Frame structure

A frame structure carries a building’s weight on a connected framework of columns and beams rather than on its walls. Slabs pass loads to beams, beams to columns, and columns down to the foundations. The frame can be reinforced concrete, steel or timber. Because the walls carry no structural load, they become infill that simply divides space and forms the outer skin. In Turkish it is called iskelet sistem.

How it differs from masonry

In load-bearing masonry, walls both enclose and support, which limits window sizes, openings and later alterations. In a frame structure, wall positions are far freer. The free plan and free facade that Le Corbusier set out among his principles for modern architecture come directly from this separation of structure and enclosure. Wide windows, open-plan homes and flexible office floors all become easier with a frame.

Design considerations

• Columns placed on a regular grid give the most efficient result, structurally and architecturally.
• In seismic regions the frame is designed to work together with shear walls.
• Junctions between infill walls and the frame need proper detailing to avoid cracking.

The frame also guides visualisation. A 3D model that gets the rhythm of columns and beams right keeps every scene, from facade to interior, consistent with the real building.