BlueCity project in Rotterdam New York Circular City InitiativeBOX 3 BOX 4The BlueCity project in Rotterdam, Netherlands, transformed a large swimming pool into a hub for circular entrepreneurs. The retrofit includes the reuse of existing structures and materials, with the commercial wing composed of 90% reclaimed materials. In addition, circular principles were applied all through the retrofit process.26 This initiative aims to create “a city where no waste is sent to landfill, environmental pollution is minimized and thousands of good jobs are created through the intelligent use of products and raw materials.”29 The initiative estimates that $11 billion in economic benefits, more than 11,000 new jobs and the reduction of waste sent to landfill to zero can be achieved. Today, roughly 60% of the total solid waste generated in the city comes from construction and demolition alone.30In contrast, North America’s building stock, with an average commercial building age of around 30 years,27 presents challenges including suburban sprawl, fewer incentive programmes for circularity or retrofits and less stringent regulations. The region also has a higher proportion of single-family homes, complicating systems-wide retrofitting approaches. In the United States specifically, there is no national framework for end-of-life waste payment, recycling rates vary by state and landfill accounts for about 50% of municipal waste disposal.28 That said, selected incentives and reverse logistics are being implemented and initiatives such as the New York Circular City Initiative show promise. Developing regions in the Asia-Pacific experiencing rapid urbanization present a different scenario. By 2050, more than half of the global urban population is expected to be concentrated in Asia.31 Much of the current building stock in this region is young compared with North America and Europe, and new construction is often more economically viable than retrofits. While countries in Europe are poised for a renovation wave, similar large-scale efforts in Asia may take longer to emerge. However, the region has an opportunity to establish a foundation for circularity now. Economically advanced cities in countries such as China, Japan, the Republic of Korea and Singapore already collect 100% of waste and have achieved high recycling rates.32 Shanghai launched a three-year initiative aimed at reducing the construction sector’s environmental footprint.33 The building stock in the Middle East is characterized by a diverse mix of traditional and modern structures, reflecting the region’s rapid urbanization and economic growth. Countries such as Qatar, Saudi Arabia and the United Arab Emirates (UAE) have experienced growth in high-rise buildings and large-scale commercial developments, driven by economic prosperity and ambitious urban planning initiatives. These modern structures often incorporate advanced engineering and sustainable design principles, with varying levels of focus on retrofitting. For example, Dubai aims to retrofit 30,000 buildings by 2030.34 Across the Middle East, continuous efforts are being made to divert waste from landfill. Specifically, in the UAE, a Circular Economy Council was established in 2021 to promote sustainable practices. Increasing mandatory waste segregation and raising awareness of waste costs could accelerate circularity in the region. In many African countries, a substantial proportion of the building stock comprises informal settlements and low-rise construction, for example in urban areas experiencing a rapid annual population growth rate of 1.1% (compared with 0.3% in other regions).35 Despite efforts to improve the quality and sustainability of the building stock through various national and international programmes, additional investment in dedicated socio-economic programmes and infrastructure is needed. The building stock in Latin America is undergoing transformation through urban renewal projects and sustainable construction practices including retrofitting of existing structures. Incentive programmes encourage stakeholders to eliminate low-quality housing, reduce CO2 emissions and improve sewage treatment. Despite these initiatives, overall retrofit maturity remains comparatively low because of fragmented supply chains and variable regulations. These disparities underscore the opportunity for stakeholders to consider region-specific strategies to effectively implement circularity in retrofits based on local building-stock quality, evolution of cities, regulatory environments and infrastructure. Europe can serve as a model, but success in other regions will possibly require customized approaches that account for existing building stock, urban growth patterns and supporting infrastructure, among other factors. Circularity in the Built Environment: Unlocking Opportunities in Retrofits 17

Circularity in the Built Environment 2024