Sustainable mass timber construction: Transforming cities, forests and livelihoods

The window to limit the global temperature rise to 1.5°C is closing rapidly. To avoid catastrophic climate change, there must be rapid and sustained reduction in greenhouse gas emissions across all sectors by the end of this decade. 

Across Africa, communities that have contributed least to global emissions are set to be the most vulnerable to the impacts of climate change. However, some of these communities are also predicted to see rapid growth over the coming decades. We must decarbonise in a way that allows us to realise the full potential of our economies.

Sustainable construction: The opportunity 

As populations rise, homes, cities, and infrastructure will grow with them. There will be two billion people in Africa by 2050, half of whom will live in cities. And by 2060, 35 percent of all global construction will take place in Africa.

Globally, the construction sector is responsible for 39 percent of carbon emissions. Conventional building practices that rely on cement and steel risk making African urbanisation a leading cause of global heating. However, there is another way. Construction could instead be at the forefront of the global decarbonisation agenda, while simultaneously catalysing economic and social impacts across the value chain. 

Mass timber construction

Mass timber is a type of engineered wood made from compressed wood panels glued together. This processing creates a material that is 15 times stronger than steel, while also being significantly lighter, more flexible, and more thermally efficient. Not only does this sequester carbon for decades, but it also bypasses traditional, resource intensive materials. Every cubic metre of mass timber used instead of concrete keeps two tonnes of carbon-dioxide out of the atmosphere. 

If just 20 percent of sub-Saharan Africa’s housing boom was met by mass timber construction by 2050, over 100 million tonnes of carbon-dioxide could be saved annually. If supplemented with other innovative building practices such as recycled steel and cement produced with green hydrogen, emissions could be cut even further.

The finished mass timber panels can be built to the exact specifications of a building, cutting construction time, costs, and emissions. Structurally, mass timber is more fire resistant, earthquake resistant, and energy efficient than its concrete counterparts.

This opportunity has the potential to generate millions of jobs across the continent, while demand for wood will drive the development of a sustainable domestic commercial forestry sector, simultaneously meeting environmental, social, and economic needs across the region.

Aligning forestry and sustainable construction

Sweden’s experience demonstrates that commercial forestry and the expansion of forest cover can go hand in hand. During the 20th century, Sweden derived much of its industrialisation and economic growth from forests and forest products, while at the same time doubling its forest cover to 70 percent of the country’s surface. The demand for forest products, efficiency measures and value-addition technologies, together with policies for replanting, have made this possible.

 In the 21st century the introduction of mass timber technologies has catalysed the transition to renewable construction materials. In 2021, Sweden unveiled a 20-storey cultural centre, music hall and hotel, all made in mass timber, with the carbon emissions generated from construction totalling to less than the amount stored in its structure.

Mass timber in Africa

CPS Zanzibar, a property development company, is one of the first to realise the potential of this opportunity in Africa, developing Fumba Town and The Burj Zanzibar. The first is a mixed-price 5,000-unit housing development, while The Burj is set to be the world’s tallest timber building. Together, they make up an innovative eco-town, providing a mix of affordable and luxury housing, and demonstrating the speed and quality of timber construction. 

However, the project has had no access to locally produced timber. All the timber used to build Fumba Town was imported from South Africa and Europe, adding roughly 25 percent to the building cost.  

In fact, the investment was only enabled by a combination of public-private partnership (PPP) lease agreements and a Special Economic Zone, allowing the development to still run at a competitive price. While the impact of strong PPPs is transformative, for mass timber to reach its full potential for the region, the development of domestic timber production is vital.  

Regional manufacturing

Plantations play a crucial role in the mass timber opportunity. However, it’s the region’s manufacturing capabilities that continue to limit the forestry sector from reaching its full economic potential.

Engineered timber requires several processing steps. Raw timber of the right quality needs to be kiln dried, after which it is glued together. This high-quality processed construction timber is worth three to six times as much as low grade sawn timber. However, throughout Africa, plantation capacity exceeds high-quality processing capacity, creating a bottleneck.

Firms across Africa are working to remedy this. New Forest Asset Management is leading processing investments in Uganda and Tanzania, unlocking access to higher value markets for farmers. Criterion Africa Partners is another key player, investing across the value chain, from plantations to manufacturing and wood waste processing to release biomass energy, demonstrating the transformative potential high-value processing can have across the entire value chain.

PPPs

PPPs can play a crucial role in bridging the gap. But for PPPs to be successful, it is critical to balance the needs of investors, government, and local communities.

In Ghana, the government used long-term leases to unlock large-scale investment in tree growing and high value timber processing, while also introducing policies to incentivise and reward smaller-scale community planting.

Uganda also implemented long-term leases with an explicit strategy to support quality planting by small and medium-scale growers alongside larger-scale industrial operators. Financed by the private sector, the impact has been huge, with over 100,000ha of forestry planted over the last 20 years, 75 percent of which has been planted by small and medium-sized growers.

East Africa 

In Nairobi, the population is expected to be double its current size by 2050. Dar es Salaam is predicted to be a city of over 70 million people by the end of the century. Acting pre-emptively, in Nairobi alone, 2.97 million tonnes of carbon-dioxide could be saved by 2040, cutting construction emissions by 40 percent. 

By working with governments, private and public sector players can find solutions to help capture this opportunity, leveraging renewable home-grown resources to transform our cities, our economies, and the livelihoods of millions of people across the continent. 

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