BPA (Bouthillette Parizeau) is a Canadian engineering firm specializing in building engineering services, including mechanical, electrical, structural, civil, sustainable development, energy efficiency, and building science for institutional, commercial, multi-residential, and industrial markets. With offices across Canada, it supports architects, property managers, and contractors in designing sustainable, low-carbon buildings. The firm has grown through multiple acquisitions, positioning it as one of Canada's largest consulting engineering firms.