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‘The planners were bemused why we wanted to keep it’: the clients championing retrofit

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Behind every well-designed retrofit project is a savvy developer. We spoke to some of the latest RetroFirst signatories about the benefits and challenges of reuse on a selection of their key schemes

Juliette Morgan, head of sustainable development, British Land

Developer British Land
Architect Arup
Scheme 1 Triton Square (pictured above

Tell us about the project
1 Triton Square is part of British Land’s Regent’s Place campus in London’s West End and was originally designed in the 1990s by Arup Associates. As customer needs have evolved, we worked with Arup and Lendlease to transform the building for today’s modern workstyles. 

We took a circular-economy approach from the outset, asking ‘how much can we retain and reuse?’ The team rose to the challenge, retaining as much of the existing façade, substructure and superstructure as possible while adding three floors and doubling the lettable office space. 

The £196 million redevelopment, due to complete next year, comprises 29,000m2 of office space and features a large atrium, five terraces and 2.7m-high floor-to-ceiling windows, filling offices and stairwells with natural daylight. There are 22 new-build affordable flats adjacent to the site, with public-realm improvements including enhanced greening around the perimeter, benefiting the wider Camden community. 

What were the challenges of the existing building?
To meaningfully improve the building’s sustainability performance, the team looked at every aspect of the project to save carbon and cut waste. Instead of scrapping the original façade, the team removed 3,500m2 of panels, which were transported to a pop-up factory nearby, inspected, deep-cleaned, refurbished and reinstalled.  

Was demolition or partial demolition ever considered?
The original building was high quality and had capacity to take more space, so demolition made little sense. We wanted to save material while minimising our environmental impact.  

What other aspects of your design reduce the building’s whole-life carbon impact?
We replaced over 70 per cent of the required cement with blast furnace slag, which has about half the carbon of standard concrete. Operational energy efficiency improvements were achieved by positioning corner stair cores outside the building’s thermal line with nominal heating for frost protection, improving air tightness and energy efficiency. 1 Triton Square’s operational carbon saving versus a typical commercial building is 43 per cent, averting 34,690 tonnes of CO2 emissions over the next 20 years. The building has saved around 56 per cent embodied carbon versus a new build, averting 27,463 tonnes of CO2 emissions during construction.  

What skills do you look for from an architect on a retrofit job?
Architects who think differently and challenge us to be as sustainable as possible in our approach. Our tender process often involves a design competition or panel, but sometimes we will select a partner we know to have a particular set of skills. 

We wanted to leverage Arup’s multidisciplinary team, including their engineering and sustainability expertise, which would usually have been provided by separate partners. This meant we operated as a cohesive team.  

What were the main lessons learnt from the project?
By challenging standard approaches to refurbishment and reusing existing materials and components we can minimise embodied and operational carbon, reduce costs and expedite development processes. This truly collaborative approach to development, involving all partners from the early stages, has yielded positive results. 

We are incorporating circular-economy principles into plans to transform Regent’s Place’s public spaces and looking at how much of the façade can be recycled on another British Land development.

Richard Upton, chief development officer, U+I

Mayfield planned

Mayfield planned

Developer U+I 
Architect Studio Egret West 
Scheme Mayfield Depot, Manchester 

Tell us about the project …
The former Mayfield station, the cavernous depot and the imposing red brick railway arches, are an integral part of our £1.4 billion transformation of Mayfield in Manchester, the long-derelict site next to Manchester Piccadilly. 

This phased regeneration comprises 1,500 homes, around 150,000m2 of offices, two hotels, 330,000m2 of retail, culture and leisure facilities, all centred on Manchester’s first new park in 100 years. It will take 10-15 years to complete. 

But the business of creating a new place is already underway and our decision to retain these old industrial buildings is integral to this as it has allowed us to create Manchester’s newest cultural venue, Mayfield Depot, which last year attracted over 330,000 visitors to the site. 

Was demolition or partial demolition ever considered?
Yes, but not by us. When we pitched for the project, the brief was to demolish all the old railway buildings and replace them with a straight connection to Piccadilly station – light, bright and brand, spanking new. 

It was easy to understand why. The depot had been abandoned for decades and had become widely associated with degradation, drugs and prostitution. But we dug our heels in. The depot is not just any old building. It has a history dating back to 1910, was a functioning station until the early 60s and used by the Royal Mail as a distribution hub for nearly 18 years. You can’t buy that wealth of heritage. 

We were the only bidder for the project that recommended retaining the building and, happily, our partners bought into our vision. The depot is an amazing space. People walk in and go ‘Wow’. It costs a lot of money to make a ‘Wow’. But we had it right there, already – you just had to be able to see it. 

Mayfield depot before luke hayes

Mayfield depot before luke hayes

Source: Luke Hayes

Mayfield Depot, Manchester, before retrofit

What were the challenges of the existing buildings?
These are very old buildings in a bad state of decay. They have been unloved for a long time. So that comes with its challenges, particularly around the structural integrity of the buildings, but also in terms of integrating new structures within old structures. But it seems like common sense to try and keep them, spruce them up and use them in a creative way.  

