This study presents an analysis of the impacts of climate change on thermal comfort and energy performance of residential buildings in Ghana, in sub-Saharan Africa, and explores mitigation as well as adaptation strategies to improve buildings’ performance under climate change conditions. The performances of the buildings are analyzed for both recent and projected future climates for the Greater Accra and Ashanti regions of Ghana, using the IDA-ICE dynamic simulation software, with climate data from the Meteonorm global climate database. The results suggest that climate change will significantly influence energy performance and indoor comfort conditions of buildings in Ghana. However, effective building design strategies could significantly improve buildings’ energy and indoor climate performances under both current and future climate conditions. The simulations show that the cooling energy demand of the analyzed building in the Greater Accra region is 113.9 kWh/m² for the recent climate, and this increases by 31% and 50% for the projected climates for 2030 and 2050, respectively. For the analyzed building in the Ashanti region, the cooling energy demand is 104.4 kWh/m² for the recent climate, and this increases by 6% and 15% for the 2030 and 2050 climates, respectively. Furthermore, indoor climate and comfort deteriorate under the climate change conditions, in contrast to the recent conditions.

Low-carbon buildings and construction products can play a key role in creating a low-carbon society. Cross-laminated timber (CLT) is proposed as a prime example of innovative building products, revolutionising the use of timber in multi-storey construction. Therefore, an understanding of the synergy between structural engineering design solutions and climate impact of CLT is essential. In this study, the carbon footprint of a CLT multi-storey building is analysed in a life cycle perspective and strategies to optimise this are explored through a synergy approach, which integrates knowledge from optimised CLT utilisation, connections in CLT assemblies, risk management in building service-life and life cycle analysis. The study is based on emerging results in a multi-disciplinary research project to improve the competitiveness of CLT-based building systems through optimised structural engineering design and reduced climate impact. The impacts associated with material production, construction, service-life and end-of-life stages are analysed using a process-based life cycle analysis approach. The consequences of CLT panels and connection configurations are explored in the production and construction stages, the implications of plausible replacement scenarios are analysed during the service-life stage, and in the end-of-life stage the impacts of connection configuration for post-use material recovery and carbon footprint are analysed. The analyses show that a reduction of up to 43% in the life cycle carbon footprint can be achieved when employing the synergy approach. This study demonstrates the significance of the synergy between structural engineering design solutions and carbon footprint in CLT buildings.

In this study, the life cycle environmental implications of modular multi-storey building with cross-laminated timber (CLT) volumetric elements are analysed, considering the product, construction, service life, end-of-life and post-use stages. A bottom-up attributional approach is used to analyse the environmental flows linked to the global warming potential (GWP), acidification potential (AP) and eutrophication potential (EP) impacts of the building for a 50-year reference study period. The result shows that the building’s life cycle impacts can vary considerably, depending on the energy production profile for the operation of the building. The product, construction and end-of-life stages constitute a significant share of the life cycle impacts, and the importance of these stages increase as the energy production profile evolves towards a low-carbon energy mix. For the GWP, the product and construction stages constitute 13% of the total life cycle impact when the operational energy is based on a coal-based marginal electricity. The contribution of this stage increases to 81% when electricity is based on a plausible long-term Swedish average mix. The patterns of the life cycle EP and AP impacts are also closely linked to the energy production profile for the assessment. The analysis shows that a 5% reduction in the GWP impact in the product stage is achievable with emerging solutions for the improved structural design of CLT buildings. This study highlights the need for strategies to improve the life cycle environmental profile of modular CLT buildings.