Asset management has an increasingly important role in organisations, as it can affect productivity and cost effectiveness, the useful life of facilities, the quality of processes, compliance with standards and safety and environmental laws, and more recently, to ensure more sustainable operations and use of resources. However, despite its importance in the provision of services to users, the buildings sector is deficient in contributions in the literature that: a) use an objective multicriteria model, and those developed in a fuzzy environment are even rarer; b) analyse the evolution of asset management in a country over an extended period of time; c) use weightings for each factor analysed, taken from judgements provided by experts in the buildings sector; d) consider all the full data for the sector, rather than average values; e) analyse the buildings complete sector and according to the size of the building. This paper, therefore, sets out a fuzzy multicriteria model for analysing the evolution of the asset management performance of the buildings sector by size (small, medium and large) in Spain from 2000 to 2020. The weightings of criteria and sub-criteria will be calculated based on the judgements of four experts in Spanish maintenance. 229 surveys carried out by the Spanish Maintenance Association are used, looking at all the information provided, rather than average values, developing discrete probability distribution functions to allow the uncertainty of the historical evolution of the asset management of buildings in Spain to be calculated. The average utility variation over the period 2000–2020 in the sector is 1.36 %. This value, although positive, is very low to cover a period of 20 years, and it seems that maintenance departments are not adapted to the new challenges of Industry 4.0.