Helping deliver the UK’s lowest carbon new build workspace
It’s an exciting time for construction, with innovations that are making the creation of truly sustainable buildings a reality. In Manchester, members of our team are providing fire engineering advice on what is set to be the UK’s lowest carbon new build workspace, Ev0. Our associate director Jamie Gibson explains how we are providing fire engineering support on this pioneering exposed timber development…
Since September 2020, project director, Danny Hopkin and I have been involved in the £30m Bruntwood’s Ev0 building, at the Didsbury Technology Park. As a milestone project in terms of sustainability, this six storey commercial development has been designed and developed as a commercially viable net zero carbon building – a huge achievement which will pave the way for other, much-needed sustainable office projects in the future.
Upon completion, its impressive credentials will include meeting the LETI 2020 design targets for ‘upfront carbon’, RIBA’s 2025 targets for whole life carbon and the UK Green Building Council’s Paris Proof operational energy use targets, as well as aiming to achieve the BREEAM Excellent certification and NABERS 5.5 stars for its operational carbon emissions.
Much of these credentials will be a result of its use of timber which is forming an important part of the complex design – the building will store approximately 4000 tons CO2e of CO2, and low-carbon concrete, which minimises upfront embodied carbon emissions to circa 500 kg CO2e/m2.
Our brief was to develop a fire strategy to support design aspirations for a low carbon six storey office building, to be constructed using as much exposed structural timber as possible. As timber is used extensively throughout the building structure, our team has been involved to provide specialist guidance in this area, one in which we have developed substantial expertise through our previous project and research activities. We are in the advantageous position that several of our colleagues have direct research experience of working with mass timber exposed to fire and have studied the topic in the process of completing PhDs. As a business, we not only employ bright minds but we have also made an ongoing commitment to furthering knowledge in the space of mass timber and fire, with two PhD students currently being funded at the University of Edinburgh and University of Sheffield, respectively.
On Ev0, we had to thoroughly consider the method of demonstrating compliance with the Building Regulations. Typically, this would involve the use of regulatory guidance commonly used for office buildings e.g. the Approved Documents and BS 9999. However, a key consideration for this building is that standard guidance gives limited consideration to the building structure having the prospect of contributing as a source of fuel. Therefore, it was important for OFR to establish where it is reasonable to use such guidance and where alternative methods were required to support compliance with the Building Regulations. To ensure the Ev0 structure performs adequate in the event of fire, we have utilised the guidance that our team drafted for the Structural Timber Association (STA), to demonstrate that there are various routes for engineers to demonstrate compliance. The route and fire engineering complexity is largely driven by the use and height of the building, together with the extent and exposure of mass timber elements.
To develop a holistic fire strategy that considers all relevant fire hazards associated with the timber construction, we have adopted a defence-in-depth performance-based approach for Ev0, which draws upon knowledge and experience across a variety of sectors, including our work within the industrial process industry. This collaborative approach on this project considers seven key safety layers of fire safety in buildings, developed by the Modern Building Alliance and known as the EU Fire Safety Guide. This method requires detailed consideration of the role of several safety layers that mitigate an initial ignition from developing into an uncontrolled fire, i.e. prevention, detection, early suppression, evacuation, compartmentation, structural safety and firefighting. In developing the strategy, a systematic and detail focused review was carried out to ensure sufficient lines of defence and layers of protection are afforded to occupants using the building, and firefighters who may need to enter the building.
Using our collective experience and academic expertise in this area, the Ev0 building has also presented our team with an opportunity to apply the knowledge and tools developed in the process of supporting leading CLT suppliers Stora Enso, Binderholz and KLH in the delivery of their Structural Timber Association (STA) research project on CLT enclosure fire behaviour.
We were appointed by the developer, Bruntwood and have worked closely with other design team members, including Ramboll, who is providing sustainability, MEP, and structural design expertise to Bruntwood and Sheppard Robson architects and Deloitte Real Estate planning consultants. Remaining an important part of the wider project team, our involvement on Ev0 is ongoing and we are appointed through RIBA Stage 4 (Technical Design) and RIBA Stage 5 (Construction) to ensure the fire strategy is implemented as intended and that the final building performs as expected.