The Forbidden City in Beijing is the imperial palace of the Ming dynasty; this vast complex of hundreds of buildings is built through the repetition and modulation of a single timber structural language. The basic element of Chinese timber architecture takes here its most developed, most ceremonial form: the dougong.

The dougong is a set of interlocking timber brackets placed between the column capital and the roof beams. It gathers the load of the heavy, broad-eaved roof, spreads it sideways, and transfers it to the timber columns below. The key point is that this entire system — columns, beams, dougong blocks — is joined without nails, by precise timber joinery alone. This makes the building both demountable for repair and able to dissipate energy by moving in an earthquake. The walls are not load-bearing; the load is entirely in the timber frame, so the walls can freely be partition or window.

The dougong is also a modular measuring system: standard block units set the size and hierarchy of the building; a more important structure carries a dougong of more layers. The whole city is laid out on a north-south ceremonial axis, with symmetrical courtyards and graded gates. The Forbidden City is thus not a single building but a scalable architectural system built from one structural grammar (timber frame + dougong).