The built environment – the buildings, linear infrastructure, and shared places that collectively support our communities – is one of the world’s greatest climate culprits, contributing 39% of CO2 emissions, 37% of energy use, and 40% of material use, globally.[1] To achieve the critical objective of limiting global warming to 1.5°C, stakeholders around the world must reach beyond quick wins and focus on decarbonizing those sectors that are the toughest to abate – including the built environment.
But the world is experiencing the largest wave of urban growth in human history. The global built environment is projected to expand by 2.4 trillion square feet of new buildings between now and 2060. The great challenge, therefore, is charting completely new pathways of planning, design, and construction to ensure that we can reduce and offset the emissions triggered by the built environment, even as it continues to expand.
We must develop and use innovative and sustainable technologies and techniques and rigorously apply sustainable methods and materials to the built environment, leading to enhanced quality of life, economic growth, and greater local skills and job opportunities. We have to embrace a fundamental shift in thinking and recognize that traditional construction techniques, materials, and technologies need to be updated for the net zero era. Then, that becomes a matter of establishing an innovation ecosystem that develops sustainable technologies and practices for every stage of the built environment’s lifecycle: from planning through to operation, maintenance, and repurposing.
In recent research, Dar, Strategy& and PwC explored more than 50 innovations and technologies that – if developed and implemented– could potentially reduce emissions in the built environment by as much as 50 to 60 percent.
Planning for sustainability and resilience
Development or urban planning is an essential pathway to decarbonizing the built environment – given the large-scale, systematic changes that are required. In designing new cities or urban extensions, Dar’s urban planners and designers integrate sustainability into every aspect of a master plan. By focusing on innovations and emerging best practices, it will become possible to elevate sustainability to a even higher level. Measures could include decentralizing power generation – to provide reliable sources of renewable energy generation and to reduce transmission and distribution costs – and building storage for dynamic energy management, perhaps even through the clean-burning hydrogen, reinforced by battery storage systems. Other new practices and innovations that could be implemented include everything from decentralized water generation and recycled roads to sustainably-powered charging infrastructure and even energy-harvesting roads that can generate green electricity to power urban infrastructure.
Taking embodied carbon out of the built environment
Embodied carbon – collectively, the emissions that are directly linked to construction materials and processes – is a significant barrier to decarbonization. Embodied carbon is influenced by everything from the construction materials themselves, their extraction, manufacturing, transportation, usage, and waste disposal and recycling.
When designing a new building, Dar’s designers and engineers focus on incorporating measures that decrease embodied carbon, for example by employing techniques such as design for manufacture and assembly (DfMA) or cradle-to-cradle (C2C) construction techniques. DfMA stipulates designing and engineering buildings off-site (through prefabrication and modular construction), cutting down on construction waste, inefficiency, and risks to workers. C2C construction, on the other hand, causes a substantial reduction in embodied carbon, by focusing on recycling or upcycling construction materials. One such example is reinforcing concrete with recycled plastic, instead of steel, which not only reduces the resources needed to produce concrete, but also provides a powerful alternative end result.
Meanwhile, future innovation in construction materials – for example, by producing green steel or waste-heat-to-power-based cement or photocatalytic self-cleaning concrete or even natural refrigerants for HVAC equipment – is essential and can have very significant impacts on embodied carbon in the global built environment.
Reducing operational emissions
Operational carbon refers to emissions that are caused by processes required to keep buildings and infrastructure powered, cooled, and ventilated. By incorporating energy-efficient equipment and providing passive design measures that reduce the need for lighting or cooling, designers can reduce operational carbon significantly.
However, innovative measures such as dynamic, air-purifying facades and AI-powered building management systems are still needed to make a significant difference in reducing operational carbon. And stakeholders need to carefully investigate and plan for opportunities such as trigeneration (producing cooling, heat, and power from a single renewable fuel input), decentralized wastewater treatment (to reduce costs and energy consumption), and up to decentralized power generation, possibly with green hydrogen for fuel and storage.
A paradigm shift
Decarbonizing the built environment requires stakeholders to make critical decisions, to incorporate existing sustainability measures and to drive forward extensive investments to create the technologies, materials, and power supply sources that will be essential in driving emissions down and paving the way for a world of net zero.
[1] International Energy Agency data, 2021
