The model for estimating the whole life costs of the building life cycle that allows the quantification of the risk addition lets the investor to compare buildings at the initial stage of planning a construction project in terms of the following economic criteria: life cycle costs (LCC), whole life costs (WLC), life cycle equivalent annual costs (LCEAC) and cost addition for risk (ΔR_LCC). The subsequent stages of the model development have been described in numerous publications of the authors, while the aim of this paper is to check the accuracy of the model in the case of changing the parameters that may affect the results of calculations. The scope of the study includes: comparison of the results generated by the model with the solutions obtained in the life cycle net present value method (LCNPV) for time and financial input data, not burdened with the risk effect; the analysis of the variability of results due to changes in input data; analysis of the variability of results as a consequence of changing the sets of membership functions for input data and methods for defuzzification the result.

Environmental protection is one of the objectives of the implemented concept of sustainable development and circular economy. The construction industry and its products (building objects) have a large contribution in negative influences, therefore all actions limiting them are necessary. One way of doing this is to apply substitution to existing unfavourable solutions, both in terms of construction and materials as well as technology and organization. The aim of the article was to determine the key factors conditioning the use of substitution at each stage of the investment and construction cycle, leading to environmental protection. The research paid attention to the use of substitute recycled products. The defined factors were subjected to a SWOT analysis and then, using the DEMATEL method, cause-andeffect relationships were identified that determine development in the application of substitution in the environmental context of sustainable and closed-cycle construction. The analysis was carried out by using a summative, linear aggregation of the values of the position and relationship indicators.

A new thambematid species, Thambema thunderstruckae sp. n., is described from King George Island, South Shetland Islands, Antarctic. Specimens of the new species were collected during two Polish Antarctic Expeditions in 1985 and 2007. It is the first record of this family from the Southern Hemisphere. The new species most closely resembles Thambema golanachum Harrison, 1987 and T. fiatum Harrison, 1987 but can be distinguished from both species by the shape of male pleopod 1, the number of claws on pereopods 2–7 and the setation of pereopod 1 and 2 carpus, respectively. A key to all known genera and species in the family Thambematidae is also provided.