While necessarily monitoring technical condition of bearing designs of unique buildings and structures, the same monitoring must be done to the items of their engineering systems. To do so, certain monitoring points are designed. The objective here is to make choice among rational measurement instruments taking into account some resource restrictions and several rationality criteria. It is also necessary to consider great uncertainty conditions of design and creation of unique buildings and structures. This involves participation of experts, whereas the fuzzy logic theories are supposed to be applied in order to process examination results. The article deals with an approach to designing some rational option for instrument structure of monitoring point, based on the analysis of integrated efficiency of the used measurement techniques to control technical condition of engineering systems. The way of transition from individual indicators of control devices’ efficiency to integrated efficiency indicators of the point of monitoring has been proposed, basing on the knowledgebase model in the form of production inference rules. Such an approach allows identifying the most effective measuring technique for each object of a unique building by a complex of certain indicators estimated by experts. The obtained results may bring about a significant cost reduction when solving a problem of instrument base justification for statistical methods of monitoring at the expense of refusing from time-consuming natural tests.