Delivering assets in a deeper shade of green across Africa
In the next few decades, rapid urbanisation and population growth will mean a significant rise in construction activity. It is anticipated that the continent will account for close on 35 percent of new floor area between 2040 and 2060. With this in mind, and against the backdrop of the global climate crisis, it is critical to implement ‘greener’ building practices to benefit both communities and the environment in the long term.
It is a regrettable reality that the building and construction industry has been a significant contributor to the current crisis. According to the World Green Building Council, buildings are responsible for 39 percent of energy-related carbon emissions globally.
Acutely aware of the industry’s role in climate change and the urgent need for action, progressive developers and other stakeholders in Africa are advocating for more responsible, sustainable practices and greater adherence to green building codes.
Making a material impact
There’s a narrow window of opportunity for developers to start at zero rather than race to zero. And this is where the choice of building materials plays a key role in green building and sustainability.
The reality of population growth and urbanisation across Africa means there simply aren’t enough buildings to go around. Over the next 40 years, the vast majority of construction will be on the continent.
If we continue building as we have been, urban areas will mostly comprise structures made out of concrete and steel – the materials that make the largest contribution to the industry’s impact on the environment. Embodied carbon (the carbon associated with materials and resources used in building) is also becoming a growing concern.
There are several strategies to mitigate this, including reducing the amount of material used through design prefabrication and more efficient structures. But the biggest impact will come from replacing and fundamentally changing the materials used to build.
Benefits of bio-based materials
Bio-based materials, particularly wood, offer a viable alternative. Because trees absorb and store carbon from the atmosphere, the carbon remains within the wood and is not released unless the wood is burnt or decays. Using wood in buildings is a way to store carbon so it is not a threat to the atmosphere for decades, if not centuries – and avoid using concrete and steel.
About one cubic metre of wood stores roughly one tonne of carbon. If 90 percent of all new buildings were made from wood, we would essentially cut global emissions by around 4 percent - which is more than the carbon footprint of flying.
The last two or three decades have seen the emergence of cross-laminated timber (CLT) as an alternative building material across the world and in various markets. CLT essentially involves bonding together small pieces of wood from relatively young, fast-growing trees that can be produced very quickly. The result is large panels, beams and columns from which large structures can be built. Existing buildings using CLT go up to 30 storeys, and an 80-storey mass-timber construction is now being conceptualised in Chicago.
Contrary to what one may think, mass timber is not a high-risk material for fire. Because wood burns so predictably, engineers are able to predict exactly when the charred layer will suffocate the fire and protect the central core to ensure it is structurally stable even after a fire.
Timber is considerably lighter than concrete structures, so foundations can be lighter and therefore use much less material. Build times can be up to 70 percent faster – which means quick delivery times and lower project costs for developers. It is also more thermally efficient, structurally stronger than concrete and steel, and has been shown to have both physical and psychological benefits.
A market for sustainable material
The use of mass timber not only lessens the environmental impact of new builds but also creates a market for the material that, if administered responsibly, can contribute to increasing forest cover and economic opportunities.
With well-managed agroforestry plantations, wood can be grown quickly, used productively and harvested and replanted in a sustainable and lasting way – creating an incredible carbon cycle for the planet. Investment in this area will also stimulate better land use for wildlife and ecosystems, and create jobs for local communities.
In the East Africa region, a surplus of sustainable supply is expected to come online over the next 10 years. With the right investments and safeguards in place, there is an incredible opportunity to establish a safe and healthy forest economy in the region.
A compelling case for adaptive reuse
Prospects for innovation in sustainable building apply not only to greenfield developments but also to repurposing assets. In fact, this may be where the biggest potential to make an impact lies.
Following the COVID-19 pandemic, many industry players have been forced to review their property portfolios as certain assets lost their value due to low (or no) occupation. As a result, the idea of adaptive reuse – repurposing existing buildings for different use – has quickly gained ground. In many cases, it is far more cost-effective than ‘building new’.
Across Africa, we are seeing a great deal of activity in this area. Commercial properties are being repurposed for a range of uses, from affordable housing to education and healthcare on one end of the spectrum, to logistics and warehousing facilities and data centres on the other.
Sustainability should be an overarching principle of redevelopment
The environmental cost of demolishing and replacing buildings is also significantly higher than repurposing them, particularly when embodied carbon is factored in.
Developers involved in repurposing and adaptive reuse projects in Africa and globally have an opportunity to take these benefits even further by making sustainability an anchor of redevelopment, applying innovative approaches that significantly reduce environmental impact during reconstruction and over the longer term.
Building to a new code
Reversing the trends that led to the climate emergency we are facing will require a conscious and concerted effort by all stakeholders. The full potential of sustainable building technologies and practices can be realised only when they are widely adopted as an industry norm and incorporated into national building codes.
To change the narrative, we need to start by changing perceptions and behaviours.
Case study: Solana, Uganda
A vision and plan for the long term
With a mandate to invest in various asset classes for its members, Uganda’s National Social Security Fund (NSSF) has a small but high-profile real estate portfolio. Solana Lifestyle and Residences Project, a 600-acre lifestyle and residences development 15km outside Kampala, is a flagship project for both the NSSF and the country. The land was initially intended for low-cost housing but had appreciated in value significantly since it had been purchased. The NSSF, therefore, decided to work with consultants in Uganda and South Africa to reassess the potential of the site and how best it could be used.
As the lead consultant on the project explains, the NSSF was committed to exploring new approaches that went ‘beyond the building’. This, together, with extensive community engagement and the collaboration of a multidisciplinary team, was crucial to addressing the challenges of planning sustainable, long-term development in the context of rapid urbanisation.
A cornerstone of the approach was to incorporate green building principles into the design from the start. The team considered a broad range of factors, from land use and geology to resource management. The development follows the organic topography of the site, which includes a natural ridge and wetland. At the centre is a ‘green space’ with cycle paths, walkways and other features that can be enjoyed by the surrounding community.
In an effort to bridge demographic divides and bring communities together, a mix of different housing types (from entry-level to upmarket) and commercial and recreational facilities have been planned. As the first development of this nature in Uganda, Solana Lifestyle and Residences project is considered to be highly innovative – and serves as an example of what can be achieved by committing to a new course.
This article is based on a panel discussion held during the Green Building Council of South Africa’s Green Building Convention, 2 – 4 November 2021.