Building a Sustainable Future: Green Buildings for a Better Tomorrow
Society for Environment and Sustainable Development
Let^s achieve Sustainable Development Goals
The built environment – the place where people live, sleep, work, and play – is a major source of carbon dioxide. This greenhouse gas traps heat near the Earth’s surface, warming the planet and driving climate change. UNEP's Green Buildings and Climate Change page further noted that every five days the world adds structures equivalent to the size of Paris, however the way we construct and operates buildings is unsustainable. In 2022 building operations and construction activities were responsible for 21 per cent green house gasses and 10 gigatonnes of carbon dioxide, which was 37 per cent of global carbon dioxide emissions as per the United Nations Environment Programme (UNEP) . Reducing carbon footprint of our homes, offices and other buildings is should be part of the more ambitious global efforts to counter climate change.??
How Buildings Lead to Climate Change?
There are two reasons because of which buildings are considered greatest source of carbon dioxide emissions 1. Operational Carbon which include 34 per cent of the world's power consumption required in the form of heating, cooling and lighting the buildings . Most of this energy is generated by burning fossil fuels – like coal and oil – which release carbon dioxide as noted by the UNEP’s Global Status Report for Buildings and Construction . 2. Embodied Carbon represents the millions of tons of carbon emissions released during the lifecycle of building materials, including extraction, manufacturing, transport, construction, and disposal. Concrete, steel, wood, glass, are all examples of materials that contribute to embodied carbon emissions.
International Energy Agency expect 18 per cent of renewable energy use in buildings by 2030, however in 2022 it was only 6 per cent. The global building emissions are increasing by 1 per cent each year which is like adding 10 million cars to the worlds road the report says.
How to reduce building sector emissions?
Unless the world changes how buildings are built and used, there will be little chance of meaningfully addressing climate change, which will lead to, among other things, more extreme weather. UNEP suggests to reduce operational emissions from its buildings by making buildings more efficient, cutting the amount of energy they use for things like heating and cooling through better energy planning and system integration.
Embodied carbon emissions can be avoided by
Building Sector: The Pace and Space
The Global Status Report for Buildings and Construction entitled "Beyond Foundations : Mainstreaming Sustainable Solutions to Cut Emissions from Building Sector" by UNEP reported that since 2010, the total global area of constructed buildings has grown by over 31 per cent and reaching just over 250 billion square meters, with nearly 80 per cent of this being residential. The increase in buildings floorspace is a driver of energy demand for buildings and construction materials. Between 2021 and 2022, total global buildings floorspace grew by two per cent, while energy demand grew by one per cent.
The report further observes that there is slight decrease in the overall expenditure in construction sector in high income countries. There will be 2.7 per cent growth in China and 5 per cent in India. However, these buildings lack any labelling that address energy performance resulting in growing energy demand. The floor area is projected to increase by a further 15 per cent by 2030 with an addition of about 40 billion square meters which is equivalent to five times the current floor area in Indonesia. And more than half of these additions are in regions with hot climates which lacks comprehensive building codes leading to rise in space cooling demand.
Social Impact of Buildings
The built environment can have multiple effects on people various aspects like health, well-being and human rights. These aspects are impacted at every stage of the building and construction lifecycle. However these impacts are rarely measured and addressed because of lack of clarity, recognition and understanding. The buildings and construction sector can play a crucial role in improving social justice and equity. The World Green Building Council's report entitled ‘Social Impacts across the Built Environment’ provides a framework for the building and construction sector to address the social impact across the entire building life cycle. The framework introduces scopes 0-3 to guide the industry in addressing social justice and equity. The goal is to integrate social and environmental sustainability in the built environment and improve decision-making and environmental, social and governance (ESG) reporting in the sector.
Scope 0: Entity and Internal Practices
Scope 1: Building users & site
Scope 2: Community and Surroundings
Scope 3: Supply & value chains
All scopes try to address all the social impact issues ranging from diversity and inclusion, health, comfort and safety, privacy and security, climate impacts during operational, design and construction and manufacturing and end of life cycle of building.
Energy Use in Building and Construction Activities
The share of operational energy in the form of space heating and cooling, water heating, lighting, cooking and other uses accounted for 30 per cent of final energy demand in 2022, which goes up to 34 percent when adding energy used to produce materials used in the construction of buildings. The building and construction sector uses 35 per cent overall electricity produced across the globe which was 30 per cent in 2010.
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The International Energy Agency recorded one per cent rise in energy use in buildings because of added floorspace in emerging economies and increase in space cooling demand. The agency also noted the decrease in space heating energy demand due to mild winter in several regions. The demand for spacing heating is declining due to energy efficiency improvements but the demand for cooling continues to grow. The Sustainable Energy for All suggests that the fulfilment of this demand requires use of sustainable cooling strategies, development of passive cooling designs of buildings and cities, use of renewable energy sources and improving improving cooling performance through more efficient fabrics and equipment.
The International Energy Agency increase in air conditioners ownership from 37 per cent today to 45 per cent in 2030 due to space heating which is responsible for 33 per cent of total global final energy demand and 45 per cent space cooling service demand. The increase in the demand for cooling was largely driven by improvements in living standards increased floor area and higher temperatures. This increase is also due to the neglect of cooling-oriented envelope solutions and application of energy building codes. Due to these factors the air-conditioner ownership is expected to increase from 37 per cent of the global population today to over 45 per cent in 2030.
The Paris Agreement sets the target to reduce the energy consumption in buildings by around 25 per cent and fossil fuel use by more than 40 per cent by 2030. Achieving these targets requires replacing fossil fuels and traditional biomass with the renewables. Renewables 2023 Global Status Report indicates an increase in renewable energy use in buildings, which has grown by more than 50 per cent and now comprises around six per cent of total energy use in buildings. Brazil, Canada, France, Italy and Germany lead in renewables adoption in buildings, where as India, Russian Federation and the Republic of Korea are lagging. There is a need to increase production of renewable energy systems in order to reduce costs for widespread adoption, particularly in emerging economies where such systems can be unaffordable to many building owners.
Building Codes
The International Energy Agency expects around 80 per cent of projected floor area growth by 2030 will occur in developing and emerging economies and most of these countries lack the necessary building energy codes to achieve a whole-life net zero CO2 emission performance. Though the number of adopted codes globally are growing, there are still regions like Africa and parts of South America and Southeast Asia that will benefit from developing and adopting more modern codes because these are the regions where codes are yet to be developed, remain voluntary or are limited in scope and stringency. The modern building codes will promote advanced designs, envelopes and technologies that ensure buildings operate with the least amount of energy required to maintain comfortable and productive spaces. Additionally, codes must promote designs that capitalize on natural ventilation where the climate allows, as well as on day lighting and shading techniques to curtail energy demand while ensuring occupant comfort.
Building Construction Methods
The UNEP's report further states that the advent of global warming and extreme weather conditions like storms, floods and wildfires, adaptation and resilience in the built environment will become increasingly important. These climate events can manifest in risks that affect both building operations and maintenance. This will result in to increasing risk of overheating as global temperatures continue to rise throughout the 21st century, especially in higher density buildings (e.g. high-rise), buildings with low ventilation rates. Increasing prevalence of high wind and storms in many regions will also necessitate increased rates of repair and the need to improve building materials and methods to withstand such events.
Buildings with poor insulation, suboptimal orientation and insufficient ventilation may succumb to overheating during heat waves, amplifying health risks and escalating energy demands for cooling resulting in increasing greenhouse gas (GHG) emissions. Inappropriately designed structures may also rely heavily on energy-intensive air conditioning systems, exacerbating carbon emissions from regions without decarbonised electricity grids. Glass-dominated facades without solar control properties in many modern urban architectures can lead to excessive solar heat gain Says the UNEP's report .
The report further emphasises on passive design measures which includes well-designed water-sensitive green roofs, energy efficient materials and strategic design that incorporates solar shading and natural ventilation. This will also address the problem of ‘cooling poverty’ – the condition where marginalised communities are forced to make use of inefficient and often dangerous methods appliances to keep cool.
Williams Eynon suggests Resilient Retrofits for existing buildings to maximise resilience in the face of increasing environmental hazards. This include structural hardening, which protects against damage in the event of increased weather stressors and flood risk; second, resource conservation measures aimed at reducing the amount of energy a building needs – this can be achieved through installing solar shading, natural ventilation and night-vent cooling, green roofs, or by improving insulation and finally improving building energy supply resilience such as local renewable energy generation and storage measures.
Judicious Use of Water in Buildings
The sustainable building design and construction is required to minimise the impact of heating and cooling, reduce energy consumption and live a comfortable life. Along with the sustainable buildings design and construction we need to give attention to escalating global water crisis. As per Water Research Foundation 2023 global water use, storage and distribution estimated to contribute 10 per cent of global GHG emissions and the buildings and construction being responsible for around 15 per cent of freshwater use hence it is imperative to evaluate the role of the built environment in solving the water crisis. The global water crisis consists of major challenges:
The built environment provides the shelter to societies and economic development but does not give attention to the issues of water protection and preservation practices. The sector has the larger impact on water sector as follows:
The UNEPs Global Status Report on Bullrings and Construction suggested the following principles of water management, i.e. Prevent, Measure, Reduce, Reuse and Restore by which the buildings sector can address the global water crisis alongside the efforts to decarbonisation of buildings.