Forest, Ixelles and Saint-Gilles

Reducing waste through community gaze and social influence

Behavioural science Community engagement Waste management

The Challenge

Forest, Ixelles and Saint-Gilles wanted to reduce litter, cigarette butts, illegal dumping and dog mess. Traditional awareness campaigns and fines had limited impact. With a modest budget, they needed an approach that would deliver lasting behaviour change in public spaces.

Our Approach

We applied behavioural science to focus on the “community gaze” effect, signalling that the community is watching. Working closely with residents, cleaning staff and municipal teams, we co-designed localised communications to ensure authenticity and relevance. We then delivered targeted, context-specific messages at problem hotspots, each with tailored calls to action for different types of waste.

The Result

The project produced measurable reductions in waste and stronger community engagement. Cigarette litter dropped by 56% at Mont des Arts and 26% at Gare du Midi following the distribution of pocket ashtrays. Calls for bulky waste collection rose by up to 46%, showing higher use of legal disposal services. Municipalities are now equipped with an evidence-based model that is set to expand across Brussels.