19 February 2026
In a time of evolving legislation and heightened focus on sustainability, comprehensive, up-to-date guidance for strategic assessment has never been more crucial. Much existing guidance is now dated, and practitioners across the UK have told us they need a modern, flexible resource. This guide meets that need.
Our advice is for everyone involved in strategic assessment, whether you work in local authorities, consultancies, statutory bodies, or community groups. It’s designed to be useful regardless of the regulatory regime or the type of plan, policy, or programme you’re assessing. It should prove equally useful to practice whether applied to a strategic assessment in the form of Strategic Environmental Assessment (SEA), Sustainability Appraisal (SA), Integrated Impact Assessment (IIA), or any other tool that seeks to achieve a similar influence.
The guide moves away from a ‘one-size-fits-all’ approach. Instead, it emphasises proportionality, encouraging you to tailor the assessment to the plan’s place in the planning hierarchy and its specific context. You’ll find practical examples, case studies—like those on Future Wales and HS2—and clear advice on everything from screening and scoping to assessing alternatives, cumulative effects, and effective reporting.
Readers will gain actionable insights to produce more focused, relevant, and impactful assessments that genuinely improve sustainability outcomes, avoid lengthy documentation, and engage stakeholders effectively.
This guide reflects the collective expertise of our diverse Working Group and is intended to support the ongoing evolution of practice. I encourage you to use it, share it, and help us all deliver more sustainable planning for the future.
