"Development decision-makers increasingly recognise community-based adaptation (CBA) as a viable way to build communities’ resilience to climate change, particularly those most vulnerable to its impacts. CBA puts them in the driving seat when it comes to designing and delivering adaptation options. However, until recently, analysis of the impacts beyond the immediate beneficiaries was not possible because not enough CBA projects had been implemented. As a result, most of the lessons about best practice have yet to be scaled out or included in wider development policies. This Working Paper explains the initial thinking from the Climate and Development Knowledge Network (CDKN) on how to increase the scale and impact of CBA. It draws upon CDKN’s experience and learning, and that of our partners, from a diverse range of contexts and projects. It is not comprehensive, but contributes some initial reflections on where and how opportunities exist for scaling out CBA pilot projects."