What does it cost to build an ADU (accessory dwelling unit) in Marin?

May 7, 2022

Right now, with inflation-- especially in construction--and historically high material prices fluctuating, can we really know a good estimate of the price of an accessory dwelling unit in Marin?


Nothing is assured, but having a budget is possible, especially if you are willing to be flexible in materials and know how to navigate cost saving ADU rules in California.

Here's how we think about this:

·     Estimated $10-12 SF in permit fees paid. No impact fees apply for ADUs under 750 SF.   And, if you plan to rent your unit within affordability guidelines (not hard to do) fees can go way down.  

·     Basic site work: $25,000. For a level lot with sufficient access for construction equipment, typical site work to prepare a buildable pad for the ADU.

·     Estimated architectural construction costs:  5% if negotiated. This includes construction documents and application package.  ADUs can often be of very simple design or even off-the shelf.

·     Standard finish materials are included in our estimated build prices, such as Quartz counter tops, pre-built wood cabinets, and porcelain tile floor.

·     Solar: $10,000-$15,000 may be optional if the ADU is attached.

Build costs in general have gone up over the past year, due to both material and labor shortages. We have taken those costs into account for ADU costs in Marin.

Bottom line: $350-425 SF to build an ADU.

Our target estimate to build a one-bedroom ADU in Marin, on a flat lot--$275,000.

With rents increasing and demand surging, this could be one of the best investments available to homeowners.


The VADU Benefit:
We work only for the property owner--helping enhance the value of their properties and realize financial/personal goals.

We manage the conversion of underperforming commercial spaces to extremely valuable residential housing.

We know the law, municipalities, architects and builders to quickly and cost-effectively create thriving multi-family properties to rent or sell or an ADU on/in your home.

We will give you a free assessment on the potential value of your property.

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