Domestic Energy Models have been used in the UK to energy rate buildings since the 1980’s. They have become a critical tool for policy makers, building regulations and helping homeowners decide what homes to purchase, rent and refurbish. Domestic energy models all need grounding in empirical data. The roll-out of smart meters has radically changed the accessibility of empirical data. This presentation reviews results from 13,000 homes where metered and modelled data with is compared.