Adding solar to an existing California ADU typically costs $4,000–$12,000 cash, depending on system size and roof complexity. HDM financing reduces effective cost ~40%.
Retrofit solar on an existing California ADU typically runs $4,000–$12,000 all-in cash, or roughly 40% less with HDM commercial-ITC financing.
Below: full details, common edge cases, and how to get instant pricing for your specific California ADU project.
For most California ADU owners, how much to add solar to an existing adu? comes up at one of three points: planning, permitting, or post-installation. Each phase has its own answer below.
If you'd rather skip the reading and see a real number for your project, our calculator delivers instant pricing without a sales call.
Easy ADU Solar is a referral platform — we negotiate with multiple licensed C-46 California installers to get you fixed pricing. We surface this question because it's one of the top-asked items by California ADU owners researching solar.
Retrofit solar on an existing California ADU typically runs $4,000–$12,000 all-in cash, or roughly 40% less with HDM commercial-ITC financing.
Under 30 seconds via our calculator — no phone or email required.
Garage conversions and JADUs are usually exempt from Title 24 solar but follow the same answer for voluntary installs.