Global news
September 21, 2026
Ten ways for cities to solve the housing and climate crises
Cities do not have to choose between delivering more affordable homes and meeting their climate goals. In a new report launched at New York Climate Week, Ramboll and C40 Cities have identified ten proven approaches from Europe, Asia, and the Americas that help cities address both challenges in tandem.
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Signe Kongebro
Global Director, Future Resilient Design
Cities are under pressure to deliver more affordable and adequate housing for their residents. At the same time, they need to develop low-carbon urban infrastructure and prepare communities for a world increasingly affected by extreme climate events.
These priorities are often viewed as competing goals, with climate-related measures seen as adding cost and slowing housing delivery. But that does not need to be the case.
A new report from Ramboll and C40 Cities, “Where Housing Meets Climate: Practical ways to deliver affordable and climate-ready homes”, brings together ten proven approaches already being used by cities around the world, showing how housing and climate objectives can reinforce each other.
“A common misconception is that we have to choose between building enough homes and maintaining our climate ambitions, but that is a false choice. The report shows that many of the approaches cities are using today can help deliver both: homes in the right places, better use of existing buildings, lower household costs, and greater resilience to climate impacts.”
Senior Partner and Global Design Director for Urbanism, Ramboll
Where and how you build is as important as how much you build
The ten approaches outlined in the report span three scales of the urban environment: city, neighbourhood, and building level. They include measures such as densification, neighbourhood revitalisation, and building reuse and retrofit.
Based on these approaches, one of the report's central conclusions is that where and how cities build homes can be as important as how many homes they build.
The report calls for rethinking the use of existing land and buildings to meet local housing needs while mitigating climate impacts and improving the resilience of communities.
It also highlights the need for greater alignment between public and private capital, more effective use of public land and financial tools, and closer coordination between municipal housing, planning, transport, and climate departments, which could aid in a more just and sustainable buildout of housing infrastructure.
Get the key highlights below and sign up here to receive the full report.
“For too long, city leaders have faced pressure to scale back climate action under the persistent assumption that it will accelerate housing supply and drive down construction costs. This report shatters that dichotomy. From Bogotá to Warsaw, Vancouver to Jakarta, cities are already proving that affordability and sustainability can work in tandem. By prioritising solutions like transit-oriented development, infill solutions, tackling building vacancy, unlocking brownfield land, and innovative, cost-effective, low-carbon construction methods, we have the proven approaches to deliver affordable homes while reducing emissions and protecting our most vulnerable residents from escalating climate hazards.”
Senior Director of Climate Solutions and Networks and Director of Urban Planning and Design, C40 Cities
Three main takeaways of the report
- Fact:
1. Build more homes in the right places and address the “missing middle”
- Fact:
2. Breathe new life into existing buildings and neighbourhoods
- Fact:
3. Explore new public and private investment models
Infill and densification can make better use of vacant and underutilised land, while transit-oriented development can bring homes closer to jobs and amenities.
1. Build more homes in the right places and address the “missing middle”
Expanding cities outwards increases housing supply, but also consumes natural land, increases infrastructure costs, exposes new homes to climate hazards, and could make residents more dependent on cars.
Instead, cities should use planning and zoning to increase housing supply within existing urban areas, particularly around public transport and existing infrastructure.
The report highlights evidence that adding “missing-middle” housing such as duplexes, triplexes, and townhouses in established urban areas can reduce municipal infrastructure costs by up to 40% per unit1, lower household carbon footprints by over 20%2 , and improve affordability by sharing land and utility costs across smaller units.
2. Breathe new life into existing buildings and neighbourhoods
Cities do not have to build everything from scratch. Vacant homes, underutilised buildings, former industrial sites, and ageing housing stock all represent opportunities to create or improve homes while avoiding the emissions associated with new construction.
Deep retrofits can cut embodied carbon emissions while reducing household energy costs and improving resilience to heat and cold. Adaptive reuse can turn obsolete offices and other buildings into homes, while neighbourhood-scale regeneration can combine building upgrades with greener public spaces, better drainage, and more efficient energy systems.
In Brussels, for example, the BatEx programme has retrofitted residential blocks to Passive House standards, achieving energy savings of up to 80%. Seoul has combined a building energy database with interest-free retrofit loans to target low-income areas, which prompted 4,000 home upgrades3.
3. Explore new public and private investment models
The true cost of housing extends beyond rent or the purchase price. Energy, transport, insurance, and maintenance costs all affect whether a home is genuinely affordable. Likewise, a cheap home in a flood-prone area or a poorly insulated building can expose residents to much higher costs over its lifetime.
This means cities need to look beyond the upfront cost of construction and consider the full value created by housing. Doing this at large scale requires changes to how housing is financed and governed.
The report recommends that measures such as affordable housing requirements, tenant protections, and community land models are considered alongside physical investment from the outset.
Get the report
“Where Housing Meets Climate: Practical ways to deliver affordable and climate-ready homes” brings together ten approaches, international case studies and practical recommendations for city leaders, planners, developers, and housing organisations.
Download the report to explore the ten approaches and discover practical actions cities can take to deliver more affordable, climate-ready homes.
About the partners and the report
The report is developed as part of a strategic partnership between the Ramboll Foundation and C40 Cities aimed at accelerating urban resilience and putting community wellbeing at the heart of city development. The partnership brings together C40's global network of city leaders with Ramboll's research, advocacy and technical expertise to support cities in developing more resilient and sustainable urban environments.
The report was launched at the Partnerships for the Future Summit at Climate Week in New York on 21 September, with keynotes from the former mayor of Paris, Anne Hidalgo, and the Lord Mayor of Copenhagen, Sisse Marie Welling. The findings were presented and discussed by a panel of experts, including Heather T. Clark, former Senior Director for Building Sector Climate Policy at the White House under the Biden Administration; Thure Krarup, Global Public Affairs & Policy at Urban Partners; Signe Kongebro, Senior Partner and Global Design Director for Urbanism at Ramboll; and Hélène Chartier, Director of Urban Planning and Design at C40 Cities.
[1] Victoria Transport Policy Institute. Smart Growth Policy Reforms. 2023. https://vtpi.org/smart_growth_reforms.pdf
[2] EPA, and
[3] Copenhagen Centre on Energy Efficiency. Building Retrofit Program (BRP); Loan Support Scheme - Copenhagen Centre on Energy Efficiency
Want to know more?
Signe Kongebro
Global Director, Future Resilient Design
Paulina Lis
Senior Consultant
+45 51 61 34 92
Jonathan Martins
Senior Manager, Global Industry Lead Buildings & Cities
+45 51 61 00 82
