LIC #: 1002689

ADU Construction Cost in the Bay Area

Looking for a detailed breakdown of the ADU construction Cost in the Bay Area? You will want to read this piece to understand how much you can expect to budget for the main construction aspects and features that go into the project.

ADU Construction Cost in the Bay Area

Factors that Influence the Cost of ADU 

To start, it is important to know the type of ADU your property is eligible for and understand the construction process that goes into it.

The cost of building an ADU in the Bay Area depends on the design—especially whether it will be detached from or attached to the main house and what materials and finishes will be required.

  • Where you live, because the cost of building an ADU will greatly depend on the housing market in your location.
  • Size of the ADU, every square foot you add to your ADU plan increases the construction costs.
  • Type of ADU, a detached ADU would cost more than an attached ADU.
  • Site and foundation preparation, the costs of creating and creating space on your property, preparing the concrete works, and laying the foundation can range.
  • Finishes and design elements, such as eye-catching focal points and custom finishing, come at additional costs to the standard price.
  • Bay Area building permits fees and zoning fees.

We like to break it down into three main phases:

  • ADU Ordinances, Planning, and Permitting
  • The ADU Construction
  • Finishes

For more details on how Done Right Home Remodeling can help design and build your ADU, please explore our Bay Area ADU construction services.

 

Bay Area’s Cost of ADU Ordinance, Planning, and Permitting 

Before we help you explore your options for adding an ADU, we ensure your property is eligible. This involves checking the maximum square footage allowed and the property setbacks that influence your ADU location.

Typically, ADU design cost in the Bay Area can range from 8-15% of your total project cost. With the detailed and engineered set of drawings, the permitting process begins, and you will need both zoning and building permits, which can range from $25 to $4,000 and $450 to $15,000, respectively.

Depending on your type of ADU (detached or attached), the required documents include the following:

  • Architectural layout and site-plan
  • Structural engineering plans (for foundation, framing, wall, roof, and ceiling framing)
  • Title 24 Report (energy calculations per Bay Area regulations)
  • Electrical Plan
  • Survey of Lot
  • Soils Report

 

Detailed ADU Construction Cost in the Bay Area

This phase involves site preparation and construction costs, which take the largest portion of your project budget. This cost can vary depending on your location, the size of the ADU, the overall design, plans, and the quality of the building materials.

Depending on your selections for appliances, flooring, countertops, lighting, fixtures, bathroom vanity, and more, the finishing cost of your ADU can range from 30% to 50% of your initial investment.

 

Type of Service Average Price
Materials, including lumber, sheathing, joists, roofing, windows, door, trim, and more about 45% to 50% of the total cost of your project
Foundation $4 and $25 per square foot
Framing $25,000 on average
Finishing $10 and $60 per square foot
Systems, including electrical, plumbing, and HVAC $3,400 to $10,400 on average
Labor 40% of your ADU project’s cost
Design and Permits 10-15% of your ADU project’s cost
ADU Costs by Type

Bay Area ADU Costs by Type

Here are our five types of ADUs that you can choose from, all of which impact the total cost of your project. Check out the following to see how much you might spend to build an ADU on your property, not including permits and other fees.

 

ADU Type                  Average Min Price Average Max Price
Attached ADU $100,000 $216,000
Detached ADU $110,000 $285,000
Junior ADU $60,000 $150,000
Second-Story ADU $128,000 $225,000
ADU Garage conversion $60,000 $150,000

 

At Done Right Home Remodeling, we care about you knowing and understanding your overall Bay Area ADU construction cost so you can budget accordingly. We will also handle all your ADU plans and permits, and prepare your site and foundation as we construct your unit.