What is the "building envelope guidelines"?

Question

What is the "building envelope guidelines"?

Answer 1

Building envelope guidelines are set out in local building codes (ie, they are law) that define the maximum volume a building can fill.  The building envelope is the entire exterior skin of a building.  Through devices like set-backs (how far back from a property line a building must be), air rights (who owns or regulates the volume of air above a property), etc, cities and towns will enact building envelope guidelines to control the size and shape of buildings, the character of the building in relation to the street, even to set how much light will reach the street.  For example, NYC has complicated building envelope guidelines in the twenties largely helped to determined the form of the Empire State and the Chrysler buildings.  The architectural illustrator Hugh Ferris did a a famous series of drawings in the twenties to illustrate these guidelines.

Most recently, Jean Nouvel has designed a building adjacent to the MoMA in New York City which has a form that pushes the building envelope guidelines to the limit (or so he claims).