Consult with a licensed, professional remodeler who is experienced at building ADUs. They will look at everything from required setbacks to the value of comparable homes in your area. They should be able to tell you not only whether an ADU can be built on your lot – and the answer is almost always yes, it may just require some outside of the box thinking – but whether it’s an investment that makes sense for your home in your particular neighborhood. This is a decision you will need to make.