Fireproofing in the context of "Polyester"

Building insulation is material used in a building (specifically the building envelope) to reduce the flow of thermal energy. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation (e.g. for vibrations caused by industrial applications). Often an insulation material will be chosen for its ability to perform several of these functions at once.

Since prehistoric times, humans have created thermal insulation with materials such as animal fur and plants. With the agricultural development, earth, stone, and cave shelters arose. In the 19th century, people started to produce insulated panels and other artificial materials. Now, insulation is divided into two main categories: bulk insulation and reflective insulation. Buildings typically use a combination.

The earliest stage of skyscraper design encompasses buildings built between 1884 and 1945, predominantly in the American cities of New York and Chicago. Cities in the United States were traditionally made up of low-rise buildings, but significant economic growth after the American Civil War and increasingly intensive use of urban land encouraged the development of taller buildings beginning in the 1870s. Technological improvements enabled the construction of fireproofed iron-framed structures with deep foundations, equipped with new inventions such as the elevator and electric lighting. These made it both technically and commercially viable to build a new class of taller buildings, the first of which, Chicago's 138-foot (42 m) tall Home Insurance Building, opened in 1885. Their numbers grew rapidly, and by 1888 they were being labelled "skyscrapers".

Chicago initially led the way in skyscraper design, with many constructed in the center of its financial district during the late 1880s and early 1890s. Sometimes termed the products of the Chicago school of architecture, these skyscrapers attempted to balance aesthetic concerns with practical commercial design, producing large, square palazzo-styled buildings hosting shops and restaurants on the ground level and containing rentable offices on the upper floors. In contrast, New York's skyscrapers were frequently narrower towers which, more eclectic in style, were often criticized for their lack of elegance. In 1892, Chicago banned the construction of new skyscrapers taller than 150 feet (46 m), leaving the development of taller buildings to New York.