Growfunding is a reward-based/civic crowdfunding platform based in Brussels. Starting in 2013 as research project at the “social work and community development”-department of the HUBrussel (now Odisee University-College). Growfunding was launched in 2016 as a spin-off and operates as the only non-profit crowdfunding platform in Belgium. Over the past years, more than 41.000 unique growfunders (i.e. someone who donated to at least one project) funded over 500 social impact projects in Belgium for a total amount of over 4.200.000 €. Thanks to the participatory rewards, about 87.000 people were directly involved in bottom-up urban projects. Our social impact methodology focuses on creating and enforcing new forms of urban solidarity and citizenship, with crowd building, crowdfunding and crowdsourcing as social network tools.