Building resilient cities
Explore the challenges facing cities and the sustainable solutions helping them prepare for the future
We expect nearly 70% of the world population to be living in cities by 2050, adding 2.5 billion people.
The race is on for cities to adapt to a rapidly changing climate. They must be resilient to increasingly frequent severe climate events while prioritizing sustainability, durability and quality of life for generations to come.
As a global leader in innovative and sustainable building solutions, Holcim is ready to be the key partner to cities on this journey. We have identified five built environment challenges faced by city mayors today. We are putting our solutions to work in these areas to make the cities of tomorrow more climate resilient, circular and energy-efficient, with more nature inside.
5 challenges for cities
1. Reduce CO2 emissions in the built environment
Since buildings account for 37% of the world’s CO2 emissions, decarbonizing building is essential for a net-zero future.
Low-carbon building solutions help cities curb greenhouse gas emissions and enable a lower carbon footprint. By empowering smart design and deploying new building technologies, we can use minimum materials for maximum strength.
About 60% of buildings that will exist by 2050 haven’t been built yet, so new construction must be sustainable.
2. Accelerate circularity in construction
Construction materials and the building sector are responsible for almost a third of global resource consumption. By 2025, construction demolition materials are expected to account for 2.2 billion tons of waste globally each year.
Cities are at the forefront of making circular construction the norm to respect planetary boundaries and improve living standards for all. This means reusing construction demolition materials to build new from old and close the material loop.
With the global economy being just 7.2% circular, we are set to consume over two planets by 2040.
3. Increase buildings' energy efficiency
Roughly 75% of all global energy consumption occurs in cities.
Buildings present a unique opportunity to speed up the transition to decarbonized energy and highly energy-efficient cities. Roofing, insulation and green retrofitting have an important role to play in making buildings more sustainable in use to decarbonize cities.
Energy used to power, heat and cool buildings causes up to 80% of CO2 emissions in cities.
4. Improve resilience to climate events
Cities are at the forefront of a rapidly changing climate, from rising sea levels and flooding to severe temperatures.
Adaptation work helps cities take action to protect residents and infrastructure from immediate and future climate risks, as well as to develop solutions and implement actions towards transformational, city-wide resilience to the impacts of climate change.
650 million people will face water scarcity and 1.6 billion people will face extreme heat in 2050.
5. Boost biodiversity
A positive natural future for the “urban century” necessitates sustainable urban growth that occurs in appropriate places while nearby nature is protected, restored and enhanced.
Nature in and near cities is crucial not just for maintaining biodiversity but for ensuring human wellbeing, which depends on the benefits that nature provides. These benefits include serving as a major carbon sink, with land and oceans absorbing more than half of all greenhouse gas emissions.
Around 290,000 km2 of natural habitat is likely to be lost to urban expansion between 2000 and 2030 – almost equivalent to the size of Italy.
Reduce CO2 emissions in the built environment
Since buildings account for 37% of the world’s CO2 emissions, decarbonizing building is essential for a net-zero future.
Low-carbon building solutions help cities curb greenhouse gas emissions and enable a lower carbon footprint. By empowering smart design and deploying new building technologies, we can use minimum materials for maximum strength.
About 60% of buildings that will exist by 2050 haven’t been built yet.
Accelerate circularity in construction
Construction materials and the building sector are responsible for almost a third of global resource consumption. By 2025, construction demolition materials are expected to account for 2.2 billion tons of waste globally each year.
Cities are at the forefront of making circular construction the norm to respect planetary boundaries and improve living standards for all. This means reusing construction demolition materials to build new from old and close the material loop.
With the global economy being just 7.2% circular, we are set to consume over two planets by 2040.
Increase buildings' energy efficiency
Roughly 75% of all global energy consumption occurs in cities.
Buildings present a unique opportunity to speed up the transition to decarbonized energy and highly energy-efficient cities. Roofing, insulation and green retrofitting have an important role to play in making buildings more sustainable in use to decarbonize cities.
Energy used to power, heat and cool buildings causes up to 80% of CO2 emissions in cities.
Improve resilience to climate events
Cities are at the forefront of a rapidly changing climate, from rising sea levels and flooding to severe temperatures.
Adaptation work helps cities take action to protect residents and infrastructure from immediate and future climate risks, as well as to develop solutions and implement actions towards transformational, city-wide resilience to the impacts of climate change.
