Darbazi

The darbazi is a traditional house type of Georgia whose defining feature is its roof: a stepped, pyramid-like vault of logs called the gvirgvini, built up in layers that turn and narrow toward a central opening. The opening at the top serves both as a window and as the smoke outlet for the hearth below.

The name is Georgian, derived from the Persian darvāze ("gate"). Similar lantern roofs are known across Asia Minor and the South Caucasus: in Armenia they are called glkhatun or hazarashen, in Turkey kırlangıç kubbe or kırlangıç örtü ("swallow dome"), and in Azerbaijan karadam.

How the roof is built

Hewn logs and beams are laid in stepped courses, each projecting inward over the one below, so that the opening narrows as the roof rises until only the central hole remains. This is corbelling: no course spans the whole room, which is why the method can be built from comparatively short timbers. The vault rests on pillars, and a solid central timber upright called the deda-bodzi ("mother pillar") carries much of the weight of the corbelled roof. Houses were often set partly below ground, with finely carved beams and pillars.

History

The Roman writer Vitruvius, in the 1st century BC, described a dwelling of Colchis (western Georgia) built of stacked logs, and this is often cited as an ancient precursor of the darbazi. The type continued to be built into the 20th century, with regional variants. It is most associated with Kartli, Kakheti and Samtskhe-Javakheti. Scholars have suggested the form may have influenced early Georgian church design.

Related roofs

The darbazi is a timber relative of masonry corbelled domes found elsewhere (see khmer-corbel-vault and the stone corbelled roofs of the Hauran). It differs from the masonry domes of Iran and Turkey in using timber rather than brick or stone.