AJ Climate Champions

Vinu Daniel, who transforms mud and waste into architecture, discusses his approach of using materials from within five miles of a site. He emphasizes the need for architects to be on site, not in the office, and advocates for earth construction to become mainstream, even if it means adding small amounts of cement for structural strength.

Episode 50. AJ Climate Champions with Hattie Hartman and Joe Jack Williams.  Carmody Groarke sustainability lead Sian Ricketts explains how architecture can adapt to the reality of finite resources and an abundance of waste. Ricketts says that architects should develop their intuition and new rules of thumb to design for a changing climate. Architecture needs to adapt to incorporate materials from waste streams, and this requires a new approach to detailing and ongoing maintenance. ‘The industry is going through a huge learning process and we should not be scared of getting it wrong,’ she says. Marginal gains on every project are important. In this episode, Ricketts describes the process of developing a bespoke brick for the Design Museum Gent in Belgium. She explains that the practice did not start with a bespoke brick in mind. Because conventional clay-fired bricks are high in embodied carbon, an exploration of less carbon intensive alternatives led to an in depth collaboration with Local Works Studio and Brussels-based bcmaterials that in turn led to incorporating local waste streams into the design of the new brick. Ricketts observes that the process of developing the bespoke brick for Ghent has strengthened the practice’s confidence in seeking opportunities for both innovation and circularity in future projects. Carmody Groarke is currently working with Imperial College-based startup Seratech to explore the use of magnesium carbonate as a binder for bricks. For show notes and to catch up on all AJ Climate Champions episodes, click here.

Ep 49. Structural engineer David Watson describes the enduring appeal of brick and its underexploited superpower: reuse Brick has many advantages: durability, aesthetics, use as both envelope and structure, and the possibility of local (even artisanal) production. This last point differentiates it from steel and concrete, due to the Ordinary Portland Cement needed for concrete production. ‘We need to ‘build our intuition about what impacts embodied carbon and emissions from different materials,’ says Watson. Watson highlights the importance of querying the firing required to achieve different finishes, because it varies between brick types and can significantly impact overall embodied carbon. It’s also important to understand the fuel used in the kilns where bricks are fired.  While in the UK this is predominantly natural gas, abroad it might be charcoal or coal, both of which generate significant amounts of particulates. In non-loadbearing cladding applications, the embodied carbon of the support systems must be taken into account because they can comprise as much embodied carbon as the brick and mortar combined. These hidden impacts are often difficult to calculate due to lack of EPD data, explains Watson. Brick reuse is on the increase but currently comprises less than five per cent of the market because of the challenge of removing the mortar, particularly those bound with Ordinary Portland Cement. Traditional lime-bound mortars are easier to remove. Current research is exploring mechanised removal of cement-bound mortars, and increased demand should prompt the market to respond, says Watson. In this episode, we also discuss ConcreteZero targets (AKTII is a signatory) and the extent to which they rely on GGBS. Watson stresses the necessity of ‘using less’, for example, exploring ribbed, coffered or troughed slabs as an alternative to flat slabs. He advocates form-effective design, marrying structure with architectural expression in a lean use of materials. David Watson can be contacted at david.watson@akt-uk.com. To catch up on all episodes of AJ Climate Champions, click here.

Episode 48. AJ Climate Champions with Hattie Hartman and Joe Jack Williams. Structural engineer Eva MacNamara of Expedition Engineering explains how we can radically reduce our use of concrete and how to better understand the biodiversity impacts of material choices. In this episode, we dive into the tricky topic of concrete and unpick the widespread mantra that ‘concrete is bad’.  Concrete is ‘an addiction’ that has led to an obese construction industry, says Expedition’s MacNamara; it is not going to go away but we can radically reduce our use of it. She describes a porposed slab design for the Eden Project site in Dundee which would achieve an 80% reduction in concrete volume. MacNamara stresses that ‘using less’ is much more impactful than substituting low-carbon concretes and notes that she repeatedly sees practitioners over-specifying. We discuss some of the nuances of concrete use: which applications are most appropriate, how to reduce the volumes we use, and why low-carbon concrete – especially GGBS – is not a silver bullet. We also touch on upcoming innovations including Seratech, ‘funnel’ slabs and smart crushing. McNamara explains how to bring both carbon and biodiversity into the concrete procurement process. Highlighting findings from the recent report The Embodied Biodiversity Impacts of Construction Materials (Expedition/ICE, November 2023), she notes that 95% of biodiversity impacts occur off site and that the new biodiversity net gain requirements only address the 5% on site, so designers must look beyond a site’s boundary. Finally, MacNamara advocates finding a place to innovate on every project. ‘We can make the most difference by using our projects as springboards for incubating innovation,’ she says. For show notes and to catch up on all AJ Climate Champions episodes, click here.

