This recently-launched, two-year ESRC-funded study breaks new ground in researching 0-3-year-old children's language and literacy play at home in the digital age, in diverse communities across the four UK nations. Digital technologies feature prominently in contemporary family life (Chaudron et al. 2018; Kumpulainen & Gillen 2020). Even very young children observe and use language playfully in digitally-mediated activities, e.g. e-books, digital toys and interacting via mobile devices (Arnott et al. 2019; Zhao & Flewitt 2020). Drawing on social semiotic theory (Kress 2010), socio-materiality (Barad 2003; Murris 2016) and respecting young children’s participation rights, the study builds empirically-grounded conceptualizations of 0-3-year-olds’ engagement with today’s technology-rich cultural artefacts, where play and meaning making are entangled with ‘humans, nonhumans and more-than-humans’ (Kuby & Rowsell 2017: 285). The multi-phase study design offers a template for interdisciplinary research, including iterative innovation in participatory approaches to researching the home. Research methods include an online survey, remote interviews with families and professionals, followed by 40 in-depth case studies. In alignment with our conceptual and theoretical approach, we emphasise the interpersonal, responsive nature of research ethics, using creative approaches to ensure informed and voluntary child and adult consent. This paper critically evaluates how the study will generate findings related to researching the home environment collaboratively and sensitively with young children and their families in diverse communities. Here, we focus on research impacts, including multi-phase research design and a palette of participatory methods from which families can choose the approach most apt for their circumstances, including self-generated data.