27 August 2025 – The buildings and construction sector is responsible for roughly one-third of global carbon emissions and waste[1],[2]. This raises a critical question: How do we ensure that both new and existing buildings reduce negative impacts while meeting growing demands?  In this blog, Rupert Jordi, CISL Programme Manager, explores 'green' buildings, warns against conflating building certification with true sustainability, and argues the label is less important than the outcomes. 

As an architect and educator committed to delivering a sustainable built environment, I’m buoyed by an increase in circular construction, green building certification and the reuse of existing buildings [3], and I celebrate the growing social acceptance and demand for green credentials. However, despite this progress, I’m concerned by projects that exploit this demand for sustainable buildings and worry that an overemphasis on green certification distracts from delivering truly sustainable outcomes.

What is a ‘green building’?

To some, ‘green building’ is synonymous with ‘sustainable building’. Both terms have many connotations and may be perceived as ranging from greenwashing to a genuine attempt to address critical challenges. Others may find these terms idealistic or unfounded, or worry that other financial or practical outcomes are deprioritised in favour of ‘green’ features. Neither has a universal definition, though, and to many, ‘green building’ refers specifically to certified projects. Broadly speaking, a ‘green building’ should be a systems approach to design, procurement, construction, and operation that minimises the environmental impact of the built environment, improves social outcomes, protects and restores nature, and promotes circularity and resource efficiency throughout a building's lifecycle. It calls for regulation and certification to incentivise positive change across the sector and requires collaboration between public and private organisations and disruptors to innovate and increase the pace and scale of change.

The focus of this definition is on a systemic market shift toward sustainable buildings and infrastructure, and the individual and collective actions needed to achieve it.  

Green buildings and certification

Green building certifications – although varied – share a common goal: to measure and improve sustainability performance.

Green certification as we know it today emerged in the 1990s, with the launch of the BREEAM assessment framework in 1990, followed shortly by the LEED rating system. Since then, many other councils and initiatives have developed their own frameworks, each with different emphases.

These have helped drive progress, particularly in energy efficiency and carbon reduction. But they also reflect a narrow, carbon-centric view of sustainability — one that often overlooks broader social and ecological concerns. While some promote water and resource conservation or improved air quality, they tend to focus on individual buildings, rather than the surrounding urban fabric, and often fail to account for regional differences.

The evolution of certification