Costs

The cost of connections is a significant proportion of the overall cost of the structure.

The cost of steel connections is very significant. In broad terms, the cost of a steel frame can be divided into three approximately equal parts: one third for the material, one third for transport and erection, and one third for fabrication, which is principally the cutting, drilling, bolting and welding to make the connections.

Because of the additional cost of rigid connections they are rarely used in multi-storey buildings, although they are frequently used in portal frame construction for single storey buildings.

This can affect the overall design method adopted. For example continuous design is rarely used for multi-storey steel framed buildings because the additional cost of the connections needed generally outweighs the savings in the size of the steel members.

Connections afford some tolerance, allowing minor site adjustments.

Connections can also provide some tolerance. For example, a splice between columns can include provision for packing plates during erection to enable fine adjustment of column height to match an existing building. Such packing plates are also commonly used in column base details to adjust for inaccuracies in the level of the concrete foundation pad.