Mass timber: a green building solution?
Updated: May 19
The truth is, there is no simple answer. Mass timber is undoubtedly an exciting step in the green building revolution and we are excited to see its developments, especially in Africa. We hope you will read to the end to get a rounded idea of the story!
What is Mass Timber?
Mass timber, often called engineered timber, is a category of wood products made from smaller boards which are laminated into thick structural elements. It can take the form of Cross-Laminated Timber (CLT) panels, Glued Laminated Timber (Glulam), Laminated Veneer Lumber (LVL), etc.
The material is lightweight, meaning it requires smaller foundations and is easier to transport. Components are also typically assembled in the factory, decreasing construction time. The resulting product is long-lasting and fire-resistant. Most importantly, timber production has a significantly lower environmental impact than concrete or steel alternatives.
Gensler recently released an article hailing this as "the forerunner in the biogenic material revolution". It describes how the cross-industry cooperation between design, construction, forestry and conservation industries has pushed the awareness and acceptance of this material like no other.
We should follow mass timber’s example and use cross-industry collaboration, advocacy, and education to promote the increasing array of new biomaterials in the building industry. - Erik Barth, Gensler
Image source: ArchDaily
Is it a viable solution for green building?
IIED Report: Mass(ive) Timber Benefits in Africa
The International Institute for Environment and Development and Dalberg published a report in 2022 detailing the massive potential benefits of timber construction in Africa. Some highlights include:
Support affordable housing, as timber construction usually follows a modular design, allowing for easier direct repairs and offering longer-lasting, high-quality living spaces compared to cement and steel.
Create jobs and drive economic development, with the potential to generate millions of employment opportunities and contribute billions of dollars to the bioeconomy.
Grow sustainable foresty sector and open opportunities for export to global markets.
Promote 'carbon sink', as forests remove carbon dioxide from the atmosphere and the timber industry produces less carbon compared to steel and concrete construction.
With thermal properties well suited to hotter climates, mass timber can unlock both energy savings and lower construction costs. With 25% faster construction times and being US$14 cheaper per square foot than concrete and steel construction, mass timber provides an important opportunity for expanding Africa’s housing stock.
IIED Report: African timber cities: carbon sinks with development benefits?
Feasibility in South Africa
In 2020, engineering consultants Zutari conducted a study examining the economic feasibility of a multi-storey mass timber building in South Africa. The research found local timber stocks currently insufficient (and will be for at least the next few decades), meaning imported timber would be needed. However, the ultimate outcome was that mass timber building is financially feasible in South Africa. The report called for investment into sourcing high-grade structural timber and equipment for the processing and production of large beams.
Case Studies in Africa
The Burj Zanzibar
The tallest timber tower in the world is going to be built in Fumba Town, Zanzibar. At 28 floors, 96 meters high, the tower is scheduled for completion in 2026/7.
Image source: ArchDaily
German architects OMT had this to say:
The demand for timber as a construction material needs to grow before challenges in the local timber value chain can be overcome...OMT’s projects in Africa aim to create more awareness of the potential for mass timber in construction. - Leander Moons - founding partner of OMT architects
For more on Burj Zanzibar, watch a video.
Flooring and other structures
As flooring industry professionals, we have seen a huge uptake of mass timber used in flooring - both internal and for decking. Click the images below to check out some case studies from around Africa.
Criticism of mass timber
Is mass timber starting to sound like a miracle cure for dirty construction? Though it may be part of the solution, critic Benjamin Kromoser reminds us that it is not a simple answer. There never is.
In an interview with Dezeen, Kromoser calls for a relook at our relationship with growth: He notes that although mass timber and other products are important, endlessly extracting resources is never 'sustainable' and we need to use design and innovation to use fewer materials in general.
So... it's not just a matter of replacing concrete with wood, but finding clever ways to reuse old materials, decrease our materials needs, and make the most of what we have!
"Timber is a great material, and mass timber where it has its justification is a good thing... But thinking about how the building can be structurally optimised is a really important thing to keep in mind."
Here are some more resources that might interest you:
Timber Revolution: An editorial series exploring the potential of mass timber that asks whether going back to wood as our primary construction material can lead the world to a more sustainable future.
ArchDaily: 50 Projects that Use Engineered-Wood Architecture