Which structural concept allowed for the construction of taller and lighter structures?

The concept that enabled the construction of taller and lighter structures is the use of space frames. Space frames are three-dimensional structures comprised of interconnected elements that create a rigid framework, capable of distributing loads evenly across their members. This design allows for the creation of expansive and open interiors without the need for numerous supporting walls, which are typically necessary in conventional construction methods.

Space frames utilize compression and tension forces effectively, allowing architects and engineers to design structures that rise higher and possess significantly reduced weight compared to traditional solid materials. The lightweight characteristics of space frames lead to less material usage, which further contributes to efficiency in construction and minimizes the overall environmental footprint.

While post and lintel systems and keystone arches have historically contributed to the ability to build structures, they are limited in height and span. Flying buttresses, while allowing for taller walls and the support of vaulted ceilings, are generally associated with specific architectural styles (notably Gothic) and do not provide the same level of flexibility and efficiency as space frames in modern construction. Thus, space frames represent an essential advancement in architectural technology, facilitating the creation of light yet robust structures.