Sustainable architecture: build less, retrofit more, say experts

If university estates want to commit to the fight against climate change, they should be focussed less on carving out the land for new-builds and more on regenerating and retro-fitting stock, say experts in sustainable architecture

Ask Fionn Stevenson, professor of sustainable design at the University of Sheffield’s School of Architecture, what she thinks sustainable architecture is and she’s quick to respond with what it isn’t:

“It’s not net-zero carbon architecture, that’s a myth I’d like to bust – it’s much wider than dealing with the climate emergency and zero carbon. It’s about regenerating places, physically, socially, economically. Sustainable architecture is a very inclusive definition that means understanding that whatever we do in construction sits within an ecosystem”

In this respect, Stevenson says, a number of universities have actually been setting very good examples, and for decades.

Her standout example, and one she regularly takes her students on field trips (more recently for obvious reasons, video visits), is The University of Nottingham’s Jubilee campus (Hopkins Architects, 1999).

“Jubilee really treats the idea of architecture as something that needs to be part of a bio-regional masterplan, taking account of the local geology, the local ecology, the local flora and fauna. All the aspects that make up sustainable design”.

Myth-busting: Professor Fionn Stevenson


Among the admired features of the now quarter-century-old Jubilee campus were the naturally ventilated lecture theatres and the extensive use of timber structures and cladding.

Timber frames and insulation providing materials such as straw are some of the oldest, and most sustainable, construction materials in the book. But, with exceptions such as the Enterprise Centre at the University of East Anglia (the first office building in the UK to get thumbs aloft accreditation from the Passivhaus Trust), Fionn worries the plot has been lost.

“Since the invention of the steam engine, we’ve become conditioned to build in relation to cheap energy, cheap resources that we take out of the ground but really should be staying in the ground. Our forebears had no option, because they couldn’t extract the oil from the ground, they had to think about minimising resources, adopting a bio-regional approach, and local sourcing. We’ve forgotten all that. We’ve forgotten how to use natural daylight, how to do shading properly – these are simple design elements that seem to have been lost. What we have now is walls and walls of plate glass.”

Architect Ian Whittle, associate partner with FaulknerBrowns, which works closely with higher education institutes, says it’s impossible to avoid the conclusion that, “…we simply need to build less. We need to make much better use of the buildings and places we already have, and re-engineer them to radically increase their value and reduce their energy use. This is increasingly a critical part of our work with universities.”

From the moment a local dignitary plants a ceremonial shovel into the soil, the process of carving out carbon-sucking vegetation begins. There’s a compelling argument for designing in roof gardens for new builds – and repurposing the roofs of buildings undergoing retrofits – to replace the ground that was originally cleared for construction, albeit a few storeys higher.

We simply need to build less. We need to make much better use of the buildings and places we already have, and re-engineer them – Ian Whittle, FaulknerBrowns

Sounding that clarion call the loudest is Dr Benz Kotzen, landscape architect and associate professor in the School of Design at the University of Greenwich.

“We need more roof gardens,” enthuses Benz. “What’s the point in just having a building with a roof and walls? They’re, basically, just there as a rain screen. Walls and roofs could actually be doing so much more. They need to have a secondary function, right?”

Greenwich’s Stockwell Street campus has 14 green roof spaces with a mixture of uses, from research, to leisure, to teaching, to market gardening. “But aside from all of that,” says Benz, “they basically protect the building, they create thermal efficiency, they hold water in the substrate of the earth on the roof, the plants that grow there are creating humidity, they’re cleaning the air, so a roof garden is the very definition of an ecosystem service [a positive benefit that wildlife or ecosystems provide to people] and, ergo, sustainability.”

A green roof at the University of Greenwich’s Stockwell Street campus


The Greenwich roofs are an extraordinary and quite beautiful – a little surreal, too – vision of what could be quite reasonably achieved across entire cities. “We’ve got aquaponics, we’re growing plants and fish together in a symbiotic relationship. We have ducks flying in to use the ponds, we even have foxes coming to visit”. Garden birds nest throughout the gardens, insects thrive and there’s also some particularly good honey being produced by the rooftop bee hives.

If they were more widespread – if institutions were encouraged and rewarded for installing them, then, reasons Benz, roof gardens could be successful in tackling a number of environmental woes including the Urban Heat Island Effect, where even small rises in inner city temperatures lead to respiratory problems and hospitalisations.

