Anupa Manewa

The Net Zero debate is getting more contested as 25% of the UK emissions are directly attributable to the built environment, and 80% of it is expected to come from the existing building stock. Hence, decarbonising the existing building stock is significant, as the domestic housing sector dominates. There is a strong connection between the UK government policies and the progression of housing retrofit. However, limited studies have reviewed this interdependency. The Stern Review validated the importance of early action on climate change two decades ago. Ever since the UK adopted a strong climate change agenda when developing policies. This study aimed to analyse the housing retrofit policy actions over the last two decades and their influence on improving the performance of the housing stock. The study is limited to analysing policy actions relevant to England, which maintains the largest residential housing stock in the UK, with 26 million homes compared with Scotland’s 2.5 million, Wales’s 1.5 million and Northern Ireland’s 0.8 million, while keeping the narrative in the UK context. The detailed policy review, along with political party manifesto analysis, was undertaken as the main data collection strategy. The data was analysed chronologically to explain the patterns and underline narratives. Findings reveal that the existing retrofit policies are not always in favour of the broader sustainability requirements of the country. Governments have changed their direction quite often and focused on short-term priorities for long-term gains. There is a critical need for robust, consistent and transparent policies (interconnected with other policies) as a long-term strategy for achieving sustainable goals.

As urbanization accelerates and climate targets become increasingly urgent, conventional centralized energy systems are proving insufficient to support the transition toward low-carbon, resilient cities. This study proposes a novel biomimetic framework for urban energy systems, inspired by the Wood Wide Web, the mycorrhizal networks in forest ecologies that enable mutualistic, decentralized resource exchange. Guided by the biomimicry spiral methodology, the ecological principles of cooperation, adaptability, and distributed resilience are abstracted into a three-layer urban energy model comprising on-site renewable generation, peer-to-peer (P2P) energy sharing, and grid integration for redundancy. The model was operationalized through Building Information Modeling (BIM) simulations comparing two urban building clusters: a conventional baseline and a biomimetic cluster anchored by a high-performance “mother tree” structure, modeled after London’s Gherkin. Autodesk Revit’s Energy Analysis, Solar Radiation Analysis, and Carbon Insights tools were used to evaluate each scenario’s energy performance, solar generation potential, and carbon emissions. Results reveal a transformative impact: cooperative energy redistribution enabled multiple buildings to reach net-zero emissions, while the mother tree intervention alone achieved a 46% reduction in annual cluster-wide carbon output. The results demonstrate how decentralized, cooperative energy systems, modeled on ecological intelligence, can enhance system-wide resilience and carbon neutrality. This research advances biomimicry from conceptual metaphor to actionable infrastructure design, offering a scalable blueprint for regenerative, climate-adaptive urban energy systems. By embedding ecological principles into the built environment, cities can evolve into cooperative, circular systems aligned with nature’s logic and sustainability goals.

The construction industry plays a vital role in fostering sustainability through various concepts and strategies being implemented globally. Among these, Circular Economy (CE) stands out as a prominent approach to enhancing sustainability. CE aims to move the industry away from the traditional linear model (i.e., build-use-demolish) towards a more sustainable circular approach. In the built environment, the ‘Design for Deconstruction' (DfD) aims to integrate planning for a building's end-of-life disassembly and material/component salvaging into the design process, thereby promoting sustainability through waste minimisation. However, the relationship between DfD and circularity is less evident. For example, most of the literature about DfD explains the potentials of end-of-life disassembly is limited in terms of discussion on the second life (potential reuse) of those disassembled materials/components. This research aims to bridge this gap. A detailed literature review has been undertaken to establish the status of DfD within the construction industry, including principles, practices, advantages, and barriers of DfD and its contribution to CE. The findings confirm that the blurred link between DfD and CE, and the required improvements in standardisation, awareness, and deconstruction information model/databases are the key priorities to enhance the circularity through DfD.