Maker spaces and maker activities offering access to low-cost digital fabrication equipment are rapidly proliferating, evolving phenomena at the interface of lay and professional design. They also come in many varieties and change fast, presenting a difficult target for, for instance, public authorities, who would like to cater for them but operate in much slower planning cycles. As part of participatory planning of Helsinki Central Library, we experimented with a form of collaborative futuring with and by makers. By drawing elements from both lead-user workshops and participatory design,we conducted a futuring workshop, which allowed us to engage the local maker communities in identifying the issues relevant for a public maker space in 2020. It further engaged the participants in envisioning a smaller prototype maker space and invited them into realising its activities collaboratively. Our results indicate that particularly the information about future solutions was of high relevance, as was the opportunity to trial and elaborate activities on a rolling basis in the prototype space. Insights about more general trends in making were useful too, but to a lesser extent, and it is likely that these could have been gained just as easily with more traditional means for futuring.