In exceptional, but often executed projects the steel skeleton can form part of the load bearing construction of the building. In the case of a roof and dome-shaped design it can become the framework itself.

The water carrying elements are hollow cross sections, vertical and horizontal with dimensions primarily determined by loading requirements.

The cross sections can also be designed in different shapes, as long as the load requirements of a defined flow and consequently the required heating capacity are complied with.

The external skin is manufactured mainly from glass but can also be in the form of lightweight insulated sandwich panels.

One of the essential aims of steel/glass constructions is to achieve maximum transparency. In order to attain this aim, construction systems are becoming increasingly filigreed. To this end, increasing use is now made of frameworks subject to normal forces, since they require smaller-sized load transfer sections compared to structures subject to bending loads. The loads generated by normal forces act in both compression and tension. If systems are designed primarily for exposure to tensile load, further reduction of the frame structure is possible.

The result is the creation of filigree glass constructions that can be used both in facades and roofing.

Structural framework systems are essentially defined by their geometry and load. In this case, the load in the framework generates bending force and/or normal force (compression/tension). Consequently, the different types of support structure can be classified into systems subjected to normal force; systems subjected to bending force and hybrid systems that are subject to both normal and bending forces.

In facades, the loads derive from the dead load of the facade (vertical load) and from the compressing and suction effect of the wind (horizontal loads). If the glass in planar form absorbs these loads, the glass acts as a primary load-bearing element. This is the case, for example, in suspended facades, with the advantage that these facades can use thin panes that do not buckle or bulge. By hanging several panes to one another, large glass surfaces can be constructed, with the top pane carrying the entire facade. To stabilise suspended facades against horizontal loads braced structures and glass fins are often used. If the glass does not have any direct load-bearing function for the overall system, it acts as secondary support structure. There are several possibilities to reduce the secondary structure, such as complex spatial bracing.

Wind pressure and wind suction work in opposite directions, so that bracing is required on both sides. This bracing can be arranged spatially, on the outside, on both sides or also inside a double-skin glass envelope. A small number of basic structures provide a large variety of possible variants.

The stiffening ropes of these systems are generally pre-tensioned, so that one rope remains tensioned while the other is exposed to maximum load.

These pre-tensioning forces must be absorbed by the building or by supports in the system. If the building forms the primary structure, it must be sufficiently stiff to develop the requisite reaction forces. If this requirement cannot be met, inserting a pressure element can close the system. In this case, the primary structure will only have to absorb the dead loads and wind forces, because the tensile forces inside the system are short-circuited.