Mechanical, electrical and plumbing (MEP) refers to these aspects of building design and construction. In commercial buildings, these elements are often designed by a specialized engineering firm. MEP design is important for planning, decision making, accurate documentation, performance- and cost-estimation, construction, and operating/maintaining the resulting facilities.
MEP specifically encompasses the in-depth design and selection of these systems, as opposed to a tradesperson simply installing equipment. For example, a plumber may select and install a commercial hot water system based on common practice and regulatory codes. A team of MEP engineers will research the best design according to the principles of engineering, and supply installers with the specifications they develop. As a result, engineers working in the MEP field must understand a broad range of disciplines, including dynamics, mechanics, fluids, thermodynamics, heat transfer, chemistry, electricity, and computers.