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 1st, 2025                                   Call for submissions opens

January 25th, 2026                                     Submission deadline (Phase 1)

March 11th, 2026                                        Communication of shortlisted submissions

April 15th, 2026                                            Submission deadline (Phase 2 – detailed                                                                                                               entries by shortlisted participants)

May 15th, 2026                                            Announcement of winners

May 17th to 22nd, 2026                          Exhibition at WUF13, Baku

Prizes and Recognition

  • World Urban Forum: Best entries will be showcased at the Habitat Village on Thursday, 21 March. While hybrid sessions aren’t possible, participants may send a 3–5 min video/presentation (optional).
  • Implementation: ROOH (Roofs Over Our Heads) will support the rollout of the most advanced proposals in one of their “labs” (informal settlement).
  • Knowledge Series: Starting September 2026, winners of both categories will present their work in an online session, followed by two targeted webinars.
  • Publication: A book will document all projects, with the top four winners per category featured in detail.
  • Conference: Planned in the Netherlands (Oct/Nov 2026). Project Leaders of the 1st and 2nd place winners will be invited to present. An SDI builder will construct an informal housing unit featuring the winning roofing solution

 

Rethinking Roofs Global Competition

Technical Solution

Winner

Second place 

3rd Place 

Collective/ Social Solution

Winner

2nd Place

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