Mechanical, Electrical, and Plumbing (MEP) refers to the installation of services which provide a functional and comfortable space for the building occupants.
MEP's design is important for planning, decision-making, accurate documentation, performance- and cost-estimation, construction, and operating/maintaining the resulting facilities.
[1] MEP specifically encompasses the in-depth design and selection of these systems, as opposed to a tradesperson simply installing equipment.
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.
Virtually all modern buildings integrate some form of AC mains electricity for powering domestic and everyday appliances.
Such systems typically run between 100 and 500 volts, however their classifications and specifications vary greatly by geographical area (see Mains electricity by country).
[9] Advances in technology and the advent of computer networking have led to the emergence of a new facet of electrical systems incorporating data and telecommunications wiring.
As a result, it is more common for this wiring to be installed or serviced by competent amateurs, despite constant attempts from the electrical industry to discourage this.
In commercial environments, these distribution systems expand to accommodate many more users, as well as the addition of other plumbing services such as hydroponics, irrigation, fuels, oxygen, vacuum/compressed air, solids transfer, and more.