Making Natural Building Materials Work

With the buildings and construction sector accounting for over 34% of global energy demand and around 37% of energy and process-related CO2 emissions in 2021, decarbonising the buildings sector by 2050 is critical to delivering our climate objectives yet with 70% of the building stock in Africa by 2040 alone yet to be built, how can we achieve a sustainable built environment? The intelligent and creative use of natural building materials provides a critically important solution to so many of the challenges we face, and, in this event, we considered some of the many benefits they provide together with  obstacles to be overcome. The following short video from Builders for Climate Action in Canada, illustrates the issues.

• Ms Isabella Stevens, Policy Officer, Climate & Sustainability, Royal Academy of Engineering, UK
• Prof Neil Thomas MBE, Director and founder, Atelier One. UK
• Prof Rowland Keeble, Director, Rammed Earth Consulting. UK
• Mr Alan Chandler, Dean of Research, University of East London. UK
• Mr Christian Benimana, Principal & Managing Director, Mass Design Group. Rwanda

1. Scene setting: Isabella Stevens provided framing for the event by positioning the subject matter in the wider global context, including the need for demand reduction, the social and environmental effects of mining, the urgent need to decarbonise construction and respect planetary boundaries.
2. Bamboo: Neil Thomas described the properties of bamboo in both its natural, and engineered forms together with a range of case studies highlighting the diverse ways in which it can be used.
3. Earth Construction: Rowland Keeble described the variety of ways in which earth can be used as a construction material, together with a variety of standards and codes of practice that have been developed to support its use.
4. ‘Sugarcrete’: Alan Chandler described the background to the development of sugarcrete together with its properties and the efforts to encourage its adoption
5. Case Studies: Christian Benimana presented a series of short case studies to illustrate the way in which the Mass Design Group has used natural building materials in its work, together with lessons learnt.
6. Panel Discussion and Q&A: Following a series of short framing presentations, the panel responded to a series of questions from the moderator and participants.

The following are among a list of lessons learnt during the course of the event:

• We must quickly reduce our reliance on concrete and steel if we are to meet our climate objectives, while making the most of the existing building stock through adaptation and re-use.
• We need to better understand the social and environmental impact of mining and mineral extraction and accelerate the transition from a linear to a circular economy
• The appropriate use of natural building materials when combined with effective planning and passive design principles can not only reduce embodied carbon but can also reduce operational energy use
• We need to accelerate the adoption of natural building materials through advocacy, training and skills development.
• The successful use of natural building materials relies upon a better understanding of building physics and requires a more integrated approach among members of the design team.
• Regulatory systems need to be updated to recognise and encourage the use of such materials, and standards calibrated appropriately; noting that opportunities for the responsible use of such materials also exist in countries where the regulatory system may currently be weak.
• The adoption of natural building materials provides an opportunity to rethink and recalibrate standards around what is necessary and not simply what has become customary.
• Academia is failing to teach students the importance of natural building materials and how to use them in practice.
• Built environment professionals need to be educated to better understand the impact of their work in the context of climate change and planetary boundaries.
• Public sector and clients should be encouraged to show leadership by leveraging public procurement to promote circularity and the adoption of natural building materials, capitalising on the opportunity for public buildings to showcase the way in which such materials can be used.
• It is important to both understand and demonstrate the social and economic benefits to be achieved through the use of natural building materials, including the benefits for health and well-being.
• Networks, such as EBUKI, can be very successful in advocating for the use of natural building materials, breaking down barriers between architects, engineers, constructors and other stakeholders
• Architects should be encouraged to consider the impacts on the entire supply/value chain which arise from using natural building materials.