Date
29th August 2024
Categories

Well-structured sustainability at The Elephant, 318 Oxford Street

 

One of London’s most recent building ‘glow ups’ is at an exciting juncture. At 318 Oxford Street, alterations to the existing structure are finishing, and works on the new three-storey extension have just got under way. As we reach this major milestone, we can now share a little more on how Civic Engineers has managed to undertake this significant refurbishment in London’s centre. Simon Bennett, associate director in our London studio, shares more:

One of the most striking components about the retrofit of Oxford Street’s former House of Fraser, is how far ahead of the zeitgeist it was when conceived back in 2018. Six years ago (and I think we can agree, the world has changed a lot since then), we were instinctively putting into place designs which are now being seen as state of the art in sustainability.  

In 2018, ‘embodied carbon’ was barely a consideration beyond perhaps the most progressive developers. Marks & Spencer hadn’t disclosed any details of its now-notorious proposal for its neighbouring flagship store. The London Plan presumption in favour of retention over demolition hadn’t been mooted. 

What was plain — even then, pre-pandemic — was that Britain’s high streets were in trouble. Competition from online retailers had made the idea of a department store retailer over seven levels, as House of Fraser did at 318 Oxford Street, woefully unsustainable. 

To future-proof these buildings, an alternative purpose had to be found. It was against this social and environmental backdrop that the project team appointed to the refurbishment began to consider what to do with the 318 Oxford Street site.  

From the beginning, sustainability was at the heart of the proposals. A whole range of options were considered, including: complete demolition and new build; new build within a retained façade; a ‘doughnut’ development (keeping the outer bay of structure and demolishing the rest in favour of new construction); all the way through to refurbishment and possible extension.  

Very quickly, it became clear that refurbishment was the right approach. The structure is sound and robust; the facades are fine, and they form a major feature for the local public realm. To us, this wasn’t just a ‘sustainable’ or ‘low carbon’ decision – it was good old fashioned common sense. 

These days, no doubt, there would have been whole life carbon studies, embodied carbon audits and so on. But, fundamentally, refurbishment was the right decision. A forensic understanding of the building’s structure and having deep knowledge and experience of working with existing structures allowed our decision to be made confidently. 

With the strategy decided, we then considered what needed to be done to the department store to fit it for a sustainable use.  

The small sixth and seventh floors proved a challenge. They had been designed as ancillary to the retail and had very restricted floor-ceiling heights. We concluded that they needed to be replaced, and this gave the opportunity to consider extending the building skywards.  

To achieve this, various options were deliberated upon and some mathematics applied. Two floors was the minimum that absolutely had to be removed. Three could then be added without major works to the existing structure. Cost — and carbon — effective. However this plan still required a modicum of demolition.  

We were keen to explore how the environmental impact of our decision could be reduced. So we set about looking for ways of reusing some of the material from the demolition in the new work. This was before the Steel Construction Institute (SCI)’s steel reuse protocol was published, and long before the accompanying guidance on pre-1970s steel came out last year.  

Proceeding carefully from first principles, we undertook measures which were very similar to the eventual guidance. The result has been the reuse of some of the demolished columns in the new structure, and retaining the columns from the sixth to seventh floor in situ.  

In a landmark for the Carbon Net Zero agenda, we were also able to broker a deal to use some of the beams at FORE Partnership’s development, TBC.London, a low carbon office retrofit at Tower Bridge. The collaborative effort has been shortlisted for two BCI Awards for sustainability. 

The result is a design with a structural IStructE carbon assessment at the A/A+ borderline – incredibly hard to achieve with new build.  

When finished, the structure will be a fantastic place to work, shop and to relax. With offices, gym, retail and restaurants all in one building, this grand dame has been given her encore and a genuinely sustainable long-term future. 

Well-structured sustainability at The Elephant, 318 Oxford Street