Historically, there has been an expectation that autistic children and adults should conform their behaviour to social norms, with strategies and interventions centred around navigating spaces and situations with minimal damage. This person-centred environmental assessment and modification programme moves away from this, with the aim to provide information and tools for assessing and reflecting on features of the autistic person's environment to best support their comfort, autonomy and agency. Written as a collaboration between autistic and non-autistic professionals, the authors break down each environmental element (physical, sensory, emotional, communicative and social) by chapter and include checklists as reference points to equip the reader with a framework from which to begin. This accessible, strengths-focused approach to supporting autistic people across different areas of their life reflects a paradigm shift from one where autism is treated as a deficit or impairment to one of strength, acceptance and autonomy.