In this new paper, which is a collaboration between academic and private sector researchers, we build a microsimulation framework for modelling Covid-19 disease transmission within communities.we find that an earlier lockdown is estimated to result in a lower peak in COVID-19 cases and 47% fewer infections overall during the initial COVID-19 outbreak. Input data for the model comes from a range of research projects, including population estimates from my Turing funded SPENSER project.