The paper presents an approach to evaluating a building throughout its whole life cycle in relation to its sustainable development. It describes basic tools and techniques of evaluating and analysing the costs in the whole life cycle of the building, such as Life Cycle Assessment, Life Cycle Management, Life Cycle Cost and Social Life Cycle Assessment. The aim of the paper is to propose a model of cost evaluation throughout the building life cycle. The model is based on the fuzzy sets theory which allows the calculations to include the risks associated with the sustainable development, with the management of the investment and with social costs. Costs incurred in the subsequent phases of the building life cycle are analysed and modelled separately by means of a membership function. However, the effect of the analysis is a global cost evaluation for the whole life cycle of the building.
Accommodation tourist industry is characterized by high variability. For this category of services not only the location is crucial- that does not change, but also the standard, prices and seasonality of services. In the recent years, leisure centers performing functions only during the summer time have seen the possibility to extend their activities beyond the summer months. The reasons for this are the local investments requiring qualified staff which comes from different parts of the country, Europe and the world while creating dernand for accommodations. To meet the possible demand needs and to adapt to cold season, performing thermo-modernization works is necessary. In order to find the best solution and answer those needs, analysis of the profitability of the investrnents in a chosen holiday resort was carried out. The article presents the results of the analysis based on the payback period, LCC analysis and assessment of the investments risk.