Rethinking Roofs: A Call for Innovative Heat Solutions

Over 1.1 billion people live in informal settlements, often in highly deprived urban environments. In several countries, informal settlements house more than half of the urban population, and in a few cases, this share exceeds 90%. Given that the global supply of new housing rarely exceeds 7 units per 1,000 inhabitants per year, even highly committed governments would need generations to address the current affordable housing challenge.

Urban heat is increasingly studied in formal and informal settlements alike. Deprived areas are often several degrees hotter than their formal surroundings due to lack of vegetation, high density, and material choices.

Residents typically have the least resources to prevent or mitigate heat exposure, a stark example of climate injustice. Heat can have profound impacts on health, education, livelihoods, and overall well-being.

At first glance, roof construction seems straightforward. The most commonly used material is corrugated metal, valued for its lightweight, durability, availability, and low cost. However, these advantages come with a major drawback: metal heats up quickly, leading to excessively high indoor temperatures.

Recognizing this challenge, we invite the international community of creative minds—students, designers, researchers, slum dwellers, and practitioners—to envision a world where hundreds of millions of people can live in cooler, safer homes.

 

What alternatives exist to current roofing methods that can ensure resilient, affordable, and thermally comfortable roofs in informal settlements?

 

How can roofs in informal settlements be built to be resilient, affordable, and cooler/ reducing indoor heat stress?

Scope of Solutions

 

Solutions can be new or traditional, high-tech or low-tech, social or technical, implemented or at the idea stage. To encourage diversity of ideas, submissions are welcomed in two categories:

  1. Physical Solutions: Focused on the roof as a material and structural object.
  2. Collective / Social Solutions: Focused on community-driven, organizational, or participatory approaches to roofing challenges.

Both innovative ideas and already implemented solutions are encouraged.

The challenge of heat in informal settlements is much broader and require discussion on housing unit, neighbourhood and even broader levels. However, a focused lens on materiality (and its technical and social dimension) can refocus ongoing discussions and provide a lens to unfold the complexity of informality, deprivation, and the built environment.

Submission Modality

The competition will take place in two phases.

Phase 1 – Open Call:

This first phase invites any creative mind—whether you are a student, resident of an informal settlement, member of a grassroots organization, designer, researcher, or practitioner—to share your innovative idea or describe an already implemented solution. The call aims to gather a wide range of perspectives, from local ingenuity to professional expertise.

Possible Submission Formats:

Participants are free to choose the format that best represents their idea or project:

  • Video or audio submission (max. 3 minutes) – clearly explaining the solution, how it works, and why it is effective.
  • Graphical or text-based document (max. 3 pages) – using visuals, sketches, photos, or written explanations. (As a reference, one page corresponds roughly to letter/A4 size.)

Phase 2 – detailed entries by shortlisted participants

Timeline

Date                                                                       Milestone

December 1, 2025                                         Call for submissions opens

January 21, 2026                                            Submission deadline (Phase 1)

February 1, 2026                                            Communication of shortlisted submissions

March 1, 2026                                                  Submission deadline (Phase 2 – detailed                                                                                                                           entries by shortlisted participants)

March 15, 2026                                              Announcement of winners

Prizes and Recognition

Prizes:

  • Top 3 winners in each category: Can showcase their solutions internationally through technical drawings, photos, or video messages.

 

  • Winner of each category: Will be invited to present their work in a dedicated session at the World Urban Forum*.

 

  • All winners: Will have the opportunity to test their innovative solutions in a real-life informal settlement

 

*Subject to external funding (if funding allows), travel and accommodation costs for up to two representatives per winning project will be covered by the organizers.

Share Your Story: Living with Heat in Informal Settlements

No ideas for solving one of the biggest construction problems in the world? No problem — you can still be a part of it!

We want to hear from residents, students, creators, and anyone with a story to tell.
How do you experience heat in your home or community? How do you cope with rising temperatures? What creative ways have you and your neighbors found to stay cool?

Your contribution is not part of a competition. It is a space to share, inspire, and connect.
Your story will help the world understand daily life in informal settlements and celebrate local creativity and resilience.

 

Join us and share your story, click below fill in the form and send it with the audio to: info@inform2build.net