San Jose ADU Regulations

Building an ADU in accordance with the San Jose ADU regulations has become very common today. This is because recent events have shown the value of keeping families intact. In the US today, one in four households has multiple generations living together. In the last ten years, this has increased by 15%!

Adding an ADU to your home could be a great solution if you live in the San José region. The construction of backyard residences is part of the San José Mayor’s commitment to increasing the local housing supply.

To learn more about adding an ADU to your home, let’s look at the San Jose ADU regulations.

San Jose ADU Regulations – All Details

The City of San José has created a San Jose ADU checklist. This combines the San Jose Municipal Code with state laws to add an ADU in California.

Any owner or developer thinking of including an ADU on an existing or newly built property should start here.

It includes the following areas:

• Qualifying properties
• Property designations
• Development standards
• Fire safety and emergency access
• Miscellaneous

Before creating construction plans, it is important to complete the checklist. This will help you determine if your ADU project is likely to receive the permit. Let’s talk about some of the aforementioned points:

Qualified Properties

For the ADU building to be feasible, your property must be in the right neighborhood and zone. Find out by contacting the San Jose Permit Office whether:

•  The City of San José has jurisdiction over your property.
• Your property is within a residential zone beginning with R-1, R-2, R-M, or PD

Other General Plan designations also allow for ADU construction, including:

• Residential neighborhoods
• Commercial mixed-Use or Mixed-Use Business Neighborhoods
• Urban residential/transit residential/rural residential neighborhoods
• Downtown or Urban Village

You cannot build an ADU on your property if your home is not within one of these zones. Talk to a San Jose City Planner if you’re still unsure about your home designation.

An ADU can be built in a single-family home. In duplex or multi-family homes, two detached ADUs may be allowed.

On a multi-family lot, it is possible to build multiple ADUs. For example, a building with 8 units may be allowed to build 2 ADUs, since the current rate is set at 25% of existing units.

Development Rules

In addition to complying with ADU zoning guidance, all ADUs in San José must comply with development rules.

These differ depending on the design of your house.

Single-Family Homes

The rules regarding single-family homes are as follows:-

• An attached ADU must share a wall or roof structure with the primary residence.
• An attached ADU cannot have its front door on the same street frontage as the primary residence.
• A detached ADU must be in the backyard or 45 feet from the front property line.
• Must have a 6-foot separation from the main house
• Can be converted from an existing detached garage or accessory building.

Duplex And Multi-Family Homes

The rules regarding duplex and multi-family homes are as follows:-

• Conversion of an existing office, basement, garage, or attic is required to create attached ADUs.
• Detached ADUs must be 45 feet from the front property line or in the backyard.
• Must have a 6-foot separation from the main house

Size And Height Restrictions:

The size of the lot and the allowable backyard coverage determine the size of an ADU.

The backyard, measured from the property’s rear to the rear boundary, cannot have more than 800 square feet (or 40%) of its area covered by structures.

The ADU sizes allowed on single-family lots are:

• Lots up to 9,000 square feet:
• Detached ADU: 1000 sq. ft. maximum
• Attached ADU: up to 800 square feet or 50% of the area of ​​a principal residence, but not more than 1,000 square feet
• Lots 9,000 square feet or more:
• Detached ADU: 1200 sq. ft. maximum
• Attached ADU: up to 800 square feet or 50% of the area of ​​a principal residence, but not more than 1,200 square feet

If a lot already has an existing JADU, a detached ADU of up to 800 square feet is allowed. You cannot include an attached ADU if the home already has a JADU.

ADUs can be attached or detached and cannot exceed 800 square feet on duplex and multi-family sites.

Setback Prerequisites

For single-family homes, attached ADUs have minimum setback restrictions. The requirements match the primary dwelling unit in every way.

Attached ADUs cannot be built on existing duplexes and multi-family homes, so there are no setback requirements.

For a single-family home, a detached ADU must:

• Stay at least 45 feet from the front line of the property.
• Have rear and side setbacks of a minimum of 3 feet, or comply with fire mitigation measures.
• Two-story or new ADU with more than 40% yard coverage must be 4 feet from the back and sidelines of the property

For a duplex or multi-family property, a detached ADU must be:

• Located in the backyard or must be 45 feet from the front property line
• Side and rear setbacks of a minimum of 4 feet
• A second floor is not allowed.

There are many San Jose ADU requirements that homeowners must adhere to. But rest assured, the city supports the efforts of the people to increase the current housing stock in this way.

If all of this seems overwhelming, the easiest option is to work with a reputable ADU contractor like Goodman Home Remodeling, who has the experience and knowledge to make things simple for you.