There’s been an important focus on green buildings in the world this month (September 2020), so we must ask the question of whether buildings can truly be certified green and sustainable if most of the materials used are not.
Look at all the concrete and cement that goes into your average office block or residential property. Reputedly the most unsustainable material in the world. To make one tonne of cement, for example, involves the production of at least one tonne of CO2 emissions.
Put on a global scale, cement production accounts for 7% of global carbon emissions.
A piece of good news this week came from the world’s largest cement maker LaFargeHolcim, which set the target to reduce its direct and energy-related emissions by 21% by 2030.
But that’s tackling what’s involved in the manufacture. Add to that the hundreds and thousands of cement mixer trucks carrying the stuff to building sites around every city.
While there is a conscious move by the industry to produce what’s called “green cement”, what’s more important is to find ways to use much less cement and concrete in construction.
But before we go into that, what about the other major component in construction: Steel.
The iron and steel industry has made big strides to improve energy efficiency but still accounts for between 6–7% of global CO emissions. Of course, we do see metals being recovered and recycled more, so that helps. But it still accounts for far too much of the embodied carbon in a building.
With the high carbon footprint of cement and steel production – and its transport to building sites – the challenges these industries face might seem insurmountable.
So that’s one very good reason to see timber as a compelling third option.
Timber is one of the few renewable construction materials and, by its very nature, the production of wood via photosynthesis removes CO2 from the atmosphere. It’s also been used in buildings for centuries, so it has history on its side.
An important report released last year – Rethinking Timber Buildings – from the professional firm Arup puts all this in perspective:
“Forest enhancement is seen by many governments as a crucial part of their emissions mitigation strategy, as trees absorb carbon from the atmosphere to grow.
Timber is also less carbon intensive to manufacture, transport and erect than steel and concrete structures. Therefore, increasing the use of timber in our buildings will reduce the carbon impact of construction.”
At home and aboard, the pressure is on the construction industry to come “clean and green”. While the global pandemic has hit the industry hard, bringing to a sudden stop many major projects everywhere, the pause should help the industry to relook at what goes into buildings and how to make a change for the good.
The World Green Building Council admits that globally, buildings account for 39% of all emissions of greenhouse gases. This month it’s been putting a strong emphasis on emissions with its Act on Climate campaign.
“Now is the time to tackle the climate crisis. Countries worldwide are declaring climate emergencies and industry awareness and accountability are at all-time highs. With leading businesses demonstrating how to achieve net zero carbon emissions, governments must step up, go above and beyond to create better buildings for everyone, everywhere.”
The World Green Building Council’s network of Green Building Councils and partners are showcasing examples of global industry leadership. They are delivering a coordinated, collective voice of the industry to demonstrate the existing leadership in the net-zero building movement, and are calling for bolder and more ambitious regulation to unlock these solutions.
Net-zero carbon buildings is a noble aim, maximizing the use of emissions-free renewable energy and making buildings much more energy efficient.
But how to reduce the “embodied carbon” in all our buildings?
The WGBC admits: “Embodied carbon refers to the carbon that is released during the material manufacturing and transportation process and the construction and deconstruction process of a building’s lifecycle.”
In other words, the carbon emitted during the “before use” and “after use” stages of a building’s life. This accounts for 11% of the total 39% of carbon emissions globally from the building sector, and in new buildings, those emissions are occurring right now.
As part of its carbon management strategies, CDL in Singapore, for one, has implemented a science-based approach to setting reduction targets for carbon emissions intensity. In 2018, CDL was the first Singapore property company to have its carbon reduction targets validated by the Science Based Targets initiative (SBTi).
CDL has raised its carbon emissions intensity reduction target to 59%, from the previous 38%, across its Singapore operations by 2030 from base-year 2007. For its developments, CDL has committed to using sustainable building materials, instead of their conventional equivalents, to reduce embodied carbon by 24% by 2030.
Is timber the answer? We definitely think so. Where responsibly sourced and sustainably forested timber is used for construction, it definitely reduces significantly the embodied carbon, but also makes the building better insulated, much more energy-efficient and a building that is remarkably more healthy for its occupants.
Singapore’s leading business in timber construction is Venturer, which was established in 1995 by Kevin Hill. Since then it’s completed over 100 construction projects in markets all over the globe, using sustainably sourced timber from forests on every continent.
From its earliest project, when it built a heavy timber frame at the Singapore Botanic Gardens to the challenge of completing the world-famous deck at Marina Bay Sand’s Skypark, Venturer continues to grow from a traditional timber framer and modular decking specialist into a BIM integrated, Mass Timber specialist of today.
Double Helix Tracking Technologies has worked with Venturer and other companies to verify timber used in the construction of many projects large and small, in Singapore and further afield.
One very special project we worked on – together with architects Ong & Ong – was the Singapore Sustainability Academy at CDL’s Central City Mall, as a showcase of sustainability in construction in Southeast Asia.
Panels & Furniture magazine, reported at the time (August 2017):
“Wood is an ideal material because it is light; it minimises load on the structure. This method also raises productivity—in this case, by 30%, saving about 130 days of work. It also reduces on-site pollution to a minimum, resulting in a cleaner and safer worksite.”
Currently, Venturer is working to achieve PEFC Project Certification on a number of timber building projects in Singapore and the region. With our help, this certification process is combined with full traceability. Every step of the way materials are tracked from forest of origin to the building site.
And all of this information is made available through a recently launched digital platform, in partnership with Sourcemap and Bluenumber, to different stakeholders such as project managers, company leadership, investors, and even end-users.
DoubleHelix’s role is to help leaders in the industry be confident in the timber products they are bringing to market, which is achieved through better visibility, understanding and control of their supply chain practices. This is no hit and miss affair. It’s consistent and it’s transparent.
If timber is to become the material of choice for buildings now and for a long time into the future – as it’s clearly showing to be – the construction industry and property developers must be assured that it is responsibly and legally sourced, coming from sustainably managed forests that continue to grow and absorb CO2, and it’s tracked every step of the way from forest to the finished building.
That way timber can live up to its claim to be the most sustainable building material for all time.
