Architectural engineering, also known as building engineering or architecture engineering, is an engineering discipline that deals with the technological aspects and multi-disciplinary approach to planning, design, construction and operation of buildings, such as analysis and integrated design of environmental systems (energy conservation, HVAC, plumbing, lighting, fire protection, acoustics, vertical and horizontal transportation), structural systems, behavior and properties of building components and materials, and construction management.From reduction of greenhouse gas emissions to the construction of resilient buildings, architectural engineers are at the forefront of addressing several major challenges of the 21st century. They apply the latest scientific knowledge and technologies to the design of buildings. Architectural engineering as a relatively new licensed profession emerged in the 20th century as a result of the rapid technological developments. Architectural engineers are at the forefront of two major historical opportunities that today's world is immersed in: (1) that of rapidly advancing computer-technology, and (2) the parallel revolution arising from the need to create a sustainable planet.Distinguished from architecture as an art of design, architectural engineering, is the art and science of engineering and construction as practiced in respect of buildings.