AT speaks to Dani Alsina, Director of Innovation at BIMSA, about why they are challenging international practitioners to design a new method for material reuse in the wake of the 2026 International Union of Architects Congress.
What issues are Barcelona’s public spaces currently facing in terms of waste material management?
Every year, thousands of square metres of streets and squares are regenerated in Barcelona. These works generate millions of tonnes of Construction and Demolition Waste (CDW). All CDW goes to a plant where up to 70% is converted to recycled aggregates and the rest is sent to landfill.
What is the “MINERAL. Architects of Urban Mining” Challenge and how will it tackle this issue?
Barcelona has been designated by UNESCO as the World Capital of Architecture 2026. In the summer of 2026, the city will host the International Union of Architects (UIA) Congress, three decades after hosting its 19th edition in 1996.
As part of this initiative, in 2025, the city will launch the urban challenge “MINERAL. Architectures of Urban Mining,” an innovation grant program with a total funding of €336,000. This challenge is a collaborative effort between the Barcelona City Council, Barcelona d’Infraestructures Municipals (BIMSA), BIT Habitat Foundation, Mies Van der Rohe Foundation, the Barcelona Provincial Council,and the UIA, aiming to develop innovative solutions and processes for reusing residual materials from urban construction works. The goal is to create a new architectural system or construction method to recover and reuse the excessive amounts of CDW produced in Barcelona. These new concepts should be applied preferably to regeneration projects in public spaces, but the jury will consider more general building works as well.
What are you looking for in successful proposals?
We are searching for innovative proposals but they must also be feasible, scalable, and replicable since our ultimate goal is to design a new sustainable method for all cities to use. Hence we are not simply looking for a new material but would like to go one step further. We are searching for a new architectural philosophy, a new construction concept and a new system of reuse with architectural values at its core. Whilst we are looking for an architecturally minded response, the challenge is not limited to architecture practices. We are also inviting submissions from engineering firms, universities, foundations. A full list can be found once the challenge is launched in late march.
What waste materials can be used in the design of the new system?
The ones found in our streets and squares are mostly asphalt, concrete, recycled aggregates, soil and granite, and sometimes a mixture of all of them. We suggest considering new ways to recover these materials from the existing street so they are in a better condition to be reused.
What is the timeline for competition entries?
All information such as specific dates and what is expected through each phase of submissions will be released on the BIT Habitat website around the 24th March.
Will any financial support be offered to the successful entries?
A €6000 prize will be awarded to shortlisted proposals from the first phase of submissions, who will then advance onto phase two. A maximum of €150,000 will be awarded to the two winning projects.
2026 is an exciting year with Barcelona hosting the International Union of Architects Congress. How is the competition linked to this major international event?
The 2 winning proposals will showcase prototypes of their solutions at the Barcelona UIA Congress 2026 exhibition and will participate in lectures and debates. They will also be partnered up with a manufacturer of their choice who will help their solutions become feasible and replicable, presenting opportunities to market and manufacture the solution on a wider scale.
Dani Alsina
Director of Innovation, "Barcelona d'Infraestructures Municipals" (BIMSA)
