ADU Garage Conversion

[James Stoddard]

I'm doing a simple 20X20 ADU garage conversion (400 sq. ft). I hired an architect and he did some rough designs. Now he says he needs to hire an engineer. Does that make sense? I'd heard that simple garage conversions didn't require an engineer. How much should I expect to spend? The plan involves a common wall connected to the house.

Any advice would be much appreciated!

[Ty Coutts]

I would recommend an engineer for this project for these reasons:

1. This structural connection between the ADU and the main house typically requires engineering calculations to ensure proper load distribution and structural integrity.

2. Even for a "simple" garage conversion, there may be structural changes needed to make the space habitable.

3. An engineer can help ensure that the conversion meets all current building codes and safety standards for residential living spaces.

4. Having engineering plans and calculations can streamline the permitting process, as many local authorities require this documentation for ADU conversions.

I can't give an invoice estimate as I am not well versed in how engineers price their work, but I would assume something around $5,000 for engineering services on a project of this size.