What sustainable construction looks like at Unite Students
7 November 2023
Unite Students has committed to becoming a net-zero carbon organisation by 2030 – with new developments in particular being targeted for a reduction in carbon.
But what does a sustainable new development look like in practice right now, what solutions are there to key sources of embodied carbon, and what are some of the challenges being faced when it comes to building sustainable new developments?
Building on our recent ‘The future of sustainability in student accommodation’ episode of Accommodation Matters, we’re now sharing our full interview with Nicholas Pigula, Sustainability Construction Manager at Unite Students.
Hosted by Jenny Shaw, HE External Engagement Director at Unite Students, tune in now to find out:
- What we’re currently focusing on to create more sustainable buildings
- How we’re targeting reductions in embodied carbon
- His favourite examples of net-zero developments
- What sustainable features have been built into our newest property, Nottingham’s Morriss House
- What we’re focusing on next in our drive for net-zero
Our Sustainable Construction Framework is coming soon – sign up here to be updated when it’s live.
Download the episode below:
‘What does sustainable construction of student accommodation look like?’ episode transcript
Jenny Shaw: Hi, Nick. What does it mean to be a Sustainability Construction Manager?
Nicholas Pigula: I work in the development team for Unite Students. We build all of our new PBSA [purpose-built student accommodation] and also now our build-to-rent products. Within the team I in effect look after, or develop, our approach to sustainability on our buildings. That means looking at a range of different environmental and social impacts associated with our construction projects.
Jenny: Before we dive into that, and what that means, what’s your background? How did you get into this kind of work?
Nicholas: I’ve worked in sustainability now for about 13 years in various sectors. I originally started in local authority working as a climate change project officer. Then from that I moved into architecture as a sustainability consultant. Then joined Unite Students to go client-side about a year and a half ago.
Jenny: Can you break it down for me, sustainable construction? What does it mean? What kind of impact are you looking for at the end of the day? What’s achievable?
Nicholas: Probably the best way really to describe what sustainable construction is, is we often talk about sustainability as having three pillars, so environmental, social, and economic sustainability. Traditionally everyone is, I think, aware of carbon emissions, and that’s still probably the big driver in the built environment in regards to sustainability. That’s about driving down the carbon emissions associated with the energy consumption within our buildings.
Also, now there’s a big emphasis on the carbon associated with the materials and the construction process itself, which we refer to as embodied carbon. As well as carbon, there’s a big focus on biodiversity, so the ecological impact as well as the impact on climate change, but also benefits to people and the occupants of buildings as well and their connection with nature.
I guess building on from that, the social part of sustainability is really about how our buildings provide a good environment for those occupants within it, so providing good air quality, a sense of well-being. Things like acoustics and lighting can all have an impact physically and mentally as well as that consideration about the impacts of the buildings themselves and directly onto the people.
We think about sustainability across the life cycle of the building. That really starts from the mining of the raw materials and the impact on the environment and the people involved with that process through to the construction of the building. Then, increasingly, the end-of-life impacts of the building – so what happens to that building and how do we preserve the resources and reduce the impact of the demolition?
Jenny: It’s a huge, holistic piece really, isn’t it, that you’re looking at right from the start, right through the supply chain, and right through to the end of the building’s life. In terms of the actual development of buildings because I know there’s been a lot of focus on this, what is possible at the moment in terms of reducing that embodied carbon? What are some of the innovations that are going to take us further down that road?
Nicholas: This is an area where I think certainly in terms of PBSA, Purpose built student accommodation, the first thing to do when thinking about embodied carbon and reducing the impacts is make sure you can measure it properly, and that’s actually a real challenge. We’ve spent probably the last year or so really refining that process as to the tools that we use, and the methodologies that we use, and the data that we collect in order to make sure that we fully understand the embodied carbon impact of our buildings.
What we found during that process is that it’s useful to look at where the greatest embodied carbon is within the building. Generally speaking, around 60% of the embodied carbon is located within the structure of the building. That’s the foundations, and the frame, the columns, and the floors, et cetera. That’s generally within our buildings is generally concrete and steel. Not only are they found in large quantities within the building, they’re also quite carbon intensive. For every kilogram of material, you have a kilogram of carbon emitted within the manufacturer and assembly of that product. For those materials, that’s quite high.
What we’ve done is in the first instance, we’ve targeted that, and so we now use cement replacement. Concrete is basically made up of cement, sand, water, and aggregate. It’s a cement element that’s highly carbon intensive. We’ve been replacing the cement content, well, up to about 40% of it at the moment with something called GGBS, which is ground granulated blast slag, a byproduct of the steel industry. In effect, we’re taking a waste product and we’re using that to massively reduce the carbon impact of our buildings.
