Biodiversity net gain (BNG) is a strategy to reverse biodiversity loss from infrastructure development projects, which is gaining traction with industry and governments. However, there is still a gap when it comes to incorporating knowledge and inputs of different stakeholders in an effective way to deliver BNG. I propose closing that gap would enable more effective design and delivery of BNG. In this research, I take the UK as a case study, and show how local government, industry developers and consultants, nationwide and local NGOs, and local interest groups can be brought together with the aim of delivering effective biodiversity net gain, with genuine, long-term and measurable outcomes. I conducted key informant interviews with experts within all these groups, and compiled project-specific case studies. I uncovered five major themes in my research, that show that more effective BNG can be achieved by incorporating previously excluded stakeholders, and having local authorities, record centres and even NGOs and local groups, rather than just industry, take some responsibility for making sure BNG is successful. I show the importance of designing BNG projects with adequate respect to landscape ecology, using qualitative assessments of biodiversity alongside quantitative metrics, and the need for effective monitoring and stewardship of projects to ensure long-term delivery. I show how in all five themes, closing the engagement gap can help deliver more effective BNG, although not without some uncertainty. Whilst contentious, I suggest that BNG could be a path forward for all stakeholders to a more biodiverse future.