650 million people will face water scarcity and 1.6 billion people will face extreme heat in 2050.
Boost biodiversity
A positive natural future for the “urban century” necessitates sustainable urban growth that occurs in appropriate places while nearby nature is protected, restored and enhanced.
Nature in and near cities is crucial not just for maintaining biodiversity but for ensuring human wellbeing, which depends on the benefits that nature provides. These benefits include serving as a major carbon sink, with land and oceans absorbing more than half of all greenhouse gas emissions.
Around 290,000 km2 of natural habitat is likely to be lost to urban expansion between 2000 and 2030 – almost equivalent to the size of Italy.
What does a resilient city look like?
To tackle these five challenges, cities need a range of solutions to build more sustainably and retrofit existing buildings and infrastructure.
At Holcim, we are collaborating with city mayors, architects, authorities and urban planners around the world to make our cities more resilient.
Take a tour of a resilient city and see our solutions in action.
A resilient city is designed to be sustainable, durable, circular, nature-friendly and to withstand severe climate events.
Building low-carbon
This starts with decarbonizing construction at a city-wide level – housing, schools, hospitals, infrastructure. Low-carbon building solutions enable us to reduce buildings' carbon footprint and curb greenhouse gas emissions.
We offer the world’s broadest ranges of low-carbon concrete with ECOPact and low-carbon cement with ECOPlanet. They deliver 100% performance with at least 30% less CO2, in line with the most advanced sustainability certifications, from LEED and BREEAM to WELL.
Maximizing durability
To withstand extreme weather conditions, buildings and infrastructure must be designed in a way that is durable.
DYNAMax high performance concrete delivers high strength, outstanding durability and superior rigidity to optimize usable space and build longer-lasting buildings. DYNAMax requires less materials than conventional building solutions, enabling us to build better with less and reduce CO2 emissions in construction.
Recycling construction demolition materials into new building solutions
To make construction circular, we need to shift to a “reduce, recycle, regenerate” economy where materials stay in use for as long as possible.
ECOCycle®, our proprietary circular technology platform, recycles construction demolition materials into new building solutions. For example, to build transport infrastructure, we can take materials resulting from the excavation of underground stations to replace the aggregates necessary for concrete production.
All products with ECOCycle® inside – cement, concrete or aggregates – contain from 10% to 100% recycled construction demolition materials.
Building better with less using smart design
By leveraging smart design, we can optimize material use without compromising on performance.
Carbon pre-stressed concrete (CPC) slabs are thin, light precast plates made of high-strength concrete reinforced with prestressed carbon fibers, which have the same load-bearing capacity as standard concrete slabs. They use up to 80% less material with up to 75% lower CO2 emissions, and are circular by design.
Designing for efficient heating and cooling
The need to transition to renewable energy sources and rising costs for heating and cooling buildings means that the places where we live, learn and work must be designed to be as energy-efficient as possible.
Building energy-efficient cities starts at the design stage. Thermal concrete activation (TCA) is one of the most effective solutions to achieve energy storage. Concrete is excellent at storing and conducting heat, so concrete load-bearing components can play the role of energy storage units if they are designed accordingly. Combined with low-carbon concrete such as ECOPact, this solution can precharge buildings with energy that can be stored and released for heating and cooling as needed in an even more sustainable way.
Shifting to decarbonized sources of energy
Holcim’s solutions are enabling the energy transition.
ECOPact low-carbon concrete is making the construction of wind farms more sustainable. It delivers 100% performance offering at least 30% lower CO2 emissions compared to standard (CEM I) concrete, helping reduce the carbon footprint of renewable energy infrastructure.
One prerequisite for installing solar panels is having a roof that can last as long as they can. Elevate EPDM Roofing Membrane systems have a lifespan of over 50 years, allowing rooftop renewable energy systems to maximize their use life.
Making buildings energy efficient with advanced roofing and insulation
Roofs account for up to 60% of a building’s energy loss. Both for new builds and existing buildings, insulation plays an instrumental role in making buildings sustainable.
Holcim’s Elevate ISOGARD boards provide the highest thermal insulation in the US market – up to 40% above standard competing solutions – making buildings more energy-efficient and cost-effective in use.
