This chapter explores the rationale for a pension fund to integrate sustainability in its investment analysis and decisions, and why engagement is an important tool for an active and long-term investor in creating value for beneficiaries. Based on our experiences this does not neccessarily carry the higher costs traditionally associated with active management, but it will put higher demands on asset managers and analysts to understand and translate new data and information into the fundamental financial analysis. In a time where increasing capital is being allocated to passive index strategies, we argue that active and long-term owners foster corporate accountability and a broader concept of value creation. We stress the importance of developing in-house capacity for engagement and stewardship, as this enables leverage on key industry insights, while at the same time recognising when investor collaboration towards a common objective is more efficent.