Mould growth is governed by a complex set of factors, including among others physical characteristics of a given indoor environment, as well as how that space is used, i.e. heating, cleaning and ventilation habits, however how and to what extent these define propensity to grow mould is unclear. This study uses data from a testing scheme on 84 rooms in 18 properties to shed further light on these questions through elastic net regression analysis. The testing data includes the air and surface mould readings quantified based on the activity of β-N-acetylhexosaminidase (EC 3.2.1.52; NAHA), and particle intensity in each room.