Calculation of cost-optimal combination of building materials and technical systems for nZEB single-family house using global cost calculation method

¹ The Faculty of Physics, Mathematics and Optometry, University of Latvia, Latvia
² Department of Infrastructure, University of Latvia, Latvia

^* Corresponding author: stanislavs.gendelis@lu.lv

Abstract

As a rule, during the design stage of a single-family house, only initial costs are taken into account and optimised. Long-term financial calculations are usually not even made. At the same time, total costs to design, build and operate the building show a real difference in expenses while living in this house. In the case of nearly zero energy buildings (nZEBs), this global cost approach becomes especially useful because of the strict requirements of heating and primary energy, as well as the compulsory use of renewable energy sources, requiring more detailed and comprehensive calculations of a cost-