homeowners association (HOA) cannot prohibit the construction of an ADU or JADU in Berkeley. Assembly Bill 670 (2019) and AB 3182 (2020) amended Section 4751, 4740, and 4741 of the Civil Code to preclude common interest developments from prohibiting or unreasonably restricting the construction or use, including the renting or leasing of, an ADU on a lot zoned for single-family residential use.

Covenants, conditions and restrictions (CC&Rs) that either effectively prohibit or unreasonably restrict the construction or use of an ADU or JADU on such lots are void and unenforceable or may be liable for actual damages and payment of a civil penalty.

The city of Berkeley will assess the value of your newly added ADU, typically by using the cost-bases method of appraisal, and multiply it by the property tax rate of 1%. So if your ADU in Berkeley costs $217,053 to build, you can expect your annual property taxes to increase by $2,170.53 per year. Adding an ADU to your property will not trigger a reassessment of the value of your primary residence.

Adding an ADU to your property in Berkeley typically adds value to your property, however, the exact amount depends on the appraisal method that your appraiser chooses to use. If an appraiser uses the cost-basis method & the cost of your ADU is $217,053, then you can expect your home value to appreciate by $217,053.

Another method that an appraiser can use is the sales comparison approach, where the value of the ADU addition is determined by recently sold properties in Berkeley that included ADUs. However, this approach depends on the number of recently sold properties and there sometimes isn’t enough information to use this approach with ADUs. A back-of-the-envelope way to estimate the value yourself would be to multiply the existing price per square foot of your property by the square footage added by the ADU and compare it to the cost of your ADU. The appreciation is likely in between those two numbers.

The average cost to build an ADU in Berkeley is $217,053. Keep in mind there are a ton of factors to consider when estimating the cost of a project, many of which are unique to your property and sometimes require special surveys to identify. Examples of these factors include whether or not your property is flat or sloped and whether or not you need to upgrade your utilities.

It’s also important to note that converting an existing structure or converting your garage into an ADU isn’t necessarily cheaper than building a brand new detached ADU. You can get an in-depth overview about what goes into the costs of building an ADU in your city on our cost calculator page, or you can get a brief idea of what costs look like below.