Which authority is responsible for defining local regulations regarding building codes?

Local regulations regarding building codes are defined by municipalities. This is because municipalities have the authority to establish building bylaws that reflect the specific needs, characteristics, and preferences of their communities. These bylaws encompass various aspects of building, including zoning, safety standards, and design requirements, ensuring that they are tailored to the local context.

Provincial governments set overarching regulations and standards for building codes, which municipalities must adhere to, but they allow municipalities to adapt these standards to local circumstances. Federal agencies are mainly involved in broader regulatory frameworks and do not govern local building code regulations directly. Private developers may influence building practices or designs but do not have the authority to establish or define the regulations themselves. Therefore, municipalities play a critical role in local governance of building codes, making them the correct answer.