Everything to Consider When Designing San Jose ADUs

Whether you call them granny flats, in-law suites, or backyard homes, accessory dwelling units (ADUs) are growing in popularity in California cities, including San Jose. The number of ADU permits across the state more than doubled from 2018 to 2019, not to mention the surge in ADU development accompanying the cultural shifts brought on by the onset of COVID-19.

Housing demand is outpacing the construction of new homes in job-rich areas like San Jose. This lag in supply is pushing housing costs higher.

In San Jose ADUs are filling the gap. They offer more affordable housing, extra income for homeowners, and keep extended families together. 

When planning your ADU, there are several things you should consider.

Consider Why You’re Building an ADU

Your goals for your ADU will help you determine a lot of the design factors. Those might include the dwelling unit size, special features, privacy considerations, and how much you are willing to invest.

The first consideration is who will be living in your ADU? Will it be a rental property or a home for your parents? Do mom and dad have physical limitations that you need to consider? 

How many people will be living in your ADU? Dwelling size for San Jose ADUs can vary from a few hundred square feet to upwards of 1,200 square feet (though these are rare)They can be studios, one, or two-bedroom units. How much space will you need for the number of people living there? 

Privacy is another consideration. If you’re building your ADU for family, privacy is probably less of a concern. But if your ADU is a rental unit, you’ll want to create a sense of separation for your tenant’s privacy and yours. 

Municipal Rules for San Jose ADUs

Make sure your lot is eligible to build on. ADUs in San Jose come in various shapes, sizes, and styles. Options include attached ADUs, detached ADUs, and existing structure conversions, like garage conversions. The city has pre-approved plans from some ADU builders.

Each type of accessory dwelling unit comes with limitations on size, height, and occupancy. The rules have recently changed, allowing more flexibility in designing and building ADUs in San Jose, including now allowing some two-bath units.

State lawmakers standardized rules regarding setbacks and easements. But ADUs in San Jose still need to be at least four feet from your property lines. And you’ll need to consider site access for emergency responders. Plus, the ADU occupant will need an unobstructed path to the street in case of fire.

Keep in mind that smaller ADUs offer some cost savings over larger units. They are generally less expensive to build, and under California state law, units less than 750 sq. ft. are not subject to impact fees such as parkland and school fees. 

ADU Parking Requirements

San Jose ADUs are subject to the same parking requirements as ADUs in other parts of California. And many San Jose ADUs qualify for parking requirement exemptions. 

New ADUs in San Jose need additional parking unless the property qualifies for an exemption under state law. No parking is required if the ADU sits within a half-mile of a public transit stop, is inside the primary residence, or an existing garage or other structure that’s been converted.

Other exceptions include ADU’s on streets requiring parking permits when the ADU occupant won’t be offered a permit. An ADU within a block of a car-share vehicle and those located in a historic district are also not required to add parking.

As of December 2019, replacement parking for garages and carports converted to ADUs are no longer required.

ADU Design Considerations

Are you planning to build an attached, detached, or internal unit (Junior ADU)? Each type has unique advantages and considerations, including available building space, unit size, construction cost, and space available. 

A detached ADU is a permanent structure that stands separate from the primary home. It’s a complete home with a kitchen, bath, living space, and sleeping space. Larger than a tiny home, detached ADUs are cottages that offer residents more space and privacy than other options.  

An attached ADU is well suited for a property that isn’t quite large enough to accommodate a detached structure. It’s still a complete, self-contained home with a kitchen, living space, and sleeping space. Attached ADUs have the advantage of a separate entrance from the main house, offering extra privacy.

A Junior ADU is a separate housing unit created within your existing home. They’re often attic, basement, or garage conversions. Junior ADUs frequently share entrances and other portions of your home with you. They can be a good option for a family member who needs extra care and a sense of independence.

You must also consider site conditions when developing your dwelling unit design ideas. Issues like slopes, drainage, trees, easements, plumbing, utility lines, and fire codes can significantly impact the kind of ADU you can have built.

Your personal preferences are vital to choosing the right ADU design for your needs. An experienced ADU building company understands the impacts of climate, building codes, planned use, and other factors that affect design choices.

Maximizing Your Budget

Setting your ADU construction budget will have an impact on all aspects of your project. The type of ADU you build and the quality of finishes used will greatly affect your construction budget.

Construction costs for San Jose ADUs can vary widely depending on the type of ADU you build. Converting existing space in the primary dwelling or a garage is less expensive than building a new, detached structure. But a new structure gives you more flexibility and design options.

If you build ADUs in San Jose that you plan to use as rental units, you will need to consider how much of a return on investment (ROI) you can expect and how long it will take to generate.

Working with an experienced builder that specializes in ADU construction can save you money. Your ADU building company should have a clear understanding of your needs, your budget constraints, and San Jose’s building regulations and permit process. 

Find the Right Builder

When you’re ready to build an ADU, you’ll want an ADU building company you can trust to get the job done right.

Acton ADU specializes in building San Jose ADUs. We’ve been residential builders for more than 30 years. We offer the most pre-approved ADU options in San Jose. Our end-to-end approach streamlines the process, saving you time and money, without sacrificing quality.Acton ADU can develop dwelling unit design ideas that fit your goals and budget. We’ll work with you from start to finish, so there are no surprises. Contact Acton ADU today and see what we can build for you.