BACKGROUND 1.1 | The problem: Limited evaluation of social and gender equality outcomes of water, sanitation and hygiene interventions Safely managed water, sanitation and hygiene (WASH) services are viewed as fundamental for human wellbeing, enabling a range of positive outcomes related to health, education, livelihoods, dignity, safety, and gender equality. Progress in providing WASH services and thus achieving these outcomes has not occurred equally, with a range of inequalities in who can access and benefit from WASH services across varying socio-cultural contexts, geographical areas and socioeconomic settings. For instance, among the 785 million people who lack a basic drinking-water service, and 2 billion who lack access to basic sanitation services, a greater proportion are poor and living in rural areas (WHO/UNICEF JMP, 2019). Further, unsafely managed water and sanitation disproportionately impacts a number of social groups, including women, girls, and sexual and gender minorities, people with disabilities, people marginalised due to ethnicity, caste, poverty or other factors, and those living in vulnerable situations such as displaced people or people who are experiencing homelessness. As the COVID-19 pandemic disproportionately affects particular groups of people, it has the potential to exacerbate many of these existing WASH inequalities (Howard et al., 2020).Gender inequalities related to WASH are particularly large, as women and girls have specific needs related to biological factors, and experience strongly gendered norms surrounding water and sanitation, such as expectations of carrying out water fetching, caregiving and hygiene roles within the household (Caruso et al., 2015). In many countries where women and girls are responsible for water fetching this contributes to a substantial burden of musculoskeletal disease (Geere & Cortobius, 2017). Additionally, women and girls are more negatively impacted by a lack of private and safe sanitation facilities,