For the first in a new six-part series on materials, Hattie is joined by co-host Joe Jack Williams to interview Martha Lewis, head of materials at Danish practice Henning Larsen. Lewis argues that a baseline of health and environmental impacts should inform material specification, and explains why a holistic approach is essential to navigate the nuances of material selection. She describes how the European focus on life cycle analysis and the Global Warming Potential of materials is starting to be integrated with the earlier American focus on healthy materials and toxic chemical content. ‘The glut of information is a challenge of our time. How do we navigate too much information to make the right decisions?’ asks Lewis. She advocates for material passports which would consolidate the relevant data needed to make informed decisions: carbon emissions, chemical content and circularity. She also argues that certification schemes, despite their weaknesses, are the most effective route to ensuring that a project delivers on its sustainability aspirations. Also in this episode, Lewis describes Unboxing Carbon, a database with an accompanying course which she has developed to upskill architects on the carbon aspects of material selection. Lewis has rolled out Unboxing Carbon across Henning Larsen’s 700-strong practice and also offers it to external practices. For show notes and to catch up on all AJ Climate Champions episodes, click here.

Andrew Waugh, founding director of Waugh Thistleton, discusses the benefits of building with timber to address industry transformation at scale. He explains why tall buildings are not sustainable, how timber housing can reduce carbon burden by 75%, and the need to stop building basements. Waugh advocates for using UK-grown timber for construction and clarifies end-of-life alternatives. He also shares insights on the sustainability of timber sourcing and the importance of subsidies to support timber construction.

Episode 45. AJ Climate Champions with Hattie Hartman and George Morgan. Two Public Practice associates explain how working in the public sector has increased their agency as designers. Public Practice is a social enterprise that places built environment professions in the public sector, primarily in place-making roles and increasingly in key roles that drive retrofit and net zero. ACAN co-founder Lauren Shevills, now lead retrofit innovation and delivery officer at Westminster City Council, explains that Public Practice has changed the trajectory of her career, enabling her to marry her passion for community and stakeholder engagement with technical architectural expertise. Steve Westcott, low carbon programme manager at Greater Manchester Combined Authority, says Public Practice has empowered him to work more strategically and ‘be closer to the conversations’ that matter. Off the back of Westcott’s role, GMCA is recruiting additional Public Practice associates. On the subject of retrofit, Shevills observes that one major challenge is that retrofit cannot be mandated because it’s currently not part of the planning process.  A retrofit first policy requires a rethink of current guidance and Westminster Council has five workstreams underway to explore various aspects of retrofit. Westcott explains that a fabric first approach is often too costly. The GMCA is developing portfolio-wide data collection for the city’s non-domestic estate to inform future grant disbursement decisions. For show notes and to catch up on all AJ Climate Champions episodes, click here.

Je Ahn, founding director of Studio Weave, talks about the challenges of sourcing timber from London's streets and parks, including the need to prove its chain of custody without FSC certification. The use of found materials allows for improvisation and new aesthetic opportunities, as seen in the Lea Bridge Library Pavilion. Ahn emphasizes the importance of project-specific sustainability and achieving the right balance of materials. They also discuss the role of an architect in effecting change and their personal journey in the field.

Ep 43. AJ Climate Champions with Hattie Hartman and George Morgan. London Eye architect Julia Barfield explains how the climate emergency changed the way her practice, Marks Barfield, operates, as well as what’s ahead for the Architects Declare movement. Julia shares insights from recent projects on how to achieve circularity in retrofit, the challenges of stockpiling materials for reuse  and how Orms’ material passports can be adapted for retrofit. ‘We must treat all materials as the precious resource they are,’ she says. She talks about her practice’s Stirling Prize-shortlisted Cambridge Mosque, which is part of a Built by Nature-funded post-occupancy study evaluating the quality of life and performance aspects of five CLT buildings. We also speak to Julia and fellow Architects Declare steering group member Zoe Watson about what AD has achieved four years on as well as its current workstreams, including climate emergency training for design review panels and Meet the Steering Group sessions where AD signatories can seek practical advice on how to further sustainable design within their own practices. As part of an ambitious strategy for change, AD is launching a three-part roadmap aimed at equipping Government policymakers with practical and impactful policies to reduce emissions, kickstart the circular economy and restore social and natural infrastructure.  AD plans to launch its document in Parliament in 2024. For show notes and to catch up on all AJ Climate Champions episodes, click here

Episode 42. AJ Climate Champions with Hattie Hartman and George Morgan. Montreal-based architect and systems thinker Scott Francisco explains why architects must educate themselves to understand the nuances of timber sourcing. Francisco believes that greater use of timber in construction in coming decades will be essential to meet our climate targets. This in turn means an increase in plantation forestry, but this can be achieved without compromising biodiversity.  He also explains why it’s crucial for designers to have a holistic understanding of the timber supply chain. While timber certification is important, relying on certification alone is not enough. He outlines the range of factors that impact the carbon footprint of timber and how to understand different sourcing strategies. Architects can play an important role in specifying ecological timber by asking the right questions and educating themselves to understand that specifying a species and a grade is not enough. In some instances, particularly on smaller projects, architects can construct a timber value chain for a particular building. For show notes and to catch up on all AJ Climate Champions episodes, click here.