ADUs are separate housing units built on existing single family residential properties. ADUs are also known as secondary dwelling units, guest houses, backyard cottages, mother-in-law units and granny flats.

Thousands of new ADUs are being built in communities across the US because they are a manageable and minimally disruptive option for adding desperately needed housing to existing neighborhoods. Moreover, ADUs typically cost less than other forms of housing and make efficient use of existing land. ADUs allow for people to age in place or form multigenerational households to ease caregiving responsibilities and cost.
Homeowners, given the high cost to buy a house, are frequently turning to ADUs to provide additional income to make ends meet. Lastly, the appeal of downsizing and minimalist living seems to be growing and ADUs allow people to simplify their lives and still live in a neighborhood setting.

ADU Forever sells fully installed ADUs in the California market starting in the mid price of $100,000's. This price includes all permits, installation costs, utility connections, appliances and landscaping. ADU Forever is one of the most affordable but high quality options for a detached ADU.
Because of the variability of site characteristics, ADU Forever fixed price will not cover the cost of removing existing structures, large trees, underground storage tanks and cesspools and other impediments to installing an ADU, nor will ADU Forever cover the cost of non-standard installations or utility connections, or upgrading utility service to a property to serve the ADU. In addition, impact fees can vary, these costs are passed through to the homeowner

We are responsible for all of these tasks, including design, permitting, construction and installation of the ADU. The fixed cost covered not only the cost of construction and installation, but also the cost of permitting, utility connections and landscaping.

Many different types of properties will accommodate an ADU. In most cases, properties with a flat backyard with few obstructions, and where an open space with minimum dimensions of 45′ x 25′ can be created, will work. If you aren't sure, contact us and we'll review property information online and even perform a site visit to determine if your property is suitable for an ADU.

The monthly rents for an ADU typically reflect neighborhood market rents. For example in San Jose, California rents for a single family ADU are roughly $2,500 to $3,000 per month.

The presence of an ADU can often enhance the attractiveness of a house on the market, and increasingly investments in new ADUs are being reflected in the appraised value of these properties.

The installation of any ADU will result in an increase in property taxes equal to the assessment of the ADU as an improvement to the property. The addition of an ADU should not result in a new assessment of the rest of the property. The homeowner's property tax bill can still increase as a result of standard annual increases in taxes and new levies that are added to property taxes each year unrelated to the ADU.

Yes. Many homeowners create ADUs so that they can benefit from the rental revenue it generates.
Alternatively, you can choose to keep the ADUs for visiting family and friends.

Yes. It's very common for homeowners who complete an ADU to use that new unit as their primary residence.
The previous living space can then be used for visitors or to generate rental income.

Cities and counties cannot consider ADUs as new residential uses when calculating connection fees and capacity charges.
Where ADUs are being created within an existing structure (primary or accessory), the city or county cannot require new or separate utility connections for the ADU and cannot charge any connection fee or capacity charge.
For other ADUs, a local agency may require separate utility connections between the primary dwelling and the ADU, but any connection fee or capacity charge must be proportionate to the impact of the ADU based on either its size or the number of plumbing fixtures.

With ADU Forever extensive development background, please call us for consultation on adding substantial value to your property.

Generally, you will be able to build at least a 1000 sqft ADU, and up to 1200 sqft in some cases. Read our guide to ADU size maximums and see city-by-city ADU regulations here.

New state laws permit two ADUs on a single family zoned property: one full Accessory Dwelling Unit (ADU) and one Junior Accessory Dwelling Unit (JADU). On multifamily properties, you can build up to two detached ADUs.

There are no minimum lot sizes for accessory dwelling units per California state code. Even if there is a coverage ratio maxed out on your property, you are still allowed to build at least an 800 sqft ADU.

Per state law, setbacks for new ADUs have been reduced to 4′ for side and rear yards. The City of San Diego went even further and has established 0′ setbacks on the side and rear yards for ADUs. Also, no setbacks are required if an existing and permitted accessory structure is being converted. You can even remove an existing structure (like an old garage) and replace it with a new ADU that matches the old footprint, even if the old structure had pre-existing reduced setbacks. Any new addition must comply with setbacks, with exception of up to a 30′ encroachment (e.g. above a garage that is at the lot line). Note that if you choose to build directly up to the setback, there is more of a risk that the city inspector may require a survey. To reduce this risk, we advise leaving an additional 18″ buffer on all required setbacks when possible. Some municipalities have minimum building setbacks, meaning the ADU must be a minimum distance from the primary residence; state guidance defers to local regulations in this case, and typical is 5 to 10 feet (though some cities do not list a minimum; fire code is still a consideration, which is why we usually hold at least 6′ from existing structures).

Yes, you can build an ADU in your front yard if it complies with underlying setbacks for your lot. However, the state laws have not reduced setbacks for the front yard, only for the sides and rear.

If your ADU is under 500 sqft, it will not require civil engineering review (stormwater, catch basins etc). If your ADU is under 750 sqft, you will not incur impact fees (except for the school fees which are still due even after the new regulations). Our standard 1BR and 2BR designs are under 500 sqft and 750 sqft to help you avoid those additional costs (typically $3-5K). Use our plan search to find floor plans at the size you want.

An ADU is a designation that can't exist by itself – there must also be a primary residence – so the initial home will be considered the primary residence. Then once you build the second larger home, you would then "convert" the status of the original building to an ADU. This means you would need to ensure the first structure you build (what you would later call the ADU) will conform to both the requirements for a primary dwelling AND the requirements for an ADU. Read more about if you can build an ADU before the main home.