San Jose, California, is one of the cities leading the way in addressing the affordable housing crisis through Accessory Dwelling Units (ADUs). In 2017, San Jose implemented new ADU rules to regulate the development of ADUs with the aim of fostering both the affordable housing stock and more reasonable and sustainable development within the city. They have facilitated construction of ADUs by the residents thus increasing housing stock for renters and homeowners.
This is important in order to know all the rules and conditions allowing to achieve the greatest results. This article encapsulates all that you would want to know about ADUs in San Jose, including size and setback restrictions, parking considerations, design requirements, permitting costs, and fees, and the lesser-known Junior Accessory Dwelling Units or JADUs.
In this comprehensive guide, you will find the key aspects of San Jose ADU ordinances and resources on how to build an ADU in the city. Now let’s look at the key legal compliance matters, permits necessary, and useful tips that will help to navigate through the laws needed for an ADU project as well as to organize it effectively.
San Jose recognizes two types of ADUs: attached and detached. Contractors build attached ADUs as additions to existing main houses, while they construct detached ADUs as separate structures on the same lot. San Jose ADU rules govern each type of ADU, with regulations influenced by factors such as lot size, location, and existing structures.
The maximum size of an ADU depends on the type of ADU and the size of the lot. The following table shows the full sizes of each ADU:
| ADU Type | Maximum size | |
| Attached ADU | Up to 800 square feet or 50% of the primary residence area, but at most 1,200 square feet. | These units are physically connected to the primary residence. |
| Detached ADU | 1,200 square feet. | These units are separate from the primary residence. |
| JADU | 500 square feet | These units are smaller than 500 square feet and are located within the footprint of the primary home. |
| THOW | 400 square feet | These units are allowed only on single-family properties and have different requirements and a more straightforward, lower-cost permit process. |
The maximum height of an ADU is generally 16 feet. However, there are some exceptions, such as for ADUs on lots with a slope greater than 20%.
When building accessory dwelling units (ADUs), it is essential to adhere to specific requirements. Precisely, setback regulations must be followed to ensure safety and compliance.
For instance, one is required to place an attached ADU not less than 4 feet from the side and rear boundaries of the property. Moreover, an off-site ADU should be a minimum of 4 feet from the side and rear lot lines and 5 feet from the front lot line. Moreover, JADUs need to have certain distances, in order to promote fire safety, which may be a problem.
Many other factors can affect the requirements for an ADU, such as the zoning of the property and the specific location of the ADU on the lot. It is essential to consult with the City of San Jose’s Planning Department to get particular information about the requirements for an ADU on your property.
An Accessory Dwelling Unit (ADU) must be architectonically integrated into the main residence and the neighborhood. Although there are no rules concerning the design of ADUs, the city has a few recommendations as to their construction, such as using the same materials and colors as in primary houses. It is important to maintain the standard of design for example when developing new buildings it should be looked at whether the current buildings around will complement the new ones.
This type of housing known as Accessory Dwelling Unit (ADU) requires a planning permit from the City of San Jose. It always takes upto two months for permitting process while the permit fee depends on the size and type of ADU to be constructed.
The first prerequisite to obtaining a permit is to apply for it with the City of San Jose. The form to apply for permit can be downloaded from the City website. The time required to perform the plan review averages within two to three weeks. At the time of plan review, the City will be conducting check on whether your ADU conforms with the local zoning as well as building regulations. This permit attracts a fee that you need to pay before you start construction of your ADU.
The permit fee for an ADU is based on the size and type of ADU you are building. The following table shows the permit fees for different types of ADUs:
| Type of ADU | Permit Fee |
| Detached ADU | $1,200 |
| Attached ADU | $600 |
| Junior Accessory Dwelling Unit (JADU) | $300 |
In addition to the permit fee, you may also need to pay other costs, such as school impact fees and parkland impact fees. The amount of these fees will vary depending on the size and location of your ADU.
In addition to ADUs, San Jose allows the construction of Junior Accessory Dwelling Units (JADUs). JADUs are smaller than ADUs, with a maximum size of 500 square feet. JADUs can be located within the footprint of an existing single-family home, such as a converted garage.
The permitting process for JADUs is more straightforward than for ADUs. You can obtain a JADU permit online, and the permit fee is significantly lower.
For more information on San Jose’s ADU and JADU regulations, please visit the city’s website.
When planning to build an ADU there are some factors that need consideration to enhance the success of the project. First of all, we should develop the ADU’s design that must be not only practical but also attractive. Such considerations include positioning of the layout so as to use as much of the space as possible, and selection of the materials that would last longer and where maintenance will not be a big deal, and on the design methodology; to go with a certain kind of style that complements the main building.
Also, the construction process should also adhere to the building codes of the city and the San Jose ADU regulations. This encompasses issues such the right installation of utilities in the building, compliance with the energy code, right specifications of access and safe exit.
Paying for an ADU can be quite a challenge, but there are numerous possibilities open to the homeowner. More common forms include conventional or home equity loans or even home equity lines of credit (HELOCs) whereby you will use the cash out of your existing property to finance the ADU. On the other hand, cash-out refinance entails a homeowner presenting his or her home as security for a new mortgage that he or she gets to pay for the ADU by cashing out the difference.
You can also include the personal and construction loans as future expansions but these attract higher interest rates. Several cities including San Jose has set aside loan programs for ADU with an aim of helping to ease the housing crisis. You may always can address a financial specialist or a consultant to study your situation to find out what financing product will suit you the most.
Thus San Jose homeowners have the ability to build an ADU that can be greatly valuable and fulfilling endeavor. As you conform to the guidelines of the city, and get the appropriate permits it would to the endeavor of making affordable houses even as you gain on your asset value. Some of the most important requirements to be followed should be fulfilled by experienced personnel only like Herman Remodeling as well as regulatory requirements and codes. If you would like to have a consultation on your ADU project, feel free to reach out to us and get going.
In San Jose, local zoning laws determine where ADUs can be built, the minimum lot size, and how large the ADU can be. These laws also dictate setbacks, height restrictions, and parking requirements, all of which must be adhered to during construction.
Yes, in San Jose, you can rent out your ADU, either as a long-term rental or for shorter stays, depending on the city’s regulations. However, the property owner must occupy either the main house or the ADU to comply with local laws.
In San Jose, the ADU approval process typically takes around 60 to 90 days, depending on the complexity of the project and how quickly required documents are submitted. The timeline may vary based on factors like zoning reviews and permit processing times.
