Typically, studies of the occupiers' choice of office property have focused on the influence of location. Following the standard behavioural assumptions of neo-classical economics, the firm is assumed to make the rational profit-maximising decision on the basis of full information. All firms are implicitly assumed to be homogeneous. This general approach eliminates much of the complexity from the decision-making process. This paper uses evidence from a survey of over 100 office occupiers in Edinburgh to examine the influence of a broader range of factors on individual firms' choice of office. Using logistic regression techniques on the survey data, the empirical analysis shows that by taking account of heterogeneity of firms, it is possible to identify the type of property occupied. Firms' decisions are closely related to their size, business type and whether the market they serve is local, regional or national.