He’s adamant that all university campuses – like Bristol, for instance, with three impressive sky-high gardens and more to come – should start greening suitable roofs to lead the way for their home cities. “Even with the garden roofs we already have, we can see how they improve wellbeing, just by being there, that’s beneficial in attracting and retaining students”.

No longer an abstract concept, ‘wellbeing’ is the go-to requirement – talked about almost as if it were a physical material – of sustainable architecture in higher education. “Most universities recognise the critical contribution student and staff wellbeing makes to their success,” says Ian Whittle, “so it’s really important that we take an evidence-based approach to designing for wellbeing and sustainability”.

To those ends, one of the key philosophies FaulknerBrowns subscribe to is the New Economics Foundation’s ‘Five Ways to Wellbeing’ framework.

This, says Ian, identifies key behaviours proven to benefit the mental health and outlook of a campus.

“‘Connect’, ‘Be Active’, ‘Take Notice’, ‘Keep Learning’ and ‘Give’… Whenever we’re designing campus facilities these are an important reference point. By thinking about how the spaces we make can positively influence wellbeing it helps us to deliver spaces and places which help people to do better, and will be valued and cherished by those who use them.”

For Ian, that’s ‘sustainability’ in a nutshell. “Designing buildings which promote movement, for example by encouraging people to take the stairs rather than a lift, is a simple way in which we can harness the benefits of an active lifestyle”.

Estate managers are making efforts to do the right thing, but they’re hamstrung by building regs which need to be updated – Professor Fionn Stevenson, University of Sheffield

Wellbeing, says Benz Kotzen, can also be achieved by bringing the outside inside.

“We’re integrating sophisticated technology with buildings that can really help with energy-efficiency but I think we also really need to be integrating nature with buildings – I mean, we don’t just need sustainable buildings, we need buildings that are good for people.”

The landscape architect cites biologist Edward O Wilson’s theory of biophilia as an idea that can be made manifest in the construction of new and retrofitted sustainable campuses.

“It’s basically the idea that humans are genetically predisposed to nature. We need it, we crave it, even if we don’t know why, in our lives. There’s research that’s found that hospital patients that can see a tree from their bed are discharged earlier. Nature is essential and it should be an essential part of our infrastructure.”

Bringing biophilia onto campus: Dr Benz Kotzen


With the biophilic effect in mind, Greenwich research into healthy work spaces has included establishing interior living walls of plants, that clean the air, and even tanks of fish. “They proved extremely popular, people really appreciated and liked and interacted with them. The fishtanks are alive and people relate to them, it’s a good example of biophilia – it’s not healthy if you divorce your life from other living things”.

Sustainability, all the experts we chatted to agreed, is a pre-requisite of any new build project. But there’s a pretty big caveat. So many UK estates have assets that stretch back centuries. Grand, historic buildings ooze the spirit and heritage of the establishment. “The very image of academia is tied to these structures,” says Ian, “they’re a vital part of an institutions’ brand, heritage and culture.”


“The older the building the less simple it is to retrofit for an energy-sustainable future”, says Fionn Stevenson.

Old buildings leak energy like hell. Retrofitting a listed library, a lecture theatre, administrative offices to make them fit for use in today’s – and, a very uncertain future’s – climate, is a monumental challenge. If universities are really serious about fulfilling the net zero commitments they pledged to fulfil over the next two or three decades, they have their work cut out.

Good systems of intelligence about a building’s energy use, will be a key weapon, says Fionn.

She says estate managers need to be able to effectively monitor their stock. Not just the building as an overall, but with sub-metering monitoring those leaky nooks and waste producing crannies, so that estates can actually work out how the different bits of the building are performing.

The ground-breaking, award-winning Enterprise Centre at the University of East Anglia and its thatched walls ©University of East Anglia 2021


In that way, argues Fionn, “estate managers can triage their sustainability strategy in terms of which parts of the buildings they need to prioritise.”

They can do that already, broadly, from what the standard building meters tell them and still tick off the requirements of the UK government’s Green Deal on retrofitting.

But looking good on paper and actually achieving meaningful results are two different things. Without detailed intelligence from a sub-metering system the result may be “a  half-baked retrofit”, albeit one that would conform to current, but less energy-efficient, building regulations.

