Radical decarbonisation in the construction sector is an urgent need to mitigate climate change. Therefore, new environmentally
sound technologies in timber have to be developed and applied for seismic strengthening of buildings in seismic active regions in
order to allow them for a second life cycle. In combination with energy retrofit, such seismic intervention backs the EU renovation
wave and empowers a clean energy system, because buildings operational heat energy demand will be lowered close to nearly Zero
Energy Building (nZEB) level with an improved building envelope. The intervention adapts concepts and principles originally
developed for precast concrete construction, post-tensioned (PT) timber frame systems have been developed and tested since 2005
at the University of Canterbury. The technology takes advantage of unbonded post-tensioned steel tendons passing through internal
cavities in timber beams or walls to create a moment resisting connection. The seismic demand is satisfied through controlled rocking
between structural elements and tendon elongation, which ensures recentering capabilities. Post-tensioned timber frames as twodimensional or three-dimensional structure are an emerging concept in timber engineering with great potential for the creation of
high-performance and cost-efficient joints. The suitability as a retrofit concept is evaluated on two case studies that are part of the
ProGETonE H2020 research program, which aims to provide an innovative, and integrated retrofit concept. Both measures serve to
prolong the use of the building and avoid its demolition, a reuse case almost at is best, providing ultimate circularity index results.
Therefore, only almost, because such a deep renovation intervention consumes new resources to build and also requires the
replacement of specific components as windows or even the adaptation of floor plans to today’s needs. Decarbonisation effects are
revealed by calculation of Life Cycle Assessment (LCA) indicators for timber-based external retrofit envelope components that are
assembled onto existing buildings for stiffer structures and for insulation purposes. The design and technology concept revealed
allowing for the combination of strong structural behavior, necessary building physics performance to achieve for nZEB energy
demand; with new Cross-Laminated Timber (CLT) components exposed also connection details and construction processes are
discussed.
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Radical decarbonisation in the construction sector is an urgent need to mitigate climate change. Therefore, new environmentally
sound technologies in timber have to be developed and applied for seismic strengthening of buildings in seismic active regions in
order to allow them for a second life cycle. In combination with energy retrofit, such seismic intervention backs the EU renovation
wave and empowers a clean energy system, because buildings operational heat energy demand will be lowere...
»