New requirements for the top ratings such as BREEAM Excellent and Outstanding, and LEED Gold and Platinum can drive market-leading improvements.

For example, McKinsey’s renovated Boston office achieved LEED v4 Platinum after integrating a best-in-class energy efficiency strategy into design specifications, including an air-tight exterior envelope, state-of-the-art HVAC, and architectural features that optimized natural light and increased fresh air circulation by 30-50%.

While this project was certified under LEED v4, the same type of innovative, proactive strategies will be required for v5, says Dum.

Powering buildings and operations on clean energy is another area in focus for top ratings, supporting the transition to 100% renewable energy that one in ten corporates have committed to.

“BREEAM ‘Excellent’ typically reflects the top 10% of certified buildings, and ‘Outstanding’ the top 1%—but in my experience, the proportion of projects targeting these ratings was much higher. These changes help reset the significance of the top ratings,” says Ramsey.

Yet the measures now needed to obtain certification under the newest versions of the ratings systems may increase upfront costs and technical complexity. LEED and BREEAM award points for advanced HVAC systems that adapt to fluctuating energy demands, significantly reducing operational carbon emissions. Both frameworks also recognize and incentivize the use of construction materials with minimal embodied carbon footprints. This can require organisations to rethink procurement strategies to source new equipment and materials.

However, the pay-off for low-carbon buildings is substantial and must be considered alongside capital expenses at the onset of a project. “Implementing new certification requirements shouldn’t be viewed as a barrier, but instead as a value-add,” says Dum. “Our projects typically lead to increased operational savings due to improved efficiency. Attaining LEED or BREEAM certification can also mean buildings ultimately become more valuable with stronger tenant appeal and higher premiums.”

Across global markets, JLL Research has found evidence of green rental premiums ranging from 7.1% to 11.6%. As green building certifications become increasingly stringent, newer versions are poised to provide a more robust measure of an asset's sustainability performance relative to the broader market, with higher ratings more likely to command increased premiums.