By Sharon Simonson
Call it getting down to the nitty-gritty.
Before designing or submitting a permit application for an accessory dwelling unit (ADU), you should know about any constraints associated with your property. This is the first step to starting your ADU smart: Read the City’s online ADU information and do a bit of property research.
Of all the mistakes she sees with ADU project submittals, Sarah Shull – the City of San José’s ADU Ally – says the most avoidable arise from skipping research about the property, which for homeowners can lead to the frustrating discovery that their proposed ADU location or design is not allowed.
“I feel the pain for those applicants when the whole project is denied at submittal because of location issues,” said Shull, who spends her days helping homeowners navigate the ADU permit process. “We want to prevent that.”
Property Research & Draft Site Plan
Before everything else, success relies on knowing (1) if your property can accommodate an ADU, and (2) if yes, how it might be situated.
The answers to both “if” and “how” questions precede and determine any consideration of how big an ADU might be or whether its design should match that of the main house. While most single-family homes in San Jose are eligible for an ADU, there are property characteristics such as zoning, easements, flood zones, geologic hazard zones, and existing building configurations that affect an ADU’s overall size and where it might be situated.
At www.sanjoseca.gov/ADUs, the City puts this information at homeowners’ and designers’ fingertips so they can “start their ADU smart.”
The City’s ADU Universal Checklist, homeowner’s title documents, and public records found at SJPermits.org are resources that help determine if a property is eligible for an ADU and provide the information necessary for creating a simple site sketch to show where the ADU could be feasibly located.
By completing the ADU Universal Checklist, you will begin to understand ADU requirements that apply to your property. For example, if your property sits in certain flood zone or a geohazard zone, the ADU must be designed and built to specific standards for such zones. If clarification is needed, the checklist provides contact information to connect with department staff for more information.
The checklist also spells out the fire regulations that require a three-foot clearance around the perimeter of the ADU to enable access on all sides in the event of a fire. That means the ADU must be at least three feet from a property line or other structure as measured from the outer edge of eaves of the ADU. If you must build on a lot line, you may apply for a Fire Variance, and the Fire Department may offer alternative methods to ensure the safety of the ADU, such as building fire-rated walls and installing fire sprinklers.
After completing property research and the ADU Universal Checklist, the next step is to use this information as the basis for a simple site plan of your property and proposed ADU. This site plan sketch and the completed ADU Universal Checklist can be emailed to a City Planner at [email protected]. The Planner will review the concept for compliance with ADU zoning rules and provide basic design feedback. This is a free service to ADU applicants.
The site plan sketch should show the following information:
Creating Plans & Benefits of Preapproved Plans
The next step after getting a City Planner’s input on your concept is creating detailed plans and a submittal package. According to Shull, the easiest and fastest way to add an ADU to your property is to opt for a preapproved ADU. At www.sanjoseca.gov/ADUs, you’ll find a list of vendors who offer preapproved plans for detached ADUs. These vendors understand the City’s ADU permit process, and their products have been reviewed and approved by the City in advance. They will also handle the research of property conditions such as easements and setbacks and identify where an ADU can be situated on your property.
If you want a custom-built ADU, Shull recommends that your hire a designer or licensed professional architect/engineer who has experience with ADU projects in San José. To anyone creating ADU plans, Shull says to always use the City’s online resources at www.sanjoseca.gov/ADU and specifically the ADU Plan Review and Permit Process webpage and the handout, Your Pathway to a Completed ADU.
People with an existing garage or office may want to convert these to an ADU. While the notion might make intuitive sense, it may introduce complications.
If the existing structure is old, for example, it probably won’t meet current building codes and could necessitate expensive upgrades.
Garage conversions in particular present the challenge of turning uninhabitable space into habitable space, Shull says. You will likely need to add insulation, windows, and a vapor barrier for the floor.
Size is another issue and will affect the fees you pay. To avoid city parkland fees and public school fees, keep the ADU to 750 square feet or less. If you want to further minimize costs and pass through the city review process more easily, keep your ADU to 500 square feet or less.
“The larger you go means there is more building for us to review. Keep it small and simple,” Shull says. “ADUs of 500 square feet or less move through our plan review process the fastest.”
If your property is in a designated historic district or appears on the California Register of Historic Resources, an attached ADU – which entails the expense of a planning permit — must meet the historic design standards set for the house. See Your Old House for Historic ADU Requirements. A detached ADU, on the other hand, does not need to match the design of the main home.
Whatever you wind up proposing for your ADU, you’ll want to submit accurate and complete plans. Most often, ADU applicants go through two or three cycles of review due to plans being incomplete or not fully accurate. This again points to why you should work with ADU designers who are familiar with San José’s permit process or use a preapproved ADU design.
“We want to help you get your ADU plans approved in one or two cycles,” said Shull. “You can do it if you follow our ADU Universal Checklist, ADU Building Plan Requirements & Worksheet, Inspection Checklist for ADUs, and all other online resources.”
Shull likens submitting ADU plans to a final exam – “And the homework to pass the exam is following our ADU Universal Checklist and online resources,” said Shull.