“That’s frustrating for estate managers, they’re making efforts to do the right thing,” says Fionn,” but they’re hamstrung by building regs which need to be updated – currently those regulations are just not fit for purpose”.

Fionn says that alongside metering carried out by intelligent systems, old fashioned opinion taking is as essential to monitoring the sustainability of a building. “Estate and facility managers should be listening to the users of a building, not the client. The client is the faculty person at the top who’s signing off the requirements; the user is the poor person in the office who can’t get their window open, can’t control their heat input, and is basically really struggling.”

That said, she acknowledges, the questions asked of a building’s tenants need to be thoughtfully targeted.

“Obviously, occupants will feedback their perception, which is highly subjective. It can be skewed by things like gender and age; because men and women, older and younger people, appreciate heat in different ways, so your sampling has to be well calibrated”.

There’s an extra urgency, says Fionn. We’re in the full throes of the Covid age and she sees no signs that we can relax our guard on issues like air quality and ventilation.

“It’s never been more important to have very good indoor air quality feedback on our campuses. I’m afraid that does mean going back and retrofitting carbon dioxide monitors to every building in order to give you good intelligence.”

Universities used to be synonymous with living walls – that’s why they called it the Ivy League in America, all those famous colleges clad with creepers – Dr Benz Kotzen, University of Greenwich

Ian Whittle and Fionn Stevenson both opine that an ideal, overall metric for retrofitting university stock (alongside the already well established BREEAM standards) is the Passivhaus-recommended standard called EnerPHit – Quality-Approved Energy Retrofit with Passive House Components.

Ian Whittle suggests we look to Germany – the birthplace of the Passivhaus movement – for examples of trailblazing retrofits, in particular the brutalist 1960s building that houses the Faculty of Technical Sciences at Innsbruck University. “It’s a fantastic example of how we can maximise the value of existing buildings. They’ve repurposed and retrofitted it to the EnerPHit standard and brought an underperforming asset back to life.” The result, says Ian, is “exceptional environmental quality” that reduced the building’s energy use by 88%.

EnerPHit take-up in large campus buildings in the UK is still relatively novel, but the University of Cambridge has thrown its mortar board into the ring with the Entopia Building (the name, a slightly wince-inducing portmanteau of ‘environment’ and ‘utopia’, could probably do with retrofitting itself) set to become the most sustainable asset in the university’s estate.

Originally built as a telephone exchange in the 1930s, the £13million retrofit, to EnerPHit standards, is due for completion in early 2022 when it becomes the ultra-low carbon home of, appropriately enough, the University’s Institute for Sustainability Leadership.

Architect Ian Whittle, FaulknerBrowns


Speaking about the project back in March, Alexander Reeve, sustainable building advisor to Cambridge’s estates division said: “Through the project we have been able to demonstrate the viability of measures such as internal wall insulation and triple glazing which have significantly reduced the size of the air source heat pump installation and avoided the need to upgrade electrical substation capacity. This means the only significant external alterations are the glazing and a solar power photovoltaic array on the roof.”

As is the case with Greenwich’s inner-city rooftop meadows, almost any university estate stock century can be retrofitted for a green roof or outside living walls, says Benz Kotzen.  “Universities used to be synonymous with living walls – I mean, that’s why they called it the Ivy League in America, all those famous colleges clad with creepers. There is some reticence about retrofitting living walls – about attaching anything as cladding high up, post-Grenfell, and that’s very reasonable. But we’re currently doing a preliminary study looking at the historical risk of living walls and fire – there have actually been very few”.

If the roof is flat, and a load-bearing report has been carried out by a structural engineer – because even simple roof greening adds significant weight to a building – estates should knock themselves out, says Benz.

“It’s not a difficult exercise by any means – if the roof is already waterproof then you can get systems that literally just slot in place. The trick, and the cost, is maintenance”. Greening roofs and walls is an investment that takes its time to pay-out, he warns, “but when you think about the profit for the environment once they’re established you have to wonder why they aren’t a common sight.”


Main image: External view of the Sir Colin Campbell building and the GlaxoSmithKline Carbon Neutral Laboratory for Sustainable Chemistry, Jubilee Campus © University of Nottingham

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