Measuring-up in timber: A critical perspective on mid- and high-rise timber building design

Abstract

Architects, engineers, and researchers alike often cite practical reasons for building with wood. Since the development of curved glulam beams and columns over a century ago, the widespread use of massive structural timber elements has allowed architects and engineers to design and build in wood with unprecedented speed and scale. Moreover, rising concerns of climate change and the carbon dioxide emissions associated with construction encourage the use of wood as a viable alternative to steel and concrete, due to CO2 sequestration in trees. In mid- and high-rise buildings, the current shift from steel and concrete towards massive structural timber elements like glulam, laminated-veneer lumber (LVL), and cross-laminated timber (CLT) is evident in a number of recently completed timber buildings in Europe, ranging from seven to nine storeys. Several speculative design proposals have also been made for ‘timber towers’ of 30, 42 and even 65 storeys, recognising that designing with massive structural timber elements in high-rise buildings is still in its infancy. This paper offers a new perspective on building with wood at this scale, beyond carbon sequestration and construction. Criticism of existing projects and proposals, including the authors’ own previous design work, is used to highlight the shortcomings of thinking about wood purely as a substitute material for steel and concrete in tall buildings. Two positive case studies are used to further show how wood offers new opportunities for architects and engineers to engage with the materiality, tectonics, and structure of mid- and high-rise without neglecting wider urban, cultural, and social issues. This discussion seeks to begin a debate on the future role and wider use of structural timber in contemporary architecture.