What have been the main lessons from the project that you could apply on other developments?
The key takeaway is that we were able to convince our partners to embrace our vision for the site; to create a new place out of the old – a place that is true to the heritage and providence of the location – and to do that in a way that they hadn’t considered, by retaining these unloved industrial buildings that would have otherwise been flattened. 

Ultimately these are the sort of places where top hoteliers, restaurateurs and retailers want to be. These are the places that creative types gravitate towards; the old buildings with a sense of character, an authenticity and a richness that the modern equivalent seldom provides.   

Conrad Peberdy, managing director of the Ethical Property Company  

green house waugh thistleton before and after collage

green house waugh thistleton before and after collage

The Green House, before and after 

Developer Ethical Property Company 
Architect Waugh Thistleton
Scheme The Green House, east London 

Tell us about the project …
The Green House in Bethnal Green, east London, is a hybrid project. The original building was a factory built in the 1970s for the rag trade; it’s an industrial structure which had fallen into disrepair and was used for illegal raves. We refurbished the original building and then built an extension out of cross-laminated timber (CLT) – effectively doubling its size.  

What were the challenges of the existing building?
There were challenges around waste collection and security, but the biggest challenge was working out how air could be ventilated around the building. Concrete and timber have very different properties around heating and cooling, so trying to ensure an effective and sustainable system for the entire building was hard. 

Had demolition or partial demolition ever been considered?
Around 80-85 per cent of our projects are retrofit. Our company has a social mission and advocates for the circular economy so we support retrofit from a carbon perspective. But we also own a portfolio of incredibly odd places and believe historic buildings are attractive to people – so there is a commercial element too. When we developed the Green House we needed a new office space in a very short amount of time because one of our existing offices in east London, sadly, did have to be demolished. So time mattered and a new-build scheme would have taken a lot longer.  

What other aspects of your design reduce the whole-life carbon impact of the building?
The use of CLT reduced its carbon footprint by about 60 per cent compared to using concrete. And when we fitted out the interior we primarily used wood, bark and other natural products. We also have a gigantic area to the rear which is made out of recycled plastics, we have a whole roof of solar panels and we also installed green roofs. And we used a natural ventilation system – there is no air conditioning.  

Were the planners supportive of the proposals?
They loved the reuse of an existing building, but there were some issues. The planners were demanding we created turning circles for bins and deliveries to come through, but the existing building took up most of the front of the site, so it was almost like they were forcing us to demolish part of the existing building in order to extend. 

They were not really reflecting or being flexible enough about the actual constraints of that site – it was almost like their own policies were trying to force us at times to demolish, even though the planners were supportive of what we did.  

Some people might say this building is not beautiful. What would you say to them?
I can understand that some people might look at the building and think it’s a bit of an ugly duckling. What is important, though, is the quality of the space inside. I’m not an architect, I’m an operator, so it’s all about the functionality of the inside spaces. I want them to look good and I want them to reflect what our tenants want, but I’m not about building a building to make it look like a Picasso.   

What skills are you looking for when you employ an architect on a retrofit job?
What’s most important is: has our architect captured our vision for the building? Do we believe they have the practical skills and experience to deliver on that vision? And do we think that, not only have they captured our vision but they are going to turn it into something that is practical and achievable and ideally on budget and on time? It can’t be a pipe dream. 

Basil Demeroutis, co-founder, FORE Partnership

Tower bridge court before planned

Tower bridge court before planned

Source: Summit Visual (planned image)

Tower Bridge Court, London, before and planned

Developer FORE Partnership 
Architect Stiff + Trevillion
Scheme Tower Bridge Court, London, Tower Bridge 

Tell us about the project …
We are transforming a dated 1990s office building next to Tower Bridge into one of the most advanced workspaces in the UK, with a number of terraces and spectacular views. 

The £90 million project will set new standards in sustainability, health and wellbeing and social impact. By refurbishing the existing building, designed by Cecil Denny Highton, we are reusing the embodied carbon in the frame while making it net-zero carbon in operation. We have just received the planning green light, and will start on site early this year. 

What were the challenges of the existing building?
Stiff + Trevillion has designed our building to create a transition between the traditional warehouses of Shad Thames and the modern development just opposite at More London. The scheme also sits just metres from Tower Bridge and right alongside the Grade II-listed hydraulic accumulator tower which powered the bridge’s original raising system. We had to safeguard both. There are also very complicated site logistics to consider as you obviously cannot close Tower Bridge Road and there is only a narrow road behind the building. 

Was demolition or partial demolition ever considered?
We very quickly dismissed the vendor’s original proposal, which was for a new 14-storey tower on the site. We faced a similar situation on the site of our recently completed sustainable office in Manchester, Windmill Green, where there were numerous proposals to build new towers of up to 40 storeys. 

When we acquired the Tower Bridge site, planning was in place for a 17-storey building, but we opted instead for retrofit. The key driver for us is that it is more sustainable, but it is also faster, less expensive, and less complicated to build, with nearly the same economic result. 

What other aspects of your design reduce the building’s whole-life carbon impact?We all kn
ow that cement and steel are two of the worst culprits when it comes to the climate crisis. If steel was a country, it would rank number three on the list of worst emitters of CO2 behind China and the US. Cement would be fourth. We are using steel with 95 per cent recycled content. Our concrete will have 50-70 per cent cement replacement, which will lower the overall carbon content by two thirds. This approach continues with the interiors too, for example, using recycled bricks as a flooring material and wall tiles made from recycled glass. 

What have been the main lessons from the project?
Tower Bridge Court will be 100 per cent electric. It will be disconnected from the gas grid and zero carbon in operation. With clever construction, buildings do not need much heating and cooling so you can get rid of gas quite easily, and this project shows that this is achievable in a retrofit too. We need to think seriously about the way we heat all buildings if the UK is to be zero carbon by 2050.

Tim Heatley, co-founder of Capital & Centric

Shedkm bunker littlewoods capital centric

Bunker Building, Littlewoods Liverpool: before and after retrofit

Bunker Building, Littlewoods Liverpool: before and after retrofit

Developer Capital & Centric

Architect ShedKM

Scheme Littlewoods Bunker

Tell us about the project….
The £2million conversion of a long-disused storage building marked the first phase of the wider regeneration of Liverpool’s 1930s Littlewoods complex.

What were the challenges of the existing building?
This was one of our first conversions. The building was ugly and hadn’t every been occupied by people, it just stored Littlewoods catalogues. It had contaminants in the ground around it; it had little or no natural light; it was in a ‘pioneering’ part of Liverpool with no demand for work space; and values were very low so construction costs had to be minimal.

Had demolition or partial demolition ever been considered?
Yes we bought the site off the now defunct North West Development Agency and when they heard we planned to keep the keep the building, they almost refused to sell it to us. They wanted it ‘regenerated’ which them them meant knocking it down and building something new, but we couldn’t afford a new building for the budget we had - at least not one that we were prepared to put our name to. When we showed them the plans then reluctantly and nervously allowed us to buy it.

Aside from retaining the original fabric, what other aspects of your design reduce the whole-life carbon impact of the building?
We use natural ventilation and large domestic-sized gas combi-boilers to heat / cool the whole place. Utilising the high thermal mass of the concrete structure was a cost effective and low carbon way of regulating the temperature of the building. The positioning of the roof lights and the glazing all took the heating and cooling requirements into account, for example the windows are set back to allow shade in the hight of summer.

Most of the things we did were low tech and very effective but we’ve got things like low flow taps and leak detection etc, we didn’t use any renewables though. We still own the building so running costs are important to us.

Were the planners supportive of the proposals?
The planners at the time were bemused as to why we would want to keep it, why we were creating work space in that part of Liverpool and they were intrigued as to if it would ever happen. It has gone one to win RIBA, British Council of Offices and BREEAM Awards, among others

What have been the main lessons from the project that you could apply on other developments?
It is not what you’ve got, it is what you do with it. Pretty much any building can be re used. We’ve just finished opening a restaurant in a 140m² stand alone concrete building on stilts in Manchester City Centre - part of a £250million development. Work with the structure rather than fight it; don’t try too squeeze too much in; be generous with space - that’s the cost trade-off for not having to pay for a new structure. Leave as much of the building exposed and raw, it adds character and saves money. And know when to stop changing things, less is more. Differentiate between the new and the old with bold new interventions.

A big joy for me is that retrofits often don’t have to apply the same tedious, multitude of regs which means you can essentially do things that are not compromised, visually striking and fun that you otherwise wouldn’t get away with

What skills are you looking for when you employ an architect on a retrofit job?
We always back individuals, never a practice. We find great people and crap people at big and little practices. When we see something we like we ask who did, not which practice but which individuals. I think there is so much poor architecture, so many architects are rubbish at creating beautiful and practical spaces - present company excluded of course - and I know I’m preaching to to the converted amongst the AJ readership, so we have to be very careful who we back.

We always back individuals, never a practice

We put 100 per cent trust in our architects to see out their vision, so we look for someone with a big idea and an eye for detail, someone that will see a project through to the finish and someone that has done it once, on any scale, before.

It can be harder to find that talent in big organisations because everyone claims responsibility for the good stuff, but we’ve started to work with BDP recently and because we’ve got to know the individuals on our projects we have total faith in them to push boundaries and get the boring bits right too.

Bba8 bw

The bunker building before conversion.

The bunker building before conversion.

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Readers' comments (1)

  • Fascinating stuff but £196 million for a repositioning of a barely 30 year old building wow

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