Portal frame construction is a method of building and designing simple structures, primarily using steel or steel-reinforced precast concrete. The connections between the columns and the rafters are designed to be moment resistant, i.e. they can carry bending forces. This allows the frames to be stable while only having simple foundations, only able to withstand compressive, tensile and shear forces. Foundations capable of carrying moments can be deep and are generally very expensive to build compared to connections. Portal frame construction is typically seen in warehouses, barns and other places where large, open spaces are required at low cost. Several companies manufacture software to assist in the efficient design of portal frame structures to design codes such as BS 5950.

Structural engineering