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What is an ADU?

ADU stands for Accessory Dwelling Unit. An ADU is also known as a granny-flat, mother-in-law-suite, backyard home, cottage, and casita. An ADU is fully functioning living space with a bathroom, sleeping area, and kitchen.

What is city ADU Zoning or Ordinance?

A city ordinance are the rules and laws for building an ADU. Zoning is a city’s primary tool for regulating development, determining the size, shape, style, location, and permitted use of buildings in a given area.

How much does and ADU cost?

There’s really no straight answer to this question without knowing more about your goals (short and long term) and the parameters surrounding your property. We need to weigh many factors and variables such as the location of the ADU on your property, if the existing infrastructure of your home will support an ADU, your design preferences, how big you want your ADU to be and how many rooms you need, the number of bathrooms, the level of finish materials, size of the kitchen and bathroom, if there’s a laundry room, and more.

Garage conversions may require a lot of work to make them livable even though the shell of the structure exists. Concrete slabs and foundations may need to be removed for power, sewer, and water, and require retrofitting the foundation.

Have realistic expectations about the costs. Some assume because they have a small home it will be cheaper to build; in fact it’s just the opposite due to the economy of scale and reasons mentioned above.

Many companies advertise low costs for an ADU just so you will contact them. Often the cost other companies advertised only includes the shell of the home (foundation, framing, roof, and windows).

As a ballpark budget, a detached ADU can cost upwards of $120,000 to design and build. An ADU conversion can cost upwards of $100,000, depending on the state of the current structure.

What is a detached ADU?

A detached accessory dwelling unit is a separate living space that is built separate to a primary residence and is not structurally connected.

What is a Junior ADU?

A JADU is a small living space no more than 500 square feet created out of a room within an existing single-family home, not a garage or other accessory building. It may include a bathroom and laundry room or share it with the primary residence.

How long does it take to build an ADU?

A garage or storage room conversion will take upwards of eight weeks to build. A detached ADU will take upwards of four months to build.

Can I build an ADU on my property?

If you own a single-family or multi-family property in California you can legally build an ADU, however you will have local ordinance requirements.

What size ADU can I put on my property?

An ADU can range in size between 150 - 1200 square feet, although the size of your home or multifamily building may be the determining factor.

Who does the work to obtain city approval of my ADU?

We facilitate city approval to address all the building and zoning requirements and permits.

Can you help me evaluate the return on investment of building and ADU?

Yes, an ADU is a long-term real estate investment best examined over a 15 to 30 year period. There is equity added to your property when remodeling, adding square footage, or building an ADU. If you plan to rent your ADU we will factor in the passive income.

We also factor what it’s costing you if you don’t build an ADU in the short-term and the long-term. Applying the savings of expenditures you or your family are paying for such as senior housing, childcare, student housing, office rental factor into the total costs of your investment.

Do ADUs increase my property taxes?

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 entire property.

How do ADUs affect the sale of my home?

Adding an ADU is a major investment into your property. An ADU can enhance the attractiveness of a house on the real estate market. The type of ADU, level of finish, the property location, and other factors will affect sales costs. We work with Realtors and appraisers who can help determine this value.

Can you help me remodel my home while you build an ADU?

Absolutely! We often will complete the ADU build first for you to live in while we remodel the main home second.

Can you design an ADU so I still have privacy in my current home?

Yes, retaining your privacy and quality of life is a top priority during the design process.

Do you sell and build factory manufactured/prefab ADUs?

Yes, we are partnered with a prefab ADU manufacturer, but this may not be the best option depending on the size, design, and location of your ADU. We most often build conventionally with stick framing and sometimes with trusses. This structural style has been time-tested and allows more flexibility in design and construction. Depending on the complexity, a prefab ADU typically shortens construction by a few weeks, but can take longer for city approval. Cost of building a prefab ADU is comparable to conventional stick framing. Alternatively, we find that our ready-made construction plans speed the design and construction process, are cost effective, utilize time tested construction techniques, and allow for more customization for you and your property..

What are ready-made construction plans?

Harding Construction has taken some of the guess work out of the equation to provide you with a turnkey solution to creating an ADU. We have curated a selection of pre-conceived combinations of materials, floorplans, and color palettes allowing you to make a fraction of the decisions and expedite the planning process.


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