The article deals with the influence of the floor area of house energy supplied to the hot water. Mutually compare three methods of calculation and one of them use in the calculation of delivered energy for hot water system, through which energy class is designed for local consumption - the warm water.

Newly established program “Green Savings” based on income from CO₂-emissions trade (Green Investment Scheme) brings several variants how to apply for subsidy for energy efficient building/renovation. Following text describes possible approaches to renovation with use of both thermal insulation of exterior constructions and change of windows/doors. Two examples of typical family houses are being described, each house in two variants of insulation (based on subsidy program criterion).
Important result is that almost all family houses that can be insulated with use of “partial insulation” subsidy, could gain higher subsidy with use of “complex insulation” criterion as well. Previous practice shows that majority of family houses can reach the higher subsidy (“complex insulation”).

Different prediction methods for the Sound Reduction Index of single building structures in laboratory conditions and for the Apparent Sound Reduction Index in buildings are presented in following paper. A short discussion of methods is done regarding to input data, assumptions of calculations etc. The main part of this paper is focused on a comparison between predicted and measured results, which leads to evaluation of methods´ accuracy. This paper is based on author´s PhD thesis.