What makes a building “the best”?
For decades, architecture awards have been shaped primarily by design quality, cultural value, technical achievement and the experience of the finished space. Those measures still matter.
But they are no longer enough.
A building can be visually outstanding, socially useful and technically sophisticated while carrying a substantial climate footprint through material extraction, construction, operation, maintenance, refurbishment and eventual demolition.
That is why RIBA’s decision to publish whole-life carbon data for the six projects shortlisted for the 2026 Stirling Prize is significant.
The move follows a campaign by the Architects Climate Action Network, called “Less Taste: More Metrics”, which argued that environmental information should be transparent and central to judging the UK’s most prominent architecture award.
RIBA had already collected embodied-carbon information from all entries. The change is that shortlisted projects’ data will now be released publicly ahead of the October ceremony.
This is more than an awards-story development.
It reflects a deeper shift in the built environment: carbon data is becoming part of how clients, investors, insurers, occupiers, planners and the public define quality.
Whole-life carbon changes the question
Whole-life carbon captures the greenhouse-gas emissions associated with a building across its full lifecycle.
It usually includes:
Upfront emissions from raw materials, manufacturing, transport and construction
Operational emissions from energy use during occupation
Emissions associated with maintenance, repair, replacement and refurbishment
End-of-life emissions from demolition, disposal, reuse or recycling
In some cases, benefits associated with material reuse or carbon storage
In simple terms:
Whole-life carbon=upfront carbon+operational carbon+use-stage carbon+end-of-life carbon
This matters because a highly energy-efficient building can still have a large upfront carbon footprint if it uses carbon-intensive
materials or requires extensive demolition and reconstruction.
Conversely, retaining and adapting an existing building may preserve significant embodied carbon even if the design challenge is more complex.
The question is no longer simply, “How efficient is the building once it opens?”
It is also, “What did it cost the climate to create, maintain and eventually replace it?”
Why public disclosure matters
Carbon data that is collected but not shared has limited power to change decisions.
Transparency creates comparison. Comparison drives learning. Learning can improve specifications, procurement, design briefs and future project choices.
The campaign behind RIBA’s decision makes a straightforward argument: architecture awards influence culture. They signal what the industry celebrates, what clients aspire to commission and what younger designers are encouraged to value.
If awards elevate visual impact without clear environmental metrics, they risk telling the market that carbon performance is secondary.
If they publish the data, they create a more honest conversation.
The goal is not to reduce design to a single number. Buildings are complex. Context matters. Different project types have different constraints, uses and heritage considerations.
But complexity is not an argument for opacity.
Whole-life carbon data should be interpreted carefully, using consistent methods and relevant benchmarks. It should sit alongside social value, accessibility, biodiversity, resilience, adaptability, cost and design quality. It should not be ignored.
The data is becoming a commercial requirement
The RIBA announcement comes at a time when whole-life carbon is moving from specialist practice toward mainstream business discipline.
Developers increasingly face carbon-related questions from investors and lenders. Public-sector clients are embedding carbon requirements in procurement. Large occupiers are demanding better environmental data from landlords and supply chains.
Planning authorities are developing whole-life-carbon policies. Corporate reporting and green-finance frameworks are creating new expectations around climate data and transition planning.
For project teams, this changes the role of carbon measurement.
It is no longer a final-stage reporting exercise.
It needs to influence decisions from the earliest project stages:
Whether to retain, refurbish or demolish existing structures
The structural system and material palette
The source and quantity of steel, cement, aluminium, timber and finishes
The durability and repairability of components
Construction logistics and waste management
Future flexibility and adaptability
Operational energy design
Deconstruction, reuse and circularity options
The most valuable carbon information is information available early enough to change a decision.
Carbon data needs governance
Publishing a carbon number is not the same as producing a reliable carbon number.
To be decision-useful, whole-life-carbon information needs clear boundaries, recognised measurement methods, source data, assumptions, version control and accountability.
A robust process should answer:
Governance question | Why it matters |
|---|---|
Which lifecycle stages are included? | Prevents misleading comparisons between projects with different boundaries |
Which carbon-assessment methodology is used? | Supports consistency and credibility |
Are material quantities based on design estimates or verified records? | Clarifies the reliability of the calculation |
What emissions factors have been applied? | Enables users to understand the source and age of underlying data |
How are reuse, recycled content and biogenic carbon treated? | These choices can materially change results |
Who has reviewed the calculation? | Independent review improves confidence |
When will the data be updated? | Carbon estimates should evolve as design and construction information becomes more precise |
This is where whole-life carbon becomes an evidence-architecture issue, not just a sustainability metric.
Design quality and carbon quality can reinforce each other
The debate should not be framed as aesthetics versus carbon.
The best architecture has always involved working intelligently with materials, climate, place, function and time. Whole-life carbon can strengthen that tradition by making material consequences more visible.
A lower-carbon building may use less material, retain existing structures, prioritise adaptable space, make better use of daylight, select durable components and design for disassembly or reuse.
These are not necessarily compromises.
They can produce buildings that are more flexible, more resource-efficient, more resilient and more connected to their context.
The challenge is to make sure design teams are rewarded for making those choices.
The next standard for the built environment
RIBA’s commitment to publishing the Stirling shortlist data should be seen as a starting point rather than an endpoint.
The next step is to make whole-life carbon a normal part of project evaluation—not a special feature for awards, flagship buildings or sustainability reports.
Clients should ask for it at briefing stage. Designers should use it to test options. Contractors should provide better material evidence. Lenders and investors should understand what it means for risk and asset value. Public bodies should use it in procurement. Awards should publish it transparently.
A building cannot be judged only by how it looks when it is complete.
In a carbon-constrained economy, it must also be judged by the emissions created across the life it will live.