“We have a real opportunity to work with industry and lift understanding,” Davidson says. “You need a common language and framework for assessment.
“Through the design process, and even when the business case is being developed, reducing the carbon intensity of projects involves interrogating all the design elements, making changes if needed and using substitute materials if required.”
Davidson says infrastructure projects should have longer-term horizons and balance social, environmental and financial values for the good of the country and community.
Aecom’s latest Sentiment survey asked respondents how much consideration was given to sustainability and resilience in planning buildings and infrastructure.
The respondents ranked transitioning to a lower carbon economy and addressing climate change impacts and risks slightly higher in importance than in 2021.
The consideration to a great extent for climate change had doubled in the last five years, but 30 per cent of the respondents in this year’s survey were still responding to a low extent. The majority, 60 per cent of the respondents, was making moderate responses to climate change.
Worryingly, the response to natural disasters had decreased slightly in importance, with 20 per cent of the respondents saying they considered sustainability and resilience in planning infrastructure to a great extent.
Davidson says everyone saw the impact of the Christchurch earthquakes and the need to ensure buildings and infrastructure are protected and resilient. Over time, people have forgotten about these sorts of events because of cost pressures and where to put the investment dollar. Infrastructure projects are still being built in vulnerable areas.
The Sentiment survey did reveal strong support for planning and resource management systems to ensure buildings and infrastructure are placed in suitable locations away from rising sea levels and areas of frequent flooding, with several actions to address climate risks already under way.
Some respondents called for greater unity between local and central governments on managing the main issues and ensuring that funding and opportunities for communities are evenly distributed. Taking on climate change will require greater collaboration and facilitation from the industry.
Respondents also cited a lack of knowledge within the construction sector on how to deliver on ambitions such as net-zero carbon emissions and climate change mitigation.
The Government has now published its National Adaptation Plan for climate change, setting out a proposed future work programme and indicating priorities for the next six years.
The Sentiment survey found many initiatives and projects are new to the infrastructure industry and will require international skills and local upskilling.
Davidson says infrastructure sustainability and resilience is similar to the workplace health and safety journey.
“Its application is currently inconsistent, and we are seeing variations in capability.
“It is about building resilience around infrastructure for tomorrow and decades ahead, and taking warmer temperatures, extreme weather events and rising sea levels into account when making wise decisions on where buildings are located.
“We can look to decarbonise the infrastructure we are designing by stripping out the embodied carbon and using different materials, just concrete and steel. This works best when infrastructure is designed from the start to minimise the impact, so it is taken into consideration when it is delivered.
“The City Rail Link is one good example of that,” Davidson says.
Low-carbon concrete mixes are now coming onto the market, and recycled, anti-corrosive plastic can be encased in concrete. Timber wasn’t part of the conversation 10 years ago for large-scale infrastructure projects, especially road projects, he says.
The Auckland City Mission building was redeveloped with locally-sourced cross-laminated timber as the main structural system. An exterior cross-brace provided lateral stability as well as a strong aesthetic and Māori identity.
The consent included retaining the original timber structure and heritage fabric of the Prince of Wales Category B building.
The cross-laminated timber system provided a robust, lightweight, prefabricated response, and minimised the building’s embodied energy, construction times and on-site labour.
When the Naenae Pool and Fitness Centre and community hall in Lower Hutt were demolished, about 80 per cent of the materials were repurposed or recycled. The local community secured memorabilia that was donated or retained for reuse in the new facility.
Wood was recovered and donated to Menzshed New Zealand for repurposing, and the existing pool structure has been recycled for use in the construction of the new facility.
Engineers at Aecom re-aligned the route of an expressway in New South Wales to make it shorter and use fewer materials.
Recycled concrete went into the road base, creating significant cost savings for the community — it was taxpayers’ money that could be diverted into other programmes.
Project Emissions Estimate Tool
Aecom developed the Project Emissions Estimation Tool (PEET) for Waka Kotahi (NZ Transport Agency) and Auckland Transport.
The tool is used in the early stages of planning and designing land transport infrastructure to provide a high-level estimation of the greenhouse gas emissions through the life cycle of the project, including construction, operation and maintenance.
Davidson says PEET, which is widely shared, helps people understand the carbon intensity for the different design options.
“It’s a kind of benchmark for people to evaluate and monitor and tell the story of why they chose a particular option.”
He says there is a cost of carbon, and this needs to be factored into the conversation.
“PEET leads us to the next obvious question: how do we put a dollar value to carbon emissions and make it part of the pricing regime? The aim of the game is to reduce the carbon footprint across infrastructure projects.
“We can bring global expertise to planning and designing projects and create a transparent and consistent approach across the country. By putting a dollar value on the traditional carbon intensity impact, we have the opportunity for driving innovation.”
New research
An Aecom paper on the cost of carbon in transport infrastructure appraisal suggested countries should work towards a universally-agreed method of estimating the value of carbon. This is likely to help narrow the gap in the values of carbon used in different economies. Clarity from appraising organisations on the definition of carbon emissions related to construction, maintenance, and operation such as lighting and control systems, and embodied carbon will help better transparency of assessments.
Davidson says the UK is now recommending that the cost or monetary value of carbon be included in the appraisal process or business case for infrastructure projects.
“If the cost is too high, then is there an alternative? The best outcome for the environment may be not to build infrastructure at all.”
When looking at a problem and a solution, is there a non-infrastructure way? Davidson says transport infrastructure is sized for peak traffic flows, but Covid-19 showed that people can be flexible when they travel.
“Demand management or congestion charging, such as in central London, can help smooth out the peaks.
“The congestion money can be used for more sustainable projects — it’s a win, win situation,” Davidson says.
According to Aecom, the biggest win for New Zealand would be a renewed focus on cross-industry collaboration to deliver on the national net-zero targets by 2050.
· Aecom is an advertising sponsor of the Herald’s Infrastructure report.
