Image courtesy of AFL Architects
An exciting and familiar home-from-home for legions of fans, football stadiums are culturally significant open-air spaces to experience the beautiful game.
But for decades, sports stadium development has prioritised scale over sustainability, locking in huge amounts of embodied carbon through reliance on concrete and steel in construction. Once operational, these entertainment titans consume massive amounts of energy, putting a strain on electricity grids, pressurising municipal water supply, even creating localised heat islands.
This, combined with the climate emergency is forcing a radical rethink of traditional stadium design. Two ambitious upcoming stadium projects in the UK are aiming to demonstrate how the thrill of live, mass-spectator events can be balanced with the urgent demands of a net-zero future. The expertise of chartered surveyors is crucial in achieving this, bringing the professional judgement that balances sustainability goals with deliverability.
Eddie Visscher MRICS is head of sports at RLB. He says that if sustainability is built in from the start, the long-term value of the stadium will usually outweigh the initial cost.
“Some measures add to capital cost, but they cut running costs, reduce exposure to energy prices and avoid expensive retrofits,” he says. “Investors and operators also increasingly price in ESG performance. Value should be measured through whole-life cost, operational savings, whole-life carbon, resilience, revenue and community benefit.”
With a target to become “the world’s lowest-carbon sports facility”, Forest Green Rovers' (FGR) new 5,000-capacity stadium in Stroud, Gloucestershire, will be crafted almost entirely from timber, a move intended to slash embodied carbon emissions.
The venue was designed by ZHA Architects, with planning consultancy Ridge and Partners, for club owner Dale Vince (who is also the owner of green energy provider Ecotricity) and recently gained detailed planning permission. It will form the centrepiece of the £100m Eco Park development, a 100-acre sports and green technology business park.
A holistic approach to green design will aim to minimise environmental impacts, both during construction, throughout operation and including eventual demolition.
According to the updated Design & Access Statement, the development is aiming to become carbon neutral or carbon negative and will generate more than 80% of its energy from on-site wind and solar, supplied by Ecotricity. Air source heat pumps with low carbon refrigerant are proposed for space heating, hot water and cooling demands.
A BREEAM ‘Excellent’ rating has been set as a minimum energy reduction target, with aspirations to become the first stadium to achieve BREEAM ‘Outstanding’. The project is also targeting UK-Green Building Council Net Zero verification in design, construction and operation.
Image courtesy of FGR
Choosing the right materials
Stadiums typically have a higher ratio of embodied carbon versus operational carbon, as compared to residential or commercial properties, and the vast majority of upfront carbon is contained in the building structure.
Efforts were therefore made by designers of the FGR stadium to reduce the weight of materials, which in turn reduces the need for over-sized structure, as well as to exploit alternative low embodied carbon materials, principally sustainably sourced glulam beams and cross-laminated timber (CLT). The main materials used to build the stadium will be wood, steel and concrete.
A transparent lightweight membrane for the roof will reduce permanent loads and column and beam sizes, also cutting the mass of concrete required for foundations. Options for concrete piles or pad foundations are being explored, with recycled content including ground granulated blast-furnace slag expected to further cut embodied carbon.
A louvred façade, made up of horizontal timber slats (a hardwood, possibly European larch or Douglas fir) will promote natural ventilation and function as a sunscreen and rainscreen.
Certain features are now a must-have for reducing emissions or hitting net-zero, says Visscher, such as “fabric-first design, all-electric systems with no fossil fuels, and on-site renewables such as solar PV. A structure designed to reduce embodied carbon from the outset and smart building controls that keep the venue running efficiently once open are now expected too”.
Going beyond the stadium, Visscher also highlights the need for a credible transport strategy, “because fan travel is often a stadium's largest emissions source”.
The building is designed for long-term adaptability to ensure its longevity and avoid demolition. The envelope, seating bowl and other facilities are designed to provide up to 10,000 seating capacity in future without adjustment to the superstructure or general arrangement of the stadium. Only a fit-out will be required with, for example, additional seating, concessions and toilets.
