Bridging the sustainability gap between building design and operation

Across the built environment, sustainability certifications have become a hallmark of good intent. But what happens when good intent doesn’t translate into good performance?

Recent policy moves - like the City of London Corporation’s requirement for five-star NABERS ratings on new office developments - signal a vital shift. Performance in operation is now non-negotiable.

At BFY Carbon Strategies, we’ve been investigating this misalignment using publicly available data, and what we found is alarming. A review of the BREEAM Projects Database revealed:

• 18,383 total certifications listed
• 17,322 are pre-construction or in-design
• Only 1,061 are in-use or post-construction certifications
• 465 projects achieved 'Outstanding' at the design stage -but only 4 (0.02%) earned 'Outstanding' in-use

In this article, we explore why the gap between design and operation exists, what recent policy shifts mean for the industry, and how developers can ensure buildings perform sustainably in use.

Intent without accountability is not enough

This isn’t a discredit to BREEAM. It’s a globally respected framework that lays a solid foundation. The problem lies in how the industry applies it - or rather, stops applying it - once the design phase is over.

Far too often, developers, consultants, and project teams celebrate a design-stage certification as the final milestone. But performance doesn't live in the drawings. It lives in:

• How the building is installed and commissioned
• Whether energy systems are configured for actual use
• The training of operational teams to run the building efficiently
• And most critically, whether the design intent is contractually protected through to handover and beyond

When these steps aren’t governed, tracked, or enforced, the result is predictable: buildings underperform. Certification becomes symbolic. And energy bills, emissions, and occupant discomfort tell a very different story from the design-stage brochure.

No performance governance means no performance outcome

Not only does this disconnect put reputations at risk, it puts Net Zero Carbon (NZC) targets out of reach too. Buildings being constructed today are meant to operate well into 2050 and beyond. If they can't meet today’s operational benchmarks, how will they perform under tomorrow’s regulations?

Without post-construction validation, the ESG narrative falls apart. Energy Use Intensity (EUI) targets go unmeasured. Whole-life carbon tracking becomes guesswork. And asset managers are left scrambling when actual energy consumption blows past what the model predicted.

What can developers and advisors do differently?

1) Set Non-Negotiable Performance Outcomes Early

Design for a clear operational EUI and make that a contractual requirement.

2) Mandate In-Use Certification

Whether BREEAM In-Use, NABERS, or another framework, performance must be verified post-occupancy.

3) Bridge Teams Across the Lifecycle

Ensure your design consultants, contractors, FM providers, and ESG advisors are aligned from RIBA Stage 1 to operational handover.

4) Don’t ‘Value Engineer’ Performance Away

Cost savings should not come at the expense of system integrity or long-term energy use.

5) Apply Governance to Commissioning and Handover

Ensure systems are set up and tuned for optimal efficiency before tenants move in.

It’s time for change

The tightening of operational performance standards, like the City of London’s NABERS policy, is just the beginning of a market shift from designed-to-perform, to proven performance.

At BFY Carbon Strategies, we work with real estate developers, owners, and investors to embed carbon and energy governance throughout the lifecycle - from vision to operation. We believe sustainability isn’t awarded at design, but earned in use, through the delivery of buildings that actually perform.

For more on how we can accelerate the performance of your next project, contact Luke McQuire.