Understanding ADU Costs
The cost to build an ADU varies widely depending on the type, size, and placement of the unit — as well as the age and location of your property and its site-specific elements — including utilities, topography, and accessibility. Our Adapt Feasibility Study provides you an estimate of your ADU costs in a detailed financial analysis to help you make a more informed decision.
On the lower-end of the range are conversions of existing habitable space, which can be completed for under $100,000, while on the higher-end are new detached units as well as more complicated conversions, which can cost upwards of $400,000.
We know that the costs may seem overwhelming at first, but it’s also important to consider the value of adding a fully permitted additional unit to your home or property. Whether to be used as a rental, to house family members, or just provide you with some additional space, we believe ADUs are generally worth the investment once you crunch the numbers. Our experience in finance and real estate — in addition to our architectural and inspection skills — helps you better understand the viability of your project so you can make a more informed decision upfront.
Cost by Stage
Feasibility
Costs at this stage are simple. We charge a flat fee for our Adapt Feasibility Study.
Most ADU designers and builders conduct some type of feasibility study. Ours stands out in that it always includes an on-site inspection and customized financial analysis. Some companies will bundle this step into their overall fees, but we keep it separate so that there is no obligation to continue with us. Get a sample of the Feasibility Report.
Feasibility
Costs at this stage are simple. We charge a flat fee for our Adapt Feasibility Study.
Most ADU designers and builders conduct some type of feasibility study. Ours stands out in that it always includes an on-site inspection and customized financial analysis. Some companies will bundle this step into their overall fees, but we keep it separate so that there is no obligation to continue with us. Get a sample of the Feasibility Report.
Design
In the design phase, costs are scoped by our architect based on the findings in the Feasibility Study. Generally, this phase and the next phase make up about 10-20% of the overall project cost. In the design phase, our fee-structure is also fixed, based on the completion of major milestones.
City approval
Once a completed application and full set of plans has been submitted to your local jurisdiction, we bill on an hourly basis for plan check and comments until plans are approved. Our familiarity with the ADU process and the requirements of local jurisdictions help keep the number of hours in this part to a minimum.
Build
The bulk of the cost to build an ADU comes down to construction. Prices are usually quoted by contractors on a per-square-foot basis. Demand for skilled labor and materials can greatly impact these prices at any given time. Generally, construction costs usually fall in the range of $200-400/ sq.ft. This amount can be lower if converting existing habitable space. You will also be required to pay permit fees at this stage if you have not already, which are usually in the range of 5-10% of estimated construction costs.