[Article] A framework for circular facade design: Systematic review of design strategies and performance indicators

We are designing increasingly energy-efficient building facades. But are we also designing them to last, adapt, and be reused?

Over recent decades, facade engineering has focused on improving thermal performance, reducing operational energy demand, and meeting increasingly demanding building regulations. Yet this progress creates an important challenge.

High-performance facades often combine multiple layers of glazing, insulation, metals, polymers, coatings, and adhesives. While these systems can reduce operational energy consumption, their material complexity may increase embodied carbon and make repair, separation, and reuse more difficult. Unlike building structures, facades are frequently replaced during a building's lifetime, sometimes after only 20 to 25 years.

A building may remain standing for a century while its facade becomes waste several times.

This raises a fundamental question: How can we design facades that deliver high performance today without compromising their capacity to retain value tomorrow?

In our study published in the Journal of Cleaner Production, together with @Hamad Alabdulrazzaq, @Eugenia Gasparri, and @Arianna Brambilla, we investigated how circular economy principles can become practical, measurable design requirements for building facades. Our research addresses a persistent gap between circular economy ambitions and the actual decisions made by architects and facade engineers.

Circularity is frequently discussed in terms of recycled content, material passports, and waste reduction. However, these concepts are not sufficient unless designers can determine which strategies to apply, at what stage, and how their effectiveness should be assessed. The real challenge is not defining circularity. It is making circularity measurable and actionable. We systematically reviewed 122 publications and developed a Circular Facade Design Framework (CFD-F) that connects:

• 13 facade-specific design strategies, addressing material efficiency, durability, modularity, maintenance, adaptability, disassembly, and recovery.
• Performance indicators for evaluating circularity at the material, part, and component levels.
• Five lifecycle stages, connecting material inputs and installation to service life, circular potential, and end-of-life recovery.

The framework translates three circular economy principles into practical design decisions.

1. Narrowing resource loops: Use fewer resources and use them more efficiently.

Material optimization, recycled content, renewable resources, and prefabrication can reduce dependence on virgin materials and minimize construction waste.

But material efficiency should not be evaluated independently of durability, thermal performance, or future replacement needs.

2. Slowing resource loops: Keep facade components in use for longer.

A durable facade is valuable. A durable facade that can also be maintained, repaired, upgraded, and adapted is potentially more valuable.

Modularity and standardized components can allow individual panels, glazing units, or other elements to be replaced without unnecessarily removing entire assemblies.

This shifts the design objective from simply maximizing initial performance to preserving functionality and material value over time.

3. Closing resource loops: Design for recovery before demolition occurs.

Recycling should not be the only option considered when a facade reaches the end of its service life. Accessible mechanical connections, reversible assemblies, and documented components can make disassembly and reuse more feasible. A facade assembled with permanent adhesives may perform well during its first life but create major difficulties during recovery. The connection detail designed today may determine whether a component becomes a resource or waste decades later. To explore the practical application of these principles, we demonstrated the framework using a unitized curtain wall case study.

The assessment helped identify strengths, performance gaps, and opportunities across the three circular economy principles. It illustrated how the framework can inform design choices rather than treating circularity as an abstract sustainability objective. This is an important distinction. Circularity should not be a label assigned to a facade. It should be a performance characteristic that can be assessed, improved, and eventually verified.

However, our study also highlights an essential limitation: circularity potential is not the same as demonstrated environmental benefit. A reusable facade component does not automatically produce lower life cycle carbon emissions. Actual outcomes depend on service life, maintenance, transport, recovery processes, future demand, and the number of reuse cycles achieved.

The framework has not yet undergone comprehensive practitioner and empirical validation. Further research must connect circularity indicators with life cycle assessment, economic performance, material data, and real-world disassembly outcomes. This creates an important research and policy agenda. As the construction sector advances toward whole-life carbon assessment and more explicit circularity requirements, we need to evaluate building envelopes through several interconnected dimensions:

Energy performance: How efficiently does the facade operate?

Carbon performance: What are its impacts across the building life cycle?

Circularity performance: How effectively can its materials and components retain value through maintenance, adaptation, recovery, and reuse?

These dimensions should inform one another. A facade should not be considered sustainable solely because it performs well in one of them. For architects and engineers, the implication is practical: circularity must influence material selection, connection design, component standardization, maintenance accessibility, and replacement strategies from the earliest design stages. For researchers, the next step is to establish stronger empirical evidence linking circular design choices with verified resource savings, environmental impacts, and economic outcomes. For policymakers, the challenge is to move from broad circular economy principles toward consistent, facade-specific assessment requirements.

The future of sustainable facade design is not only about reducing the energy buildings consume. It is also about preserving the materials, components, and value already invested in them. A facade should be designed not just for its first installation, but for its next use.

Should design for disassembly, adaptability, and component reuse become standard requirements in facade engineering, alongside thermal performance and embodied carbon?

Alabdulrazzaq, H., Gasparri, E., Brambilla, A., & Attia, S. (2025). A framework for circular facade design: Systematic review of design strategies and performance indicators. Journal of Cleaner Production, 536, 147140.

📘 Full article: https://hdl.handle.net/2268/337930

📚 Learn more about our research: https://www.sbd.uliege.be/

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