New brief: How to Assess Circularity in the Urban Built Environment

Traditionally, the construction sector has followed a linear ‘take–make–dispose’ model, significantly contributing to resource depletion and waste generation. The Circular Cities and Regions Initiative (CCRI), supported by the European Union within the framework of the Circular Economy Action Plan, brings together several existing initiatives and tools to support the circular economy across different levels of the built environment. Guiding tools for circularity in the urban built environment emphasise the importance of Life Cycle Thinking (LCT) and a multi-stakeholder approach.

At its core, circularity aims to keep resources in use for as long as possible, extract maximum value from them, and recover materials at the end of their life so they can be reused, repaired, or recycled. However, we need ways to assess the potential impacts and benefits of circular solutions on the urban built environment. This is where circularity assessment frameworks and indicators come in.

Five DUT projects pointed out to key considerations in circularity assessments 

1. Existing circularity frameworks tend to focus primarily on the building scale, often overlooking interactions between the buildings and their surrounding context, as well as larger territorial scales such as districts and entire cities. A multiscale perspective that assesses performance across buildings, neighbourhoods, and cities should be preferred to capture systemic impacts and trade-offs.
2. Most existing indicators focus heavily on environmental aspects. A key priority is therefore the development and testing of integrated indicator sets that capture environmental impacts (e.g., lifecycle-based emissions, resource efficiency, waste prevention, circularity performance) alongside socio-economic and quality-of-life dimensions, including social acceptance of reused materials, and impacts on vulnerable groups.
3. Third, it is important to define the robustness of the indicators and how we could assess how robust different indicators are. Robust indicators should be based on sound methodologies, consistent data sources, and clearly defined system boundaries, ensuring that results are comparable and suitable for informing policy and decision-making.

Types of circularity assessments and best practices

Many quantitative methods rely on Life Cycle Assessment (LCA), a standardiszed method that evaluates environmental impacts throughout the life of a building or construction project. LCA-based indicators are especially common for assessing emissions, energy use, and resource depletion (e.g., Global Warming Potential).

Some quantitative indicators aim to summarise circularity in a single score, such as the Building Circularity Index (BCI). These indicators typically combine data on material inputs, waste outputs, lifespan, and design-for-disassembly features into one value. While convenient for comparison, such composite indicators can hide important details and assumptions.

Best practice: 

"Quantitative indicators are most useful when calculation methods, system boundaries, and data sources are clearly defined and transparent."

Semi-quantitative methods often rely on binary scoring (yes/no) or ordinal scales (e.g., 0–5). They are especially useful for aspects that are hard to measure precisely, such as design quality or management practices. However, these methods and respective indicators can be subjective if scoring rules are unclear or depend heavily on expert judgement.

Best practice: 

"Use well-defined scoring criteria and document how scores are assigned to improve consistency and repeatability."

Qualitative methods are particularly important for social, cultural, and managerial dimensions of circularity, which are often overlooked but critical for real-world implementation. However, qualitative methods are less easily standardised compared to quantitative ones. Given the relatively high degree of interpretation, achieving comparable assessments can be challenging. Nevertheless, they provide essential context and highlight enabling conditions for circularity.

Best practice: 

"Use qualitative indicators alongside quantitative ones, not as replacements, to capture the full picture."

By using circularity indicators thoughtfully – as part of an integrated, multi-dimensional assessment – stakeholders can better understand where improvements are possible and how the built environment can shift from a linear system to a truly circular one.

This publication includes nineteen recommendations for circularity developers in different areas such as:

• Urban policymakers and public authorities responsible for planning, regulation, and investment decisions in the built environment at local, regional, and national levels.
• Urban planners involved in designing and implementing circular solutions across buildings, neighbourhoods, and cities.
• Practitioners and technical experts in the built environment including architects, engineers, and sustainability consultants applying circularity assessment frameworks and indicators in practice.