Decarbonising buildings and energy to cut urban emissions
Urban areas are responsible for approximately 75% of global primary energy consumption and 50-60% of global greenhouse gas emissions.[1] Much of this comes from the burning of fossil fuels for heating, cooling, and powering buildings. Meanwhile, the construction sector contributes an additional 23% of global emissions and is responsible for 30% of global resource consumption.
Cities need to build 35 million affordable homes annually until 2030 to meet housing needs globally. Every one of these new buildings is a chance to build clean, efficient, and affordable buildings from the start.
Additionally, with two-thirds of current buildings still standing by 2050 and less than 1%[2][3] being retrofitted annually, cities have a massive opportunity ahead of them. Scaling up retrofits can cut emissions, lower energy bills, improve air quality, and create thousands of good green jobs.
How cities are decarbonising energy systems and built environments
Mayors across C40 cities are taking action. They are updating building codes, setting building energy performance standards, phasing out fossil fuels in buildings, and switching to clean energy. Cities are also using cleaner construction practices. These measures cut emissions and energy bills while improving indoor air quality and comfort and creating good green jobs. City leadership is critical to the future of decarbonised, resilient, and equitable energy systems and built environments. C40 helps cities adopt effective strategies to tackle energy poverty, enhance energy efficiency, and switch to cleaner construction materials and methods while creating good green jobs. We provide tested frameworks, peer networks, and technical support to help cities innovate, test, and scale solutions.
Creating decarbonisation solutions that deliver for all residents
Cities understand that effective decarbonisation strategies for energy and the built environment require solutions that ensure affordability, equity, health, comfort, and economic viability. Successful strategies must:
Phase out fossil fuels in buildings and energy supply
The climate crisis is a fossil fuel crisis. Pollution from fossil fuels used in homes also causes significant health issues, including one in eight asthma cases in children[4]. Cities are implementing policies to decarbonise their energy grids, accelerate the uptake of renewable energy, and phase out fossil gas and solid fuels in buildings. They are also improving energy access and affordability for all residents.
Prioritise renovating and retrofitting over demolition
Renovating existing buildings instead of demolishing and rebuilding can cut emissions by 35%[5] and costs by 45%[6]. Since two-thirds of buildings that exist today will still be standing in 2050, cities are decarbonising existing buildings while creating healthier, more comfortable indoor environments for all residents:
- requiring existing buildings to meet energy performance standards
- replacing fossil fuel heating, cooling, and cooking equipment with electric systems
- retrofitting building envelopes to improve efficiency
- ensuring renovations use low-carbon materials and methods
Build healthier, more resilient, low-carbon buildings and infrastructure
The decisions cities make before construction begins have the greatest impact on a building or infrastructure project’s lifetime emissions. Material choices, construction processes, design, and equipment selection all determine the emissions profile of buildings and infrastructure over their lifespan.
Cities are ensuring new buildings, infrastructure projects, renovations, and maintenance work reduce both embodied emissions and energy use from day one:
- creating and updating building codes with stricter standards
- requiring life cycle assessments for major projects
- mandating low-carbon materials, energy sources, and equipment in municipal procurement
- establishing embodied emissions targets and building energy performance standards
- demanding zero-emission construction sites
These measures address emissions from construction (such as materials, processes, and sites) and ongoing building operations (such as heating, cooling, and power).
Create good green jobs through a just transition
Decarbonising buildings, energy, and construction is a massive opportunity for the creation of good green jobs in cities. Investment in decarbonising buildings could generate six times more good green jobs than fossil fuel investment. Cities are ensuring workers in energy, construction, and building management sectors have access to training and resources to make the most of emerging opportunities in building retrofit, clean energy installation, and sustainable construction practices.
Cities are demonstrating that this comprehensive approach works. Expanding renewable energy, reducing building emissions, and using cleaner construction practices create good green jobs and healthier living environments for all.
Connect with energy and buildings programmes and networks
C40’s work on energy and buildings provides different entry points for cities to implement decarbonisation strategies, access technical support, and learn from peers delivering similar solutions.
New Building Decarbonisation Network
Connect with cities implementing policies to ensure new buildings operate at net zero carbon while advancing equity, resilience, and public health objectives.
Private Building Decarbonisation Network
Access support to develop and implement policies that decarbonise existing, privately-owned buildings at scale.
Municipal Building Decarbonisation Network
Get guidance on decarbonising municipal building portfolios to demonstrate leadership, test new solutions, and build local market capacity.
Clean Energy Network
Join cities accelerating the renewable energy transition, enabling energy access, and maximising local renewable energy generation.
Clean Construction Forum
Connect with cities reducing embodied emissions and transitioning to cleaner construction practices for buildings and infrastructure.
C40 Net Zero Carbon Buildings Accelerator
Access a best-practice framework and case studies from cities committed to decarbonising operational emissions from buildings, ensuring that new buildings operate at net zero carbon by 2030, and all buildings by 2050.
C40 Clean Construction Accelerator
Join cities committed to creating the resilient, equitable, and decarbonised built environments of the future with the aim to bring together and inspire stakeholders to meet the collective goal of reducing emissions by 50% for new buildings and infrastructure by 2030.
Frequently asked questions
How can cities decarbonise energy and the built environment without increasing costs?
It is a misconception that clean energy and construction practices cost more than business-as-usual alternatives. Cities around the world are demonstrating that policies for grid decarbonisation, building energy efficiency, and clean construction can deliver healthier, more resilient homes, often at a roughly equivalent cost to business as usual. Switching to clean energy and implementing energy efficiency retrofits typically reduces energy bills for residents. Cities can ensure an equitable approach by providing subsidies for low-income households and frontline communities to help offset upfront costs. Clean construction practices, especially those that prioritise reuse of existing infrastructure and materials, can often be delivered at a fraction of the cost of building new.
What support exists for workers transitioning from fossil fuel industries?
Cities are partnering with workers, unions, and education and training institutions to provide reskilling opportunities in emerging green industries. This includes training in fields such as building retrofit, renewable energy installation, and clean construction. Investment in building decarbonisation generates six times more jobs than fossil fuel investment, and cities are committed to creating inclusive pathways for workers in traditional energy and construction sectors to make the most of these new opportunities.
What policies are most effective for phasing out fossil fuels in the energy and built environment sectors?
Effective policies include mandatory energy performance standards for new and existing buildings, requirements that new buildings connect to clean energy sources, bans on new fossil gas connections in buildings, planning for fossil gas phase-out at the neighbourhood scale, and clean energy installation and procurement targets to support grid decarbonisation. C40’s policy explorers showcase examples from cities implementing these and other approaches.
Resources
Related
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Cities are delivering climate action that creates employment, improves health, and addresses inequality rather than leaving people behind.
Sources
- [1] https://unhabitat.org/topic/urban-energy#:%7E:text=To%20run%20their%20activities%2C%20cities,the%20world’s%20total%20greenhouse%20gases
- [2] https://www.iea.org/reports/sustainable-recovery/buildings
- [3] https://www.iea.org/reports/energy-technology-perspectives-2020
- [4] https://www.theguardian.com/environment/2023/jan/06/us-kids-asthma-gas-stove-pollution#:~:text=A%20new%20study%20has%20now,the%20use%20of%20gas%20stoves.
- [5] https://www.ramboll.com/insights/decarbonise-for-net-zero/financial-benefits-of-building-renovation
- [6] https://bygherreforeningen.dk/renovering-giver-miljoemaessige-og-totaloekonomiske-fordele/