Under Building Control Law, any person who intends to modify building must obtain a permit from the local authorities. Thailand’s earlier regulatory approach to rooftop solar photovoltaic (PV) systems treated such installations as non-modifications of a building only when strict conditions were met under Building Control Law.
Under the previous regulation, rooftop solar panels were exempted from the definition of building modification if (i) the installation area did not exceed 160 square meters, (ii) the total load did not exceed 20 kilograms per square meter, and (iii) the owner obtained a structural stability inspection and certification from a licensed civil engineer.
The new regulation significantly simplifies this regime by narrowing the requirement to a single technical criterion: the total weight of the solar PV system must not exceed 20 kilograms per square meter in the area of installation. All other conditions—such as the restriction on installation area, the need for engineer certification, and the obligation to notify the local authority—have been removed.
This shift represents a clear regulatory liberalization, effectively developing the compliance burden for homeowners and installers while removing the procedural checkpoints previously embedded in the approval process.
This legislative revision reflects a broader national policy direction aimed at facilitating renewable energy adoption and encouraging decentralized power generation. The removal of administrative and technical prerequisites lowers the entry barriers for rooftop solar installations, potentially increasing adoption rates among residential and small commercial users.