Retrofitting existing office buildings towards life-cycle net-zero energy and carbon

Abstract

• Cost optimisation of retrofitting towards life-cycle net-zero energy and carbon. • Applying an integrated design process and selecting optimal retrofitting solutions. • Optimal solutions for life-cycle net-zero and maximising life-cycle payback cost. Maximum cost reduction is 116.3% and 103.5% for life-cycle net-zero energy and carbon buildings. • Proposed framework can reduce greenhouse gas emissions and mitigate climate effects. Energy devices for achieving net-zero operating energy and carbon generally entails additional embodied energy and carbon during the production and disposal stages. For a building to be considered as truly life-cycle net-zero, the energy use or greenhouse gas emissions occurring across each stage of its life span must be offset. Retrofitting design approach for strict life-cycle net-zero buildings is still quite rare. The innovation of this study is to propose an integrated design process to determine optimal retrofitting solutions and achieve life-cycle net-zero. The retrofitting also aims at maximising lifetime payback cost by selecting appropriate installation areas or capacities of each renewable energy device. A real-world office building is adopted as a case study to demonstrate the proposed retrofitting design approach, while 5 different sceneries are adopted to demonstrate different retrofitting situations. The maximum lifetime payback cost reduction would be 116.3% and 103.5% for life-cycle net-zero energy and carbon for this case study building. The proposed integrated design process can be applied to different types of buildings to transform them into truly carbon-neutral and consequently mitigate climate change-related issues.