After a successful symposium on Friday 21st June, here’s a summary of the work presented…
The day started with an inspiring introduction from our Commander-in-Chief, Dr Francesco Pomponi, covering the ethos and research areas of REBEL. REBEL’s vision is to accelerate the transition to a world that lives within the planetary boundaries and develops sustainably. The research areas enable this vision to become a reality; material efficiency, LCA and embodied carbon, the circular economy and sustainable development. Francesco also talked about an important piece of research he recently published with Dr Bernardino D’Amico.
Francesco’s expertise in the measurement, management and mitigation of the impacts of the built environment and Bernardino’s analytical skills and his prowess with mathematical and numerical modelling gave rise to a newly developed metric. They developed a compactness measure of sustainable building forms which quantifies the relationship between envelope surface area and indoor space. This allowed an optimal built form to be defined based on energy consumption and environmental impacts. This work has resulted in a highly useful tool that can be used by architects, engineers and designers to measure the compactness of building forms as a function of their shape. This tool can then be used to steer design towards alternative forms that are closer to the optimal.
Denser and taller
This introduction was followed by a presentation on the work of a short-term research project, led by Francesco and Bernardino and conducted by Ruth Saint and Niaz Gharavi. The project is titled “Denser and taller urban environments: is it the right path to building sustainably?” and was introduced in a previous blog. Urban areas hold 54% of the world’s population which is expected to increase to 66% by 2050 and these people need to go somewhere. There is a growing belief that building taller and denser is the way forward as it optimises the use of the space and can house more people per square meter – so limit urban sprawl and just build up! However, is this beneficial from an environmental impact point of view?
This research focuses on the carbon aspect of “environmental impacts” and assesses the whole life carbon (WLC) associated with different built forms and different urban scenarios. WLC covers both the operational carbon, i.e. the carbon generated while the building is in service, and the embodied carbon which is arguably more important. The embodied carbon is all the hidden, behind-the-scenes carbon that is produced during the extraction and production or raw materials, the manufacture of the building components, the construction of the building itself, the deconstruction at the end of the buildings useful life and the transportation required between each phase. This embodied aspect is often overlooked, especially in building design, with operational efficiency always at the forefront. The argument for cutting carbon in the design stage has been made by numerous researchers, and vehemently by Francesco, but it’s still something that’s largely ignored! So, we must keep driving this point home! Sustainability starts from scratch!
To determine whether a denser and taller urban environment is more sustainable in terms of WLC, different urban scenarios had to be developed. Based on primary data taken from case studies across the UK and EU, Niaz developed a parametric model that randomly generated different urban environments depending on certain input parameters. From published research, Ruth found the embodied carbon coefficients (of the envelope and structure) and operational carbon for different built forms which were applied to the output of the model. This gave a total WLC for each urban scenario.
Stay tuned to find out the results…
“Our struggle for global sustainability will be won or lost in cities”UN Secretary General Ban Ki-moon
Embodied carbon in construction
Following on from the impact of different urban topographies, Jim Hart focused in on the different materials that can be used in a building’s structure. This research project, led by Francesco and Bernardino and funded by an EPSRC grant, compares a host of structural frame designs, composed of different materials, in terms of WLC. Buildings and the construction industry are a major source of greenhouse gas emissions and top contributors to climate change, particularly building structures. Jim talked through the process of data collection, gathering the masses and WLC emissions associated with steel, reinforced concrete and engineered timber building frames. These different frames were compared for 127 different structural frame configurations. Jim and the team found a clear distinction between the masses of the three configurations, with the concrete frame being the heaviest and timber the lightest. For WLC, the typologies are more closely grouped with large overlaps between the resultant distribution of embodied carbon coefficients (ECC). However, engineered timber is the most likely to produce a frame with a low associated WLC. Jim’s work highlighted the importance of considering ECC as a range, not a point value, so as to account for the vast uncertainty that is prevalent in emissions databases.
Post-disaster and post-conflict (PDPC) sheltering
Finally, the pièce de résistance! “Circular Design Of Emergency Sheltering For Africa: A Holistic Approach” is a multi-disciplinary project with a multi-disciplinary team, supported by the Royal Academy of Engineering. The presenters were Dr Lara Alshawawreh talking on “Post-disaster and post-conflict sheltering: Novel designs and existing solutions”. Dr Francesco Pomponi’s presentation was titled “Sustainability of post-disaster and post-conflict sheltering in Africa: what matters?”. Finally, Sue Snaddon discussed “Sustainable sheltering for the displaced: where do we go from here?”.
Lara opened the session with some statistics on the number of forcibly displaced people (70.8 million, of which 25.9 million are refugees) worldwide. Africa is the continent with the highest number of displaced people due to wars, humanitarian crises, resource scarcity, and extreme climate events. Africa hosts approximately a third of the world’s refugees; 6.3 million. Emergency sheltering is an important step toward recovery; for displacement outside a home country shelters are unavoidable, the situation in PDPC areas could take years to resolve, and the vulnerable people who are affected cannot afford other options. Emergency sheltering always sets out with the best intention of being a temporary solution but, in most cases, it actually turns into a (semi-)permanent habitat. Shelter should be an incremental process, allowing users to upgrade their shelter over time; design with the people not for them.
For this study, the team categorised shelters into novel designs and existing solutions and then reviewed these against the three pillars of sustainability; environmental, economic, social. Francesco followed Lara’s insights with some results from a mixed methods approach. Delphi and Analytical Hierarchy Process (AHP) methods were used. The AHP was used to assign weights to the sustainability criteria. Two rounds of Delphi were used to first reach consensus on a manageable number of agreed shelter design solutions. The second round was to reach consensus on the scoring of identified solutions based on the sustainability criteria. For the Delphi method, a diverse panel of experts were chosen in terms of professional background, geographic location and gender. The clustered results of the AHP showed the most important sustainability aspect to be social, followed by environmental. The Delphi method produced several solutions that might work best depending on the context.
Finally, Sue wrapped up with the important question: where do we go from here? The project aimed to address design issues from a circular economy perspective and engineer hybrid solutions that can be instantly deployed but easily adapted or expanded by the residents as a way to achieve their social needs and their long-term empowerment. The proposed solutions were assessed in terms of their environmental impacts through life cycle assessment and their social components were evaluated with the support of local partners. Sue talked through the final proposed design and alluded to a future prototype that could be applied and tested in the field. The work done by this team covers very sensitive, real-life issues and proposes life-changing solutions.
“In Syria we are killed by bombs, but in Zaatari we die from the cold. The bathrooms and kitchens are crowded and unclean, and there is no privacy or dignity.”A Syrian refugee.