More specifically, the selected proposals have the following features:

• Panot del s. XXI. A system for setting paving stones which enables practically all the stones to be reused during maintenance operations. In addition, a close-to 50% reduction in CO₂ gas emissions is achieved.
• PANOT+. This incorporates cement with less impact from CO₂ emissions.
• R3PANOT. This is the proposal that achieves the biggest reduction in CO₂ emissions, as much as 65%.

A pilot test for putting a roof over Eixample’s first green hubs

The three selected solutions will be tried out in public spaces in a pilot test towards the end of the year, in the framework of the Barcelona Superblock Plan and the reurbanisation of Eixample’s first four green hubs. Each of the winning proposals, which will receive 80,000 euros, will devise the necessary prototypes for putting a roof over a surface area of 1,000 m² within the area of the new hubs, as well as the certification of the features of the paving stones produced.

After a year of monitoring to test out their functioning, their behaviour has been assessed to determine whether or not they will be authorised. The stone paving that ends up being developed with have an open licence in Barcelona.

The challenge of a paving stone for the 21^st century is being developed by the BIT Habitat municipal foundation, which is promoting urban innovation to meet the social, economic, technological and environmental challenges facing the city.