More and more, we are seeing our clients with large lots, unused living space, oversized garages, or scarcely used attic space opting to build what is known within the construction industry as an Accessory Dwelling Unit or ADU. Why? The answer is simple. Given today’s housing shortage and the high costs of homeownership, many California homeowners have come to the conclusion that an ADU is a smart way to leverage their existing property investment by increasing its value and resale marketability.

Our clients are choosing to build an ADU for a variety of reasons. Some, with aging parents, realize that their loved one is no longer able to live entirely on their own, so more affordable and accessible alternatives need to be sourced. Constructing an ADU for Mom or Dad has proven to be the perfect option. For others with adult children who cannot find affordable housing, moving back home is a preferred choice provided Mom and Dad have the living or lot space available to accommodate their adult child.

In both these instances, separate but adjacent living space is desirable such that anyone who will be occupying the ADU gets to enjoy a level of independence and privacy while still being a part of the family and residing on or in the same property.

If you are unfamiliar with the term, put simply, an “ADU” is a secondary housing unit typically built on a single-family residential lot. Although it is possible for an ADU to be built in a multi-family residence, such as a duplex, triplex, or fourplex.

In the past, people have referred to what amounts to an ADU as an in-law cottage, granny flat, garage conversion, or backyard unit. Today, the standard term for such “housing” is Accessory Dwelling Unit, or ADU for short. If you’d like to learn more about how California defines an ADU, as well as the acceptable types, then click here. <hyperlink to the free PDF ADU Guide – name and email address required for download>

What are a Homeowner’s ADU Options?

An ADU can be a free-standing unit placed on the same lot as the primary residence, provided the lot size can accommodate such construction and local zoning codes allow it. However, an ADU can vary significantly. It can be a detached unit, or exist within a converted garage, basement, or attic. Alternatively, it can also be something referred to as a “bump out” which amounts to a new addition to the existing home that benefits from shared walls as well as easier access to utilities.

Sometimes referred to as a DADU, Detached Accessory Dwelling Units are new construction of a separate housing unit on the lot of the existing (and primary) residence. They vary widely in terms of design and style, although the total dimensions do have some very specific limits.

Per California ADU guidelines, depending on local code, your ADU can be up to 1200 square feet when detached. If attached to your existing residence, your ADU cannot be bigger than 50% of your primary home’s square footage.

When considering construction of an ADU, it’s important to avoid problems, as many can, and do, arise. It is strongly suggested that you work with a ADU-savvy general contractor such as Ed Neir Construction, or that you make the time to thoroughly check your local building codes regarding ADU guidelines. It is vital to either work with an expert general contractor or to do your homework because the range of municipal land use and zoning regulations that differentiate ADU types and styles, as well as their allowed use, do vary from city to city and county to county.

For those thinking about leveraging under-used and existing space “within” their residence, rather than opting for a detached unit, a Junior Accessory Dwelling Unit, or JADU, is a sound option.

In California, a JADU is a separate dwelling unit of up to 500 square feet, with a separate entrance from the main residence. It shares central systems, contains a basic kitchen that utilizes small plug-in appliances, and a JADU may share a bathroom with the primary residence. JADUs repurpose existing space within the primary residence without expanding the home’s planned occupancy. At Ed Neir Construction, we always check local building codes for our clients given that regulations, conditions, and restrictions can and do vary significantly with respect to city and county jurisdictions.

The Best Source for ADU Ordinances

The California Department on Housing and Community Develop (HCD) is the best source for information on local ADU ordinances. The numbers of ADUs has grown exponentially given they provide a great solution to the problem of affordable housing. In 2024, it is estimated that permitted ADUs numbered over 25,000.

The growing demand for ADUs is easy to understand. Unlike traditional commercial housing, an ADU doesn’t require purchasing land or investing in major new infrastructure. And, with an ADU, there’s no need to worry about structured parking or elevators.

As with any new construction, building your ADU with permits is crucial! Permitted construction ensures adherence to local building codes, allows for proper inspections, avoids potential legal issues, protects your property value, and enables you to legally collect rent for your ADU, when this is desired.

Working with your general contractor to procure all the necessary ADU building permits helps to ensure your peace of mind. It will also help you to avoid potential fines from authorities that are incurred without the proper permits.

If you are considering an ADU for a loved one or to generate passive income, it is wise to contract with an experienced, licensed general who fully understands and can advise you all along the way. Fully bonded, licensed, and insured, my team and I at Ed Neir Construction have been providing reliable construction excellence since 2009. With me as your general contractor and project manager, you’ll always have a highly-skilled and fully-accountable owner of the company working directly with you to meet your unique design style requirements and aesthetic specifications. My team and I will work diligently to ensure that your express needs and wants are clearly understood and that the vision for your ADU or JADU project is achieved, both on time and in budget.

Give us a call today to arrange for an appointment. I will visit with you to assess your property, and then work transparently to provide you with the best advice and latest ADU information appropriate to your city and county. As a follow-up to our meeting and a walk through of your property, I will deliver a free estimate of work and support your needs from early architectural design to final construction.

If you’d like to learn more, check out our blog titled, “Three Great Reasons Homeowners Are Building an ADU.” <link to this blog>

Warm regards,

Ed Neir & Team