Evolution and rationalization of timber frame design in Istanbul in the second half of the nineteenth century

ABSTRACT Until the mid-19th century, the traditional Istanbul house was a building constructed with a timber frame with adobe or brick infill (hımış). This timber frame construction technique evolved in the second half of the 19th century into a timber frame with closely placed thin vertical braces without infill. The causes behind this change are still unknown. This study traces the causes of change and the evolution pattern of Istanbul timber-frame construction through Ottoman building-cost estimates, cost journals and other written sources of the period. The Western influence on science and technology affected the newly emerging engineering discipline in Istanbul and caused the gradual change in timber-frame design. However, the rationalization of timber-frame design went hand in hand with the industrialization of the woodworking sector in the Western world, whereas in Istanbul the lack of steam-powered woodworking machines caused the extensive use of hand-sawn timber-frame elements. This violated the basic design principles of vertically braced timber frames and caused the construction of fragile frames in need of frequent maintenance. Only in the last decade of the 19th century did the industrialization of the woodworking sector lead to the full rationalization of timber-frame construction. Identifying the timber frame types of this transition period is of crucial importance while dating the historic timber structures and assessing their structural strengths and weaknesses.