Also, something that we’ve been doing, and actually, it’s probably a happy coincidence, we actually selected a façade product in the last few years, based on the program and cost savings that are associated with that product. It still gave us a high quality façade that we wanted, but it could be installed at a faster rate than the traditional brick façade.
Actually, we found out that that’s got huge carbon savings. Part of my role is to look at the net zero carbon constructions out there on the market and the feasibility of those constructions. Actually, by chance, we’d really come across one of the lowest carbon options available to us.
Jenny: Are there any good examples of net zero carbon construction buildings?
Nicholas: There are. I would say student accommodation is possibly slightly further behind than some other sectors. There are some good examples of student accommodation that’s been developed recently. I know in Leeds, Newcastle, and Bristol, there’s been some ‘Passive House’ student accommodation that’s been developed. Passive House, for those who don’t know is a very low energy approach to design and construction. Associated with that, you have low operational carbon emissions.
Actually, we haven’t achieved a Passive House development yet partly because our developments are quite large, and it’s a lot more feasible at the moment to do that on smaller scale developments. We have been adopting the principles, and we’re quite close to Passive House levels of performance. Our recent development and our current pipeline of developments are industry leading in terms of their operational energy performance.
One of I think the challenges that we’ve found is achieving very low embodied carbon within our developments. Part of that is down to things like building regulations and insurance. It’s quite difficult to use timber, which is a very low carbon construction material. We see lots of commercial offices and actually university buildings where they’ve incorporated timber. A really good example is the Enterprise Centre in the University of East Anglia, if anyone’s interested. That’s probably the most sustainable building I can think of.
Jenny: What are the barriers to doing something like that in accommodation?
Nicholas: The challenge really is around building regulations in terms of the use of timber on facades. Once you exceed a certain height, you’re unable to use timber as it’s potentially combustible. Insurance is a big issue. That’s quite a big blocker.
Potentially there’s opportunities to use, I mentioned it, CLT, which is cross-laminated timber, which is a very efficient form of timber construction, which is incredibly low carbon, but there are issues. Insurance companies can be quite reluctant or historically have been very reluctant to insure buildings constructed of that. People think it’s because of fire, but actually I believe it’s down to leakage.
Jenny: You mentioned ecological impacts. Are there any good examples, either in Unite’s buildings or elsewhere, of a really positive approach to biodiversity within PBSA?
Nicholas: Our latest development at Morriss House in Nottingham, which has just opened this year, is probably a great example, actually, of how we’ve basically taken a brownfield site and completely redeveloped it into, I think it’s 706-bedroom accommodation just next to the Jubilee Campus.
We’ve created some really good green space, not only for students to use, but also there’s some great planting selections that maximise biodiversity opportunities. Also, it’s created this green corridor connecting the Jubilee Campus with student accommodation, so the students can walk through a nice landscaped green space on the way to their lectures in the morning and back.
Jenny: That’s lovely. Paint me a picture – what does it look like? Is it like a beautiful meadow or something like that?
Nicholas: It’s looking very nice at the moment, but I’m sure as the planting matures, it will look even nicer in a few years’ time.
Jenny: What flora have you got in there? Is it native species, wildflowers, or is it more a garden landscape sort of thing?
Nicholas: It’s a bit of a mixture. We’ve incorporated some green roofs, and then we’ve got some landscapes, gardens, and then the native shrubbery.
Jenny: Just to finish us off, what does the future hold? You said it’s still quite difficult to get to net zero in terms of the development, the embodied carbon, but how is that going to change in the future? What’s coming over the horizon that’ll help us do that?
Nicholas: I think we are transitioning quite well to net zero carbon. We’re following the RIBA 2030 Climate Challenge. In effect, we want to be net zero by 2030, which means hitting the embodied carbon and operational targets. We’re actually on track with our embodied carbon at the moment. We’re actually pushing an aggregated target of around 27/28 at the moment for our projects. We are slightly ahead of schedule.
However, there is a big step change required to push beyond that. There’s going to be a real drive to look at bio-based products where we can push for the use of things like CLT, but actually primarily the first instance.
Again, this is visible with one of our developments, Bromley Place in Nottingham, where we’re using adaptive reuse of an existing building. We’re able to basically make huge carbon saves through the reuse of existing buildings and prioritising refurbishment over demolition, which carries challenges, but actually can also carry some big rewards in terms of carbon savings. I think something the industry is really driving now is this principle of the circular economy and resource preservation.
As we do decarbonise the grid, as we improve the efficiency of our buildings, they will inherently become much lower carbon. I think the switch probably in the next few years will be slightly from carbon to I think resource preservation.