This project builds on a body of research and my personal and professional expertise focused on tobacco control and reducing second hand smoke exposure (SHSe) for marginalised groups and embedding collaborative public and patient involvement (PPI). We know smoking is a leading cause of premature mortality and morbidity globally, accounting for 8 million deaths (WHO 2023) and leaving no one behind is the goal of the UN SDGs by 2030. This study aims to explore with key multi-stakeholders (registered nurses and families who experience homelessness) to a) understand experiences supporting communities to reduce SHSe and b) explore how families reduce their SHSe in temporary/ sheltered homes.