Decarbonizing the Built Environment: Sustainability techniques

The construction of our buildings and infrastructure impacts the environment due to high levels of carbon emissions and climate change. The growing world population and urbanisation highlight the need to reduce carbon footprints in construction. This article will explore different techniques, standards and technologies that can help us achieve a sustainable future by decreasing carbon emissions in the built environment.

Table of Contents

Understanding the challenge

As per a McKinsey report, the construction and infrastructure of buildings are responsible for about a quarter of the world’s greenhouse gas (GHG) emissions. Approximately 28% of global carbon dioxide emissions are attributed to heating, cooling, lighting and powering buildings, according to the International Energy Agency (IEA). The production and transportation of construction materials add to these emissions. Hence, a comprehensive approach is needed to address these concerns in both new and existing buildings.

Energy efficiency in building design and construction

To achieve decarbonisation, it is crucial to enhance the energy efficiency of buildings. The implementation of passive design principles, including optimal orientation, natural lighting and ventilation, can considerably lower energy consumption. Furthermore, utilising high-performance building materials and insulation can enhance energy efficiency. The built environment can be decarbonised by using renewable energy sources, such as solar panels and geothermal systems.

For energy-efficient buildings, architects and engineers must adopt integrated design approaches and utilise advanced modelling and simulation tools to assess a building’s energy performance and identify opportunities for energy conservation. Building information modelling (BIM) technologies allow designers to analyse multiple design options, enhance energy efficiency and minimise environmental impact.

Retrofitting and modernising existing buildings

A large portion of our constructed environment comprises pre-existing buildings with a low energy efficiency rate. By retrofitting these buildings with energy-efficient systems, a significant emission reduction can be achieved by upgrading insulation, replacing outdated HVAC (heating, ventilation and air conditioning) systems with energy-saving alternatives and installing smart energy management systems.

There is a need for comprehensive guidance for retrofitting existing buildings through passive measures. Apart from physical upgrades, it is important to promote behavioural change and educate people about energy-efficient practices. Encouraging energy-conscious behaviour, such as turning off lights when not in use, using natural ventilation instead of air conditioning and maintaining energy-consuming equipment, can lead to desired energy reduction goals. A well-designed occupant engagement program is crucial in achieving these goals.

Sustainable construction materials

In India, embodied and operational emissions from the built environment are about 40% and 60%, respectively. This is primarily due to carbon-intensive building materials, such as concrete and steel. The construction industry must use eco-friendly materials and low-carbon alternatives to promote a sustainable environment. Mass timber is a prime example of sustainable construction materials because it stores carbon, contributing to carbon sequestration. Other innovative materials, like bamboo, hempcrete, green cement and recycled plastic composites, offer low embodied carbon while ensuring durability and high performance. By manufacturing building components off-site with sustainable materials, resources and waste can be reduced.

Circular economy principles are valuable in decarbonising the construction industry. Building for disassembly, reusing materials and reducing waste generation can help achieve this goal. The construction industry should adopt and scale up low-carbon technologies and materials. As detailed in the McKinsey report, there are multiple opportunities to reduce operational emissions by up to 90% and embodied emissions by up to 60% if these are implemented at scale. Additionally, this approach can create new economic opportunities and green jobs.

Leveraging advanced technologies

New technology has the potential to help reduce carbon emissions in buildings. Smart grid systems can integrate renewable energy sources and optimise energy usage by allowing buildings to communicate with the grid. Demand response mechanisms can adjust energy usage based on grid conditions and pricing signals.

Internet of Things (IoT) devices and sensors collect energy usage data, which can help building owners and occupants make informed decisions. Occupancy sensors can automatically adjust lighting and HVAC systems based on the number of people present in a room. Building automation systems can optimise energy usage based on occupancy and environmental conditions, promoting energy efficiency.

Machine learning algorithms can constantly improve energy models and predict occupant behaviour patterns, leading to optimised energy consumption and reduced emissions.

Policy and financial incentives

The decarbonisation of the built environment is heavily influenced by government policies and financial incentives. An effective way to promote sustainable building practices is by implementing building codes and standards for the assessment and reporting of embodied carbon limiting and maximum carbon emissions, addressing operational carbon from the initial design stage of new buildings, the measurement of building performance through carbon emissions as a complementary metric to energy consumption and prioritising energy efficiency.

The Royal Institution of Chartered Surveyors (RICS) recently launched the second edition of its Whole Life Carbon Assessment for the Built Environment (WLCA) standard. By using the WLCA 2nd edition, professionals can estimate the amount of embodied, operational and user carbon emitted throughout the life of a built asset.

In addition, providing fiscal incentives for energy-efficient retrofits, installations of renewable energy sources and sustainable buildings can make these projects financially feasible. By working together, governments, businesses and financial institutions can provide the necessary support for environmentally friendly construction.

To achieve a greener future, it is crucial to decarbonise the built environment. This involves addressing the challenges posed by the built environment’s contribution to carbon emissions and climate change through a comprehensive approach. This approach should include reducing embodied carbon and operational carbon by improving energy efficiency in building design and construction, retrofitting existing buildings with energy-efficient technologies, using sustainable construction materials, adopting advanced technologies and implementing supportive policies.

( The author is the Senior Public Affairs Officer – RICS.)

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