By tradition, dzongs are constructed without the use of architectural plans. Instead construction proceeds under the direction of a high
lama who establishes each dimension by means of spiritual inspiration. Dzongs are built using
corvée labor applied as a tax against each household in the district. Under this obligation each family provides or hires a decreed number of workers to work for several months at a time (during quiet periods in the agricultural year) in the construction of the dzong. Dzongs comprise heavy
masonry curtain walls surrounding one or more courtyards. The main functional spaces are usually arranged in two separate areas: the administrative offices; and the religious functions—including temples and monks' accommodation. This accommodation is arranged along the inside of the outer walls and often as a separate stone tower located centrally within the courtyard, housing the main temple, that can be used as an inner defensible citadel. The main internal structures are again built with stone (or as in domestic architecture by rammed clay blocks), and whitewashed inside and out, with a broad red
ochre band at the top on the outside. The larger spaces such as the temple have massive internal timber columns and beams to create galleries around an open central full height area. Smaller structures are of elaborately carved and painted timber construction. The roofs are massively constructed in
hardwood and
bamboo, highly decorated at the
eaves, and are constructed traditionally without the use of nails. They are open at the eaves to provide a ventilated storage area. They were traditionally finished with timber
shingles weighted down with stones; but in almost all cases this has now been replaced with
corrugated galvanised iron roofing. The roof of Tongsa Dzong, illustrated, is one of the few shingle roofs to survive and was being restored in 2006–07. The courtyards, usually stone-flagged, are generally at a higher level than the outside and approached by massive staircases and narrow defensible entrances with large wooden doors. All doors have thresholds to discourage the entrance of spirits. Temples are usually set at a level above the courtyard with further staircases up to them. Image:PunakhaDzong.jpg|
Punakha Dzong and the
Mo Chhu Image:Simtokha Dzong 20080907.jpg|
Simtokha Dzong near
Thimphu Image:Bhutan architecture dzong courtyard.jpg|Courtyard and tower of
Rinpung Dzong at
Paro ==Modern architecture in the dzong style==