The siheyuan is the classic northern Chinese courtyard dwelling: rooms on four sides face inward around a private court, presenting blank walls to the lane and ranking family members by orientation, with the senior hall to the north on the favoured axis. These houses line up along hutong, the narrow service lanes laid out on the grid of Yuan Dadu in 1267 and inherited by Ming and Qing Beijing. Repeated block by block, the courtyard-and-lane pattern produced a low, dense, walled-cell fabric quite distinct from the open street city. It encoded Confucian family hierarchy and fengshui orientation in domestic form.
The siheyuan-and-hutong grain gave the Chinese city its characteristic low-rise, inward-facing, walled-compound texture, a pattern echoed centuries later in the socialist danwei superblock.