Reflections on London's World Green Building Week (WGBW) '25

World Green Building Week (WGBW) is the world’s largest campaign to accelerate sustainable built environments across the globe, led by the World Green Building Council. This year, WGBW asked the built environment industry to consider the theme, ‘be bold on buildings’ – but how do we, or how can we, be bold on buildings in the real world?  

These questions were central to the discussion at our London office’s WGBW event, led by moderator, Andy Crowther, Associate at Cundall, and panellists Peter Fisher, Director at Bennetts Associates, AJ Farrant, Sustainability Manager at Landsec, and Michael Williams, Principal Engineer at Cundall. Using recently completed project, 5 New Street Square, a prime office building in London, as a practical example of ‘retrofit in the real world’, the panel considered the key drivers for retrofit, its greatest challenge, and largest benefit, fuelled by live poll results voted by attendees in the room. Andy did note at the beginning that although the case study used for the discussion is a commercial property, many of the points raised are applicable to other sectors and will feed into conversations on other projects.

Before the panel discussion, Andy set the scene with a short keynote speech, discussing the current retrofit landscape, including different legislations driving the net zero carbon agenda, and addressed the differences between retrofit and decarbonisation. Although often used interchangeably, it’s worth noting that decarbonisation, as the name suggests, looks at carbon reduction only, where retrofit considers carbon reduction as well as the long term demand for energy. He also touched upon the benefits of retrofitting, however, these were reasoned in greater detail later, during the panel discussion.

Below we will look at the live poll results and will depict the key takeaways from the session.  

Key drivers for retrofit  

The first part of the conversation was around the key drivers, asking the audience ‘what do you see as the key driver for retrofit’ via the live polling app.

Five options were presented, and interestingly, asset value/rental yields by far outweighed net zero carbon (NZC) commitments that came in third place. The latest edition of the RICS Valuation – Red Book Global Standards  - Part5: VPGA 8 (Part 3.7.4 Environmental) references that whilst ‘the pace at which sustainability and ESG is impacting valuation judgements directly or indirectly has jurisdictional variations’ there are several factors, in relation to real property interests, that should be considered. Those would include; energy consumption (with reference to heating, cooling and lighting), labels and certificates (eg BREEAM, LEED, WELL), and emissions pathways analysis eg CRREM. From a panel perspective, ‘optimisation’ was a prevalent consideration.

Greatest challenge to retrofit

The conversation naturally moved on to challenges when it comes to being bold on buildings and choosing retrofit route instead of another. The audience, mainly a mixture of architects, developers, and contractors, was asked to rank five options from most challenging to least in terms of challenges they have experienced or are expecting to see when it comes to retrofit.  

Unsurprisingly, cost remains a key hurdle and a major factor to the growth of NZC in the UK. However, challenges presented by tenants in situ came a close second and it was a great opportunity for the panel to discuss 5 New Street Square that was delivered with no disruption or loss of service provision to the tenants who remained in the building whilst the works were completed.

What is the largest benefit of retrofit?  

As mentioned before, Andy already presented some of benefits, however, we were keen to understand what the audience sees as the greatest advantage of retrofit.

Operational cost reduction and increased asset value were deemed the greatest benefits taking the first and second spot respectively as the highest voted answers, whereas social value, ESG and wellbeing faired surprisingly lower on the scale. These results sparked a lively debate as part of the audience Q&A session, highlighting that the project teams, and therefore our industry more generally, has the greatest power to drive change and lead with a people first approach, contributing to the monetary benefits.

The audience Q&A, influenced by the panel discussion and some of the questions from attendees created a great conversation touching upon many topics, including Building Safety Act and landlord versus tenant experience. On the latter, a crucial point was made that not every tenant wants mixed mode ventilation, something that not every landlord is willing to accept.

The conversation does not stop here

As part of the keynote speech, findings from Deloitte’s recent survey ‘Sustainability Signals’ were discussed where 65% of respondents agreed that climate change is an emergency, however only 37% of respondents considered their companies to be doing enough.  

Significant challenges exist across the built and natural environment, not only do we need to adapt to tackle climate change, but we also need to build for temperatures in the future as noted by our panellists. 

We would like to express our thanks to our panellists, AJ, Peter and Michael, as well as Andy for driving the conversation, as well as to the audience for their involvement and discussions raised.

The conversation does not stop here. As noted before, our industry has a great power to drive change, so how do you think we can be bold on buildings?