The great 19th century architect of skyscrapers, Louis Sullivan, promoted an overriding precept to architectural design: "Form follows function". While the notion that structural and aesthetic considerations should be entirely subject to functionality was met with both popularity and scepticism, it had the effect of introducing the concept of "function" in place of Vitruvius "utility". "Function" came to be seen as encompassing all criteria of the use, perception and enjoyment of a building, not only practical but also aesthetic, psychological and cultural.
Nunzia Rondanini stated, "Through its aesthetic dimension architecture goes beyond the functional aspects that it has in common with other human sciences. Through its own particular way of expressing values, architecture can stimulate and influence social life without presuming that, in and of itself, it will promote social development. To restrict the meaning of (architectural) formalism to art for art's sake is not only reactionary; it can also be a purposeless quest for perfection or originality which degrades form into a mere instrumentality".[10]
Ivar Holm points out that the values and attitudes which underly modern architecture differ both between the schools of thought which influence architecture and between individual practising architects.[11] Among the philosophies that have influenced modern architects and their approach to building design are rationalism, empiricism, structuralism, poststructuralism, and phenomenology.
In the late 20th century a new concept was added to those included in the compass of both structure and function, the consideration of sustainability. To satisfy the modern ethos a building should be constructed in a manner which is environmentally friendly in terms of the production of its materials, its impact upon the natural and built environment of its surrounding area and the demands that it makes upon non-sustainable power sources for heating, cooling, water and waste management and lighting.
There is also a concept among architects that although architecture does not exist in a vacuum, architectural form cannot be merely a compilation of historical precedent, functional necessities, and socially aware concerns, but that to achieve significance, a work of architecture must be a transcendent synthesis of all of the former and a creation of worth in and of itself. (from http://en.wikipedia.org/wiki/Architecture)