Another goal is biodiversity – the introduction of over 2km of new hedgerows, thousands of new trees, wetlands and the restoration of a canal, is expected to result in a 12% improvement to natural biodiversity on site.
“Value should be measured through whole-life cost, operational savings, whole-life carbon, resilience, revenue and community benefit” Eddie Visscher MRICS, RLB
Image courtesy of AFL Architects
Electrifying performance
Also looking to score high on sustainability, Oxford United Football Club’s £150m new stadium is being billed as the UK’s “first all-electric football stadium” and the country’s “most sustainable mid-sized sports venue”.
Detailed plans for the 16,000-seater ground, located in Cherwell, north of the city centre near Oxford Parkway train station, were developed by AFL Architects and Ridge and Partners, gaining planning approval earlier this year.
The project will replace the existing Kassam Stadium, located to the south of the city, and includes a 180-bed hotel, gym, restaurant and conference and event facilities. The stadium will operate entirely on renewable energy, thanks to 3,500m2 of roof-mounted photovoltaic panels, covering an area equivalent to roughly half the size of the pitch.
Air-source heat pumps and energy efficient building fabric will further limit the need for fossil fuels and provide an 80% reduction in CO2 emissions per year, compared with gas boilers.
A design optimisation process, by engineering services designer Mott MacDonald, led to the adoption of low energy lighting with automated occupancy and daylight controls, and occupancy-led heating, ventilation and cooling control strategies.
Electrification is key to national decarbonisation plans, but electricity prices remain significantly higher than gas. This ‘spark gap’ required the engineer to carry out advanced modelling to reduce peak energy demand, whilst also demonstrating regulatory compliance.
Combined measures for renewables and energy efficiency are expected to cut overall carbon emissions per square metre by around 25% compared to other recent mid-to-large-scale stadia projects in the UK. Mott MacDonald also developed the structural design, which will exploit a lean optimised structural frame and a timber roof to limit embodied carbon.
A Life Cycle Assessment carried out at RIBA Stage 2 to support the BREEAM assessment (project is targeting a BREEAM ‘very good’ rating) will be fleshed out in more detail as the project moves towards construction.
The goal for any sustainable venue built from new is to minimise whole-life impact while maximising long-term value, says Visscher. “Sustainability is also no longer just environmental: social value increasingly sits at the heart of corporate sustainability, and stadiums are well placed to deliver it through local jobs, skills, regeneration and community use. The most sustainable venues are often those used most, well beyond just matchdays.”
Project designers for Oxford’s stadium also considered how to cut emissions related to supporters getting to and from the stadium. Improved public transport and active travel links will mean that up to 90% of journeys to and from the stadium are made this way.
“The most sustainable venues are often those used most, well beyond just matchdays” Eddie Visscher MRICS, RLB
In the big leagues
Forest Green Rovers and Oxford United are building 5,000 and 16,000 capacity stadiums, but could some elements of their design be scaled up to build the kind of 100,000 capacity stadium Manchester United is aiming for? Visscher thinks so.
“The principles can absolutely scale, even if the solutions need to evolve,” he says. “An all-electric stadium, renewable energy, lower-carbon materials and strong public transport connections remain just as relevant at 100,000 seats as they are at 20,000 seats.
“The challenge is that the practicalities become more complex. A stadium of this scale will still require significant amounts of steel and concrete, with timber used where practical and technically appropriate. Likewise, while smaller venues can generate a large proportion of their energy needs on-site, the energy demand of a 100,000-seat stadium grows far more quickly than the available roof space available for solar panels.”
As Visscher highlights, every stadium, whatever size, can be designed and built with sustainability in mind. However, he adds, one question that chartered surveyors should consider is “whether a new build is necessary at all, or whether there are options to refurbish or expand an existing stadium”.