Made of up to 95% air, Airium™ is an extremely lightweight mineral-based insulating foam. For both new builds and green retrofitting, Airium™ can be used in roofs, walls, floors and terraces, as well as inside concrete blocks.
As a cool roof system, Duro-Last’s Bright White Membrane reflects up to 88% of the sun’s energy. This ENERGY STAR qualified membrane also releases energy and heat efficiently, greatly reducing energy costs.
Strengthening coastal resilience
By 2025, 410 million people in coastal communities could be at risk of coastal flooding and sea-level rise.
Holcim offers innovative solutions for coastal engineering, river protection and infrastructure construction. Basalton is the concrete version of natural stone basalt – a shore protection system for coast and revetment areas providing stabilization and erosion control.
Improving water management and protection
Water-related disasters – heavy rains, river floods, storm surges, inland flooding and flash flooding – are the most destructive of all natural disasters.
Holcim offers a wide range of innovative solutions to avoid flooding and improve cities’ water management capacity. Hydromedia permeable concrete is a water management system that rapidly absorbs rainwater off streets, parking surfaces, driveways and walkways – reducing the risk of flooding. It enables the ultra-rapid evacuation of water directly into the soil, producing a natural aquifer recharge or allowing the water to be recycled.
Our precast stormwater management solutions include drainage, detention, treatment, harvesting and reuse systems, such as the Universal Pollutant Trap (UPT).
Reducing air pollution
Air pollution is a global challenge, and urban environments often suffer the most.
Malarkey launched the world’s first smog-reducing shingle that removes smog gases from the air in the same way that trees do, by using sunlight. An average-sized Malarkey residential roof improves air quality to a similar extent as planting two new trees.
Making cities cooler by reducing the urban heat island effect
The urban heat island effect makes cities warmer than the surrounding rural area, putting urban dwellers at high risk of various heat stress conditions.
Communities can create urban forests and green spaces to reduce the effects of heatwaves in cities. Trees and other plants cool the surrounding environment by offering shade and releasing water through their leaves.
Our range of innovative solutions can help cities reduce these risks. With its permeability properties, Hydromedia permeable concrete allows direct rainwater infiltration over urban surfaces, meaning we can create an urban forest environment without the need for irrigation.
"Buildings are a game changer for climate solutions. At Holcim, we want to be part of supporting and enabling cities to build in a way that is low-carbon, circular, energy-efficient and with more nature inside."
Holcim's solutions in action
In Greece, Holcim's ECOPact low-carbon concrete is being used for the largest urban regeneration project in Europe: the Ellinikon, located outside of Athens. By using ECOPact, the Ellinikon development will be able to reduce the carbon footprint of concrete in its buildings and infrastructure by at least 30%.
Holcim’s Elevate insulation solutions helped the Winthrop Center in Boston, USA, become the world’s largest Passive House-certified office building. Elevate's ISOGARD formulation delivers up to 40% better thermal performance than other products on the market and the building is expected to use 65% less energy than the average Boston office building.
In Dubai, United Arab Emirates, we are aiding the construction of the Al Wasl Tower with Airium™ insulation. Made of up to 95% air, our fully recyclable Airium mineral insulating foam will play a key role in increasing energy efficiency – all the more important in a region known for its hot days and cool nights.
Thammasat University in Bangkok, Thailand, is home to the largest urban rooftop in Asia. The 22,000-square-meter Elevate green roof is enabled by UltraPly TPO thermoplastic membrane – a durable waterproofing solution which offers excellent weathering performance and ability to withstand extreme temperature conditions.
For the Cosmopolitan Skyline tower in central Tijuana, Mexico, the developer chose DYNAMax ultimate performance concrete. This solution helps complex projects such as this one to reduce material use by up to 50% during the construction process, and ensures high resistance, maximum durability and rigidity.
In Austria, Holcim’s low-carbon cement contributed to sustainably building one of the most energy-efficient schools in Vienna, the Bildungscampus Seestadt. Using a geothermal energy process optimized by thermal concrete activation (TCA), the school is able to cover 90% of its own energy needs.
In Montana, USA, Malarkey Roofing Products enabled the climate-resilient, durable and circular renovation of a residential roof. Malarkey’s Legacy® roofing shingles are made with recycled materials, including rubber tires and plastic bags, and are capable of withstanding extreme climates. The product was awarded top honors in the 2024 Excellence in Asphalt Roofing Awards.
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