The building construction sector consumes significant quantities of resources, generates high levels of waste and creates many negative environmental impacts including carbon emissions. These problems are characteristic of linear value chains. In contrast, a circular economy approach to building construction has the potential to moderate these three problems. One way this can be achieved is to enable in-use building stocks as a repository of products for future reuse, sometimes referred to as urban mining. A key stage in such a shift is to be able to quantify stocks of construction materials and assess their direct reuse potential as products against criteria such as their location, age, type, and embodied carbon. The majority of studies of building stocks have focused on producing aggregated quantities of materials, regardless of the required information for assessing the potential value streams of future reuse. In this paper, a framework for spatiotemporal mapping of building structural products integrating external geometries and construction history is presented. To demonstrate its capacity, the stocks of clay bricks within the external walls of buildings are assessed where six types of buildings and four types of bricks are specified. Dimensions, weights, ages and embodied carbon of materials are estimated for case studies of three urban regions in Northern England: Manchester, Leeds and Bradford, and the results are spatially mapped for the city of Bradford. The paper provides the first systematic and comprehensive area-wide model to evaluate stocks of building structural products for future urban mining and circular economy of building construction systems.

房屋建筑部门消耗大量资源，产生大量废物，并造成许多负面环境影响，包括碳排放。这些问题是线性价值链的特征。相比之下，循环经济的建筑施工方法有可能缓和这三个问题。可以实现这一目标的一种方法是使使用中的建筑存量成为产品的存储库，以备将来重复使用，有时也称为城市采矿。这种转变的关键阶段是能够量化建筑材料的库存，并根据其位置，年龄，类型和内含碳等标准评估其作为产品的直接再利用潜力。建筑存货的大多数研究都集中在生产合计数量的材料上，无论评估未来重用的潜在价值流所需的信息如何。本文提出了一个结合外部几何形状和施工历史的建筑结构产品时空映射框架。为了证明其功能，评估了建筑物外墙内的粘土砖库存，其中指定了六种类型的建筑物和四种类型的砖。针对英格兰北部三个城市地区（曼彻斯特，利兹和布拉德福德）的案例研究，估计了材料的尺寸，重量，使用年限和材料的含碳量，并为布拉德福德市绘制了空间图。