Energy Efficiency
Climate Change

Zero carbon cities: Insulating populations for a sustainable future

Susanne Dyrbøl
Susanne Dyrbøl
March 5, 2020

Cities are at the forefront when facing the direct impact of climate change, and we see more and more cities taking serious and tough actions to combat the effects at a local level

Green city scape

Every city has a unique identity. It is evident in the skylines, parks, quaint architecture, and their distinct transport systems. Built-up over hundreds (or sometimes thousands) of years, these urban centres support the majority of the world’s populations today. While a city’s evolving characteristics are indicators of steady progress, it has become just as important to display their sustainable strategies for the future. Cities like Copenhagen currently lead the way in this regard, encouraging inhabitants and tourists to make eco-friendlier decisions and help reduce the Danish capital’s carbon footprint.

Four years ago, almost 200 countries signed the Paris Agreement aiming to significantly reduce their greenhouse gas emissions. The goal was to reduce the average global temperature rise to well below 2 degrees Celsius. In 2018, the UN Intergovernmental Panel on Climate Change issued a special report highlighting the effects a 1.5 degree Celsius temperature rise would have on the environment. The findings indicated a far bigger impact than originally anticipated.

Cities are at the forefront when facing the direct impact of climate change, and we see more and more cities taking serious and tough actions to combat the effects at a local level. Across the world, city and national governments will need to look for innovative ways they can achieve their goals and reduce their carbon footprint. One area that shows the most potential for future sustainability is adopting and improving energy codes for new and existing buildings. It continues to be a concern that many developing economies still do not have mandatory energy codes for buildings despite high construction rates.

Updating building codes for a changing climate

In 2019 the Coalition for Urban Transitions reported that 10,000 cities around the world had made commitments to mitigate carbon by 2050. To assist cities with their initiatives, the coalition has developed a six-part action plan that serves as a roadmap towards clean cities with net-zero carbon emissions. Priority one is to place cities at the centre of the plan, while priority two focuses on aligning national and local policies for compact, connected, and clean cities.

The strategies contained in priority two of the Climate Emergency Urban Opportunity Report include:

  • Introducing net-zero carbon building codes for new buildings and achieving net-zero operating emissions in public buildings.
  • Removing national land-use policies and building regulations that prevent denser, mixed-use urban development.
  • Reforming energy markets to decarbonize electricity grids by 2050.
  • Reducing the sales of fossil-fuel-powered vehicles like motorcycles, passenger cars, and busses.
  • Adopting alternatives to steel and high-carbon cement by 2030.
  • Shifting away from building detached houses in established cities.

Of these six strategies, the one that stands out with the most potential is enforcing energy codes for buildings. As most of the world’s building stock remains centred in cities, expanding regulations towards ultra-low energy buildings is a commercially attractive way to improve carbon-efficiency.

High performing new constructions designed to operate on a very low energy demand currently do not form part of building codes in two-thirds of countries. In 2018, only sixty-nine countries had mandatory or voluntary energy codes for buildings on their books. Achieving the carbon-neutral goals of the future without these changes to building codes will not be possible.

The future needs sustainable buildings

As of 2018, 39 percent of the world’s carbon emissions originate from the construction and operation of buildings while they also consume 36 percent of final energy. Most of these structures exist in cities and the people who built them rarely considered the efficiency or the overall environmental impact during their design without legislation in place. To achieve the goals of the Paris Agreement, a 30 percent reduction of the global average energy intensity per square metre will be necessary by 2030. This would require almost doubling the current energy performance improvements to above 2 percent every year beyond  the next decade.

It is important to note that carbon and energy are different metrics but rely on the same strategies to improve efficiency. The reduction of emissions similarly equates to decreased energy consumption in buildings. Due to the slow adoption of mandatory energy codes  around the world, more than 3 billion square meters of new buildings in 2018 did not have energy efficiency as part of their design’s mandate.

To ensure buildings are part of the solution in the fight against climate change, this will need to change quickly. According to the IEA, high-performance new construction should increase from 250 million square meters per year to 4 billion. At the same time, the deep renovation of existing building stock for improved energy efficiency needs to double.

A holistic approach to improving buildings and urban quality of life

The strategic adoption of  energy codes for buildings is not a new idea. The National Building Institute works with governments (mainly in North America) to improve codes and policies to address energy use in buildings. Between 1992 and 2012, energy codes in the United States led to cumulative savings of 1200 terawatt-hours of primary energy and avoided 320 million metric tonnes of carbon dioxide emissions.

In carbon savings alone, that is more than what the entire country of France produced in 2017. The adverse effects of inefficient buildings do not just affect the environment. According to C40, half a million people die every year from outdoor air pollution derived from the energy used in buildings. Seizing the opportunity that the renovation and construction of energy-efficient buildings offer cities depends on the local governments taking action now.

Statistics for city and national governments to consider

Humans spend most of their time inside buildings. It is where people live, learn, work, and recover. The energy improvement rate in 2018 was the lowest in the last decade. If the governments and local officials are sincere about their commitments to the environment, they will need to enforce a sustainable development strategy that starts with ambitious energy efficiency regulation for the building sector.

The cities of the world resemble living organisms. The places where most humans live will need to evolve towards safer, more comfortable, and sustainable environments. Net-zero carbon buildings are green and healthy structures with excellent thermal efficiency, renewable energy sources, and insulation that shields humanity from the changing climate of the future. Implementing energy codes for buildings and plans for further development of the codes will enable innovation and encourage private sector leadership.

To reduce energy use and carbon emissions in the building sector, energy codes are one of the most effective tools available to governments and cities. Developing building codes for improved energy efficiency and reducing demand must be the first priority for policymakers today.

We help city and national governments solve complex issues with modern building materials that are sustainable and improves the safety and comfort of a building’s inhabitants. By harnessing the seven strengths of stone to refurbish the world’s cities, buildings can become resilient enough to withstand the climate challenges in the future.

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