A discipline that deals with the technological aspects of buildings, including the properties and behavior of building materials and components, foundation design, structural analysis and design, environmental system analysis and design, construction management, and building operation.

Environmental systems, which may account for 45-70% of a building's cost, include heating, ventilating and air conditioning, illumination, building power systems, plumbing and piping, storm drainage, building communications, acoustics, vertical and horizontal transportation, fire protection, alternate energy sources, heat recovery, and energy conservation. In addition, to help protect the public from unnecessary risk, architectural engineers must be familiar with the various building codes, plumbing, electrical, and mechanical codes, and the Life Safety Code. The latter code is similar to a building code and is designed to require planning and construction techniques in buildings which will minimize possible hazards to the occupant.
Difference from architecture
A common confusion is the distinction between architecture and architectural engineering. In essence, architectural engineering is a component of architecture. Architects are directly responsible for the form and appearance of a building, including the way in which people use and experience the spaces of the building, and they typically act as the leader of the design team. They also coordinate the various engineering requirements of a building project. Architectural Engineering concentrates on ensuring that "the building works" (that it stands up, that the HVAC system operates, that light and power are delivered as needed).