On Tuesday 18th November I participated in a debate organised by the Centro de Innovación y Tecnología para Desarrollo Humano at MediaLab-Prado on the topic, How can citizen laboratories and maker culture contribute to sustainable development? Medi-Lab Prado is an impressive space with a range of resources and technologies for citizens to come and develop their projects in teams, including a new FabLab, and so an appropriate place for the debate. But the debate was only a stopping off point on a tour of grassroots innovation spaces in Madrid, and which had begun with a visit to Esta es una plaza, and which concluded after the debate at Makespace Madrid. So, can the contribute to sustainability? In the debate (in Spanish) I argued it was the social relationships built within the spaces and between the spaces and their communities that would determine whether and how they might contribute, rather than the technologies that are so visible on the surface.