3 February 2022
World Engineering Day for Sustainable Development was proclaimed by UNESCO at its 40th General Conference in 2019 and is celebrated on 4 March each year.
The day offers an opportunity to highlight engineers and engineering’s achievements in our modern world and improve public understanding of how engineering and technology are central to modern life and sustainable development.
At Tonkin we provide exceptional consulting services, while also staying true to our values. We care about people, the communities we’re a part of and the world we depend upon.
That’s why we strive to be at the forefront of delivering projects that align with the key theme of this year’s World Engineering Day; “Build back better – Engineering the future”.
Structural engineering – one of Tonkin’s key capabilities – is an area of engineering that provides both challenges and opportunities when it comes to sustainable development. While Australia is making progress on climate action, some may argue that collectively we’re falling behind in the race to reduce the impact of our built environments, especially in comparison to other regions around the world.
For example, in 2008 European leaders agreed to cut their greenhouse gas emissions in 2020 by 20% from 1990 levels. This was achieved three years early. In 2014 they agreed to a 40% reduction by 2030, they have subsequently upped this to a 55% reduction from 1990 levels by the year 2030. The EU has enshrined Net Zero Carbon Emissions by 2050 into Law.
The day offers an opportunity to highlight engineers and engineering’s achievements in our modern world and improve public understanding of how engineering and technology are central to modern life and sustainable development.
At Tonkin we provide exceptional consulting services, while also staying true to our values. We care about people, the communities we’re a part of and the world we depend upon.
That’s why we strive to be at the forefront of delivering projects that align with the key theme of this year’s World Engineering Day; “Build back better – Engineering the future”.
Structural engineering – one of Tonkin’s key capabilities – is an area of engineering that provides both challenges and opportunities when it comes to sustainable development. While Australia is making progress on climate action, some may argue that collectively we’re falling behind in the race to reduce the impact of our built environments, especially in comparison to other regions around the world.
For example, in 2008 European leaders agreed to cut their greenhouse gas emissions in 2020 by 20% from 1990 levels. This was achieved three years early. In 2014 they agreed to a 40% reduction by 2030, they have subsequently upped this to a 55% reduction from 1990 levels by the year 2030. The EU has enshrined Net Zero Carbon Emissions by 2050 into Law.
Much can be achieved when the right drivers are in place.
Along with companies, cities and financial institutions, more than 130 countries have now set or are considering a target of Net Zero by 2050. Australia currently sits in the ‘pledge/declaration’ bracket which falls short of having a policy document or a Law. It is likely that this will change in the future given the international pressure for developed nations to lead this transition to a low carbon economy.
From a structural engineer’s perspective transitioning to low carbon design solutions will be necessitated either by new legislation and/or in the design briefs from our clients. Construction materials alone are responsible for 10% of global carbon emissions so business as usual for the construction sector will not be an option moving forward.
Through our working relationships with our clients and stakeholders, engineers are in a great position to influence the design brief. We can highlight issues and suggest courses of action at the earliest opportunity giving the best chance of leading to sustainable design outcomes.
Outlined below are some of the common principles that should be considered during the design and construction of new building and infrastructure projects.
Along with companies, cities and financial institutions, more than 130 countries have now set or are considering a target of Net Zero by 2050. Australia currently sits in the ‘pledge/declaration’ bracket which falls short of having a policy document or a Law. It is likely that this will change in the future given the international pressure for developed nations to lead this transition to a low carbon economy.
From a structural engineer’s perspective transitioning to low carbon design solutions will be necessitated either by new legislation and/or in the design briefs from our clients. Construction materials alone are responsible for 10% of global carbon emissions so business as usual for the construction sector will not be an option moving forward.
Through our working relationships with our clients and stakeholders, engineers are in a great position to influence the design brief. We can highlight issues and suggest courses of action at the earliest opportunity giving the best chance of leading to sustainable design outcomes.
Outlined below are some of the common principles that should be considered during the design and construction of new building and infrastructure projects.
Industry is leading the charge for the transition to low carbon materials in Australia with the Materials and Embodied Carbon Leaders Alliance (MECLA) bringing together clients, designers, manufacturers and contractors to drive the change. MECLA have a multi-faceted approach to the problem with working groups on demonstrating demand, defining best practice embodied carbon evaluations, defining procurement guidelines and supporting the materials supply side.
Build with the future in mind
Ensure that end of life is considered from the start. How easily can materials and components be recovered for re-use or recycling? Composite materials are usually difficult to separate into their constituent parts. Can the building be easily disassembled, perhaps for reassembly elsewhere? Use mechanical fixings where possible to allow for easy removal and repurpose.
Good record keeping and as-constructed drawings together with physical marking on structural members could allow a future engineer to re-use these instead of sending to recycling or landfill. Adopting these principles will allow us to make best use of steel’s circular economy potential.
Generous allowable imposed loadings and large structure free spaces will typically allow a building to cater for a wider variety of potential uses in the future, coupled with durable materials and detailing could see a structure used easily for 100 plus years. Although this may seem to go against what has been said above, it may sometimes be the most sustainable solution over the longer term.
Collaborative building
The best value design in terms of sustainability will involve the whole design team and client. The biggest impacts on a project are typically made at the inception phase so this is when the conversation needs to begin.
To what extent does the choice of structure impact on the energy use of the building? Is it better to have a little more on the embodied carbon side of the emissions equation and to reduce the operational carbon cost of heating and cooling?
Providing ample spaces and easy access to building services will allow for their eventual replacement helping to perhaps prolong the life of the building structure in the future.
Build less from scratch
The simplest way to reduce embodied carbon in a structure is to reduce the amount of materials by building less in the first place.
Is refurbishment an option? Could an existing structure be strengthened and be repurposed? Can existing materials be re-used? Are existing foundations adequate for the proposed loads? This requires a change in mindset from both the engineer and the client. This may require significant investigation work upfront to determine what is possible and allow these existing constraints to inform the low carbon design. Effectively, the engineer is more so being engaged to justify the existing, rather than design the new. In many ways, this is more challenging, as the engineer becomes part detective and part designer.
With achieving a low carbon outcome being a key driver of the design process, it should be compared with the client’s brief to determine how they align. For example, are long span open spaces really necessary at the expense of having a carbon heavy design? It is the role of the engineer to engage the client in this conversation and use our expertise to highlight the potential options that may be available.
Build lean
Reduce loads where possible. What loads are really required to meet the brief? Take advantage of available structural depths for more efficient member sizes. Use the most structurally efficient material in each location.
Examine serviceability criteria such as deflections if they govern the design. Can these be relaxed?
Structural members should be designed for 100% utilisation rate. This can be achieved by having somewhat regular layouts and repeating modules where possible. Designs should be revisited after concept stage to see how member utilisation rates can be increased while still maintaining a rational design solution.
Build wise
Ensure that longevity is considered in design. Typically, we design for a 50-year design life but this is in reality just a statistical calculation. Many buildings can last much longer if designed and detailed correctly, allowing for maintenance and replacement of components as required.
We should look at Design for Manufacture and Assembly (DfMA) and Modern Methods of Construction (MMC) where possible to utilise factory precision and avoid site wastage. The construction industry certainly hasn’t seen anything like the levels of productivity gain over the years that we have seen in other industries like car manufacturing. Much of what is currently done on site is just because it’s always been done that way. There is inertia to change in the industry that must be overcome.
Low carbon materials
Use lower embodied carbon materials where possible. At the scheme design stage conduct some quick calculations of the embodied carbon in various structural schemes to identify the optimum solution. Often this will identify the carbon intensive parts of the project and give the design team the opportunity to design them out at an early stage.
We also need to look at new low carbon materials. This will require engineers to be more adventurous as it is unlikely that our codes of practice will be able to keep pace with the flurry of novel materials expected to hit the market.
While we wait for these new materials a preference for timber should be considered to encourage more supply to come online. Growing timber sequesters carbon from the atmosphere and we can lock it away in our buildings. This is a great option as we try to phase out the carbon intensive materials in the near term. Provided it doesn’t end up in landfill at the end of life it is an excellent material.
Although steel is almost 100 percent recovered for recycling, the projections are that we will still need to increase the production of carbon intensive virgin steel for the foreseeable future.
Concrete can be made with lower carbon cement replacement materials, but these are by-products of other industries like steel production. They are also a limited resource and overall should not be relied upon to get the global carbon reductions required.
In summary
As engineers, we have a responsibility to drive the changes that will help ensure our cities and communities are sustainable, now and for future generations. It was engineers that first unlocked the power of fossil fuels to use in engines so we as a profession now have a special burden to put things right.
In summary
As engineers, we have a responsibility to drive the changes that will help ensure our cities and communities are sustainable, now and for future generations. It was engineers that first unlocked the power of fossil fuels to use in engines so we as a profession now have a special burden to put things right.
Together with our clients and architects, engineers have a growing responsibility to deliver projects that reduce the carbon emitted during a building’s life cycle including all the phases of construction materials production, transportation, installation on site, as well as their disposal at end of life.
At Tonkin we take this responsibility seriously and as an organisation have signed up to Engineers Declare a Climate and Biodiversity Emergency. We train our staff in low-carbon design and assess our designs against international carbon reduction targets.
Engineers are in a unique position to guide the design process and to have notable impacts on the amount of greenhouse gases released into our atmosphere during the development of our built environment. On each and every project we have an opportunity to save many times as much carbon as a typical person could by making every possible green choice available to them over their entire lifetime.