Improving energy efficiency in all phases of construction projects
Construction directly or indirectly contributes around 25% of total greenhouse gas and 40% of CO₂ emissions from fuel combustion globally. The delivery of new infrastructure and buildings can bring significant carbon emissions and inefficiencies from powering plant and equipment, undertaking demolition or the transportation of materials and waste. As decarbonising the built environment grows in urgency, with the recent COP27 looking to renew international commitment to translating the ambitions set at COP26 into action, it is critical to boost energy efficiency pre and during construction.
Additionally, with the World Bank predicting energy prices to be around 50% higher compared with 2021, construction costs will continue to be affected, making energy savings even more of a priority. The industry has great scope to improve energy efficiency as well as its environmental impact, but this requires a whole supply chain approach.
Key trends and solutions
Typically, construction sites relied on fossil fuel-based energy but regulations are tightening and governments are setting targets to reach net zero and make harmful energy sources obsolete by 2050. Some contractors have started to shift away from diesel-powered machinery and generators to alternatives that utilise and generate electricity from green energy sources. Off-grid hybrid power and battery storage systems, for instance, offer a seamless transition between harnessing renewable energy from wind and solar power and switching to generators only when necessary.
Apart from construction work, sites include temporary offices, portable units, shower facilities, internet connections and more, with some masterplans requiring them to be in place for up to fifteen years, creating an overwhelming demand on the grid. Again, converting to hybrid power can lead to substantial energy savings over time. The use of ‘green’ hydrogen to run generators with fuel cells is another option and adoption is growing.
Greater use of renewables in construction aligns with wider objectives – from the US working to transition to clean energy, to the EU’s plans to accelerate the expansion of solar and wind, and the UK government’s Energy Security Strategy – and goes a long way to driving energy efficiency, alongside the use of biofuels and more hybrid or electric vehicles.
Focusing on whole life energy efficiency
The potential to improve energy efficiency not just during construction but for the entire lifecycle of a project is strongest before work kicks off, at the design stage. This is when key decisions are made and where contractors and developer/contractors can have more influence over wider supply chain methodology and approaches. It is also wheremeasuring and monitoring can bring the biggest benefits to the project’s environmental credentials.
Construction monitoring can support leaner designs, such as those that use fewer materials with a high proportion of embodied carbon like steel or concrete. It can mitigate the risk of using thinner concrete, check tolerances, and potentially reduce the number of props required. Further, initial baseline surveys can help mitigate any adverse impact on the environment and, for these, we use renewable technology to power monitoring equipment – a huge benefit where development is proposed on brownfield sites as it provides months of continuous power at a specified voltage.
As technology continues to advance, particularly in the fields of AI, automation and machine learning, this will offer new ways to inject more efficiency into developments, from precision surveying and design choices, to materials and construction methods.
Every project inevitably brings its own challenges but the focus must be on making the whole supply chain as sustainable as possible. If minimum emissions are at the heart of the end-to-end approach, we can achieve improved energy efficiency and a greener looking industry.
Tony Selwyn is head of environmental planning at Plowman Craven