Is Solar required on all Residential constructions? Do ADUs also require Solar? Any exceptions?
Updated: Feb 10, 2022
Per the new 2019 energy code, all new residential constructions are required to have a solar power system. By New Constructions, the energy code means completely new constructions and not Additions/Alterations/Conversions.
If the permit for the new residential construction is applied post 1st Jan 2020, the city would want it to comply with the new 2019 energy code. The only time we can claim exemption from the solar power requirement is if any of the below requirements are met.
There is insufficient solar exposure on the roof (< 80 SF) due to exterior sharing such as trees, hills, adjacent man made structures
If the building is a fire rebuild. This exemption is available only in some cities
The new energy code does NOT allow ANY upgrades to the envelope, mechanical or plumbing systems of the project to offset the solar power requirement, unlike the earlier versions of the energy code.
In the case of ADUs too, all newly built detached ADUs are considered as new constructions and require the solar power system. However, any attached ADU or any ADU conversion (attached or detached) is considered an Addition and hence does not trigger the solar power system requirement.
Further Reading: Is my ADU an Addition or a New Construction? Hence, would it require to have solar?