A chapter house or chapterhouse is a building or room that is part of a cathedral, monastery or collegiate church in which larger meetings are held. When attached to a cathedral, the cathedral chapter meets there. In monasteries, the whole community often met there on a daily basis for readings and to hear the abbot or senior monks talk. When attached to a collegiate church, the dean, prebendaries and canons of the college meet there. The rooms may also be used for other meetings of various sorts; in medieval times monarchs on tour in their territory would often take them over for their meetings and audiences. Synods, ecclesiastical courts and similar meetings often took place in chapter houses.
When part of a monastery, the chapter house is generally located on the eastern wing of the cloister, which is next to the church. Since many cathedrals in England were originally monastic foundations, this is a common arrangement there also. Elsewhere it may be a separate building. The chapter house comprises a large space, in order to hold all the monks of the monastery, and is often highly ornamented. Typically there is seating around, often built into, all the walls of the room, often in stone, with the central space left open. The seats for the senior members are often larger than the others, and may be raised on a dais. Usually there is only one doorway, and though the room is well-lit where the location allows, the windows are often too high to allow a view in from outside (or eavesdropping). Many larger chapter houses are designed with vestibules for attendants and those waiting to be called, where opening onto a cloister does not provide such a space. There is often a fireplace, and altars are found in some examples, sometimes added later.
Many medieval rooms use stone vaulting supported by columns in the centre of the space, as used for other more utilitarian large rooms in monasteries with a generous budget. Others have much higher roofs. The shape of the room is usually designed to allow good audibility for speakers from all parts of the room. It may be rectangular, tending towards the square, but octagonal and other near-circular plans are an English speciality, with that at Worcester Cathedral probably the earliest. Most, like those at Wells Cathedral, Lichfield Cathedral, Westminster Abbey and Lacock Abbey have a single central column, from which the high roof vaulting spreads. York Minster has a wooden roof and no central column. Many have elaborate benched arcades round the wall, with crocketed frames for the seats. English chapter houses tend to be more elaborate and highly decorated than Continental ones, and the octagonal shape allowed for spectacular displays of stained glass, now mostly lost, though not at York. Except at Westminster Abbey any paintings have been lost, but English designs, with their emphasis on carved arcades and windows, did not leave the large wall spaces found in most Continental chapter houses.