The 12-storey, 55 m high, Home Insurance Building in Chicago (USA) was designed by engineer William Le Baron Jenney. It is a steel building with a rigid frame system. Known as the “father of skyscrapers”, the Home Insurance Building is regarded as the first skyscraper. The Home Insurance Building opened a new era in tall building construction and took the title of “first skyscraper”, owing to Le Baron Jenney’s idea of using iron and steel elements for the structure of a tall building instead of thick stone walls and as a development of this, his discovery of the frame structural system consisting of a skeleton of horizontal beams and vertical columns. The frame structural system used in the Home Insurance Building became a model for subsequent tall building designs. Although it did not break the height record, the Home Insurance Building is unique in being the first building designed with a frame structural system consisting of iron and steel elements, instead of masonry walls, as structural support. Compared with a building with load-bearing masonry walls and the same number of storeys, the metal skeleton was three times lighter and the exterior walls were designed only to protect the building from adverse weather conditions and not to provide structural support. It was recognised as having many more and larger window openings in its facade than other buildings of its era. With the commencement of the use of non-structural perimeter and partition elements in tall buildings instead of thick masonry load-bearing walls, thanks to the appearance of the Home Insurance Building and the frame system, the architectural and financial value of the spaces within buildings was increased and more usable space and natural light was obtained in the interior. Thus, just as this development made the construction of tall buildings much more practical, it also increased their utility.