During 2009 and 2010 a participatory process was organised, the A+S Convention, which involved more than 300 employees, from all levels, different departments and independent organisations. This was a clear example of empowerment. Not only was it an informative process but the participants, accepting their co-responsibility, also defined by consensus the goals of the Programme for the 2012-2020 period, which are contained in the document A + Sustainable City Council Programme, Future Commitments.

The objectives of the convention were to review the actions taken during the last ten years, agree on future goals and actions to be undertaken, promote the involvement and complicity of the entire institution in the A+S Programme, and give the programme a central and visible role in municipal institutions.

The work was carried out by five specialised working groups made up of city council staff expert in each field:

• Construction, public works and building refurbishment.
• Savings on and greater efficiency in the use of environmental resources in public buildings.
• Coordination of the A+S Plan with other municipal programmes and initiatives.
• The social side of a + Sustainable City Council.
• The + Sustainable City Council day by day.

On 18 March 2010 the closing act of the A+S Convention took place. It was an institutional event, chaired by the mayor of Barcelona and the deputy mayor, councillor for the Environment. It was attended by 271 members of the council staff, including the municipal manager and leading administrators from various departments and districts.

One of the most important results of the participatory process, also open to all council staff through an online platform, was the definition by consensus of the strategic objectives and the lines of action of the A+S Programme.

The A+S Convention was itself an example of greening, and during the closing act awards were given for the most outstanding internal initiatives and projects aimed at the incorporation of sustainability criteria.