Harnessing data to build circular cities

Author: Ben Cartwright

The data revolution

For several years now, the world has been in the midst of a data revolution, with the capability to measure and monitor all aspects of our world, both physical and intangible, increasing every day. The last 20 years have seen staggering increases in the volume and detail of data being collected, thanks largely to the advancement and falling costs of digital technology. While cases of data misuse and invasion of privacy make it a contentious issue, this revolution has nonetheless positively reshaped our understanding of the world around us. Most significantly by helping researchers, businesses, policymakers, and civil society identify solutions to some of the world’s biggest problems.

How data can help address high levels of resource inefficiency in the built environment

An industry with high levels of resource inefficiency that stands to benefit greatly from making full use of data’s potential is the built environment. Globally, the construction of buildings and infrastructure is associated with billions of tonnes of carbon emissions annually, extensive land-use change, massive water consumption, air and water pollution, and numerous other negative environmental outcomes. In the EU alone, roughly 374 million tonnes of construction and demolition waste was created in 2016 [1]. Global primary materials use is projected to almost double from 89 billion tonnes in 2017, already an unsustainable level, to 167 billion tonnes in 2060 [2]. These shocking figures are among the reasons that compelled CIRCuIT’s 29 partners from four cities and regions to work collaboratively to address these global issues. According to the United Nations’ International Resource Panel, increasing material efficiency in the construction, operation and dismantling of homes could reduce total carbon emissions by up to 70% in some regions by 2050 [3].

Though they serve as a powerful call to action, high-level figures such as those provided above tell us little about how to find practical solutions to these issues. For this, we need precise, high-quality data which shows us exactly what materials are going into and coming out of the built environment at the level of cities, districts, and even neighbourhoods, and the paths they take before construction and after demolition. With that kind of data, we can compare scenarios and model optimal interventions consisting of approaches such as urban mining, adaptive reuse, and design for flexibility and disassembly, for use by policymakers and practitioners. Taking into account that there is rarely a one-size fits all approach, it will be essential to gather detailed data from different countries, cities, districts, and neighbourhoods in order to find the varying combinations of approaches that will provide optimal solutions for each context.

Mapping the flows of materials to create circular cities

Mapping the flows of materials is the focus area of the CIRCuIT project which aims to harness data’s potential. This focus area identifies and exploits relevant data to support the targeted trialling of practical techniques, to feed into visualisation of current and future built environment circularity and benchmark the progress. Additionally, it is advancing the critical goal of understanding what further capture, and utilisation of data is necessary to support circular action.

The first task within this focus area, which largely took place from July 2019 to February 2020, was to undertake a thorough mapping exercise for any relevant data across the four partner city regions of Copenhagen, Hamburg, Helsinki, and London. Primarily, the goal was to form a detailed, granular understanding of the stocks of construction materials within the built environment, as well as the material flows into and out of the built environment (e.g. via supply chains, waste management, circular flows), and the many factors that influence these. To date, we have identified a huge volume of data, along with many exciting use cases that are in the initial stages of implementation throughout the project.

We have also highlighted the characteristics and shortcomings of the four city regions’ data ecosystems. Currently, data is gathered and held by a wide range of actors, each looking at a slightly different aspect of the subject, using different data collection methodologies, units of measurement, and file formats. In many cases, there are whole sections of material chains within a city or region for which there seems to be no data collected at all. Often, the relevant data will be collected and held privately by organisations with no intention of making it publicly available. The diagram below depicts a range of potential points of data capture; our findings show that there is huge variability in volume and quality of data captured between each point, and across the cities.

A data led approach to construction is on the way

Though its foundations are still under construction, the future is looking up for data capture in the built environment, as increasingly powerful analytical methods mean that data-driven insights are improving all the time. It is encouraging to see the often-lagging construction industry increasingly entering the world of Industry 4.0, with developments within planning policy as well as advancements in Building Information Modelling, Internet of Things, remote sensing, machine learning, big data analytics, pre-demolition audits, blockchain, and many others promising better capture and application of data than ever.

Look out on this website for an upcoming publication of our findings so far. During the course of CIRCuIT, we will look into how to embed improved built environment data capture into policy and practice, we will develop a range of ‘circularity indicators’ from material-level up to the city-level, and we will be supporting other work packages in using data to advance their aims and objectives.

References [1] Eurostat (2019), Generation of waste by waste category, hazardousness and NACE Rev 2 activity.

[2] OECD (2019), Global Material Resources Outlook to 2060: Economic Drivers and Environmental Consequences. OECD Publishing, Paris, France. [3] International Resource Panel (2020), Resource Efficiency and Climate Change: Material Efficiency Strategies for a Low-Carbon Future. Hertwich E, Lifset R, Pauliuk S, & Heeren N. A report of the International Resource Panel. United Nations Environment Programme, Nairobi, Kenya.