The domain of Sustainable Development innovation is facing a significant transformation. Several trends, social, political, economical forces and players are concurring in the rise the concept of impact on sustainable development challenges. That is being introduces in the strategies of big and small enterprises, at different degrees, varying from innovations along the value chain to small adaptive tactics keeping the pace with the latest governmental regulation in matters of emissions reductions, workforce welfare etc. Moreover, a growing number of emerging startups already include sustainable development challenges in their DNA as a main mission -often called Impact Startups. However, being hybrids with ambitious impact change goals and financial sustainability needs, they often struggle to survive and develop models of impact. In this context, BMI Lab is a consultancy supporting organisations with business model innovation. The current process does not account for ‘impact drivers’ in the equation for business model generation, therefore does not have the capabilities to support impact startups, and will need to evolve to do so. The project arouse from the knowledge gap of including Sustainable Development Impact as an additional driver in business model generation. The aim is to provide a strategic design angle to complement the Business Model Design Sprint, based on an explorative approach over the impact factors and challenges in achieving impact models. First, the concept of impact model is defined, then based on field immersion, impact entrepreneurs and experts stories and interviews, and academic sources, the research identifies a set of critical activities that could positively influence the development of impact models. Those have been embedded in a toolkit. The toolkit takes place in the first day of a BMI Lab BM generation Sprint and aims at guiding through the identification of new opportunities that align SD goals and viability. It consist of four main stages focusing on the value exchanged with the ecosystem of intervention.