36 BCD SPECIAL REPORT ON HISTORIC CHURCHES 25 TH ANNUAL EDITION URNES and Norway’s Stave Church Preservation Programme Felicity Fox D URING THE Middle Ages, stave churches could be found across Europe and somewhere between 1,000 and 2,000 were built. Today, only 28 remain in Norway, with just three examples in Sweden, Poland and England (at Greensted, Essex). Stave construction uses solid walls of upright timber posts as a load-bearing component, without wattle and daub or other forms of infill panels. Construction therefore relies on plentiful supplies of timber. The wooden walls, which are raised off the ground by a masonry plinth, consist of posts or ‘staves’ rising from a horizontal sill beam at the base to the wall plates at the top, with vertical timbers between. In the Norwegian examples a complex jointing system was developed to ensure that the corner posts were securely fixed to the beams above and below, and the roofs were supported by elaborate trusses, usually with no ceiling beneath. These churches demonstrate some of the most advanced construction techniques of the Middle Ages. Stave churches vary in size and style. The simplest examples consist of a nave and chancel alone, and the solid timber walls provide the sole structural support for the roof. However, a mast was sometimes introduced in the centre of the nave to provide additional support for the ridge beam. In the most complex examples such as Urnes in the west of Norway, the nave was elevated on colonnades of staves with aisles on either side. Like all medieval buildings, stave churches have also undergone a range of visual and structural transformations, moulding to accommodate centuries of Stave construction of the so-called simple type, for example Haltdalen stave church: 1) nave, 2) chancel, 3) corner post, 4) wall planks, 5) floor, 6) sill beam, 7) lower wall plate, 8) higher wall plate, 9) quadrant bracket, 10) rafter, 11) scissor brace, 12) collar beam, 13) purlin, 14) ridge piece (Illustrations: Norwegian Directorate of Cultural Heritage, based on drawings by Håkon Christie) Stave church with interior posts, as at Borgund: 1) nave, 2) aisle, 3) chancel, 4) apse, 5) raft beam, 6) nave post, 7) wall planks, 8) pentice, 9) floor, 10) post, 11) raft beam, 12) aisle sill beam, 13) lower aisle wall plate, 14) upper aisle wall plate, 15) quadrant bracket, 16) cross brace, 17) string beam, 18) nave bressummer, 19) lower nave wall plate, 20) upper nave wall plate, 21) quadrant bracket, 22) rafter, 23) nave scissor beam, 24) nave purlin, 25) nave collar beam, 26) nave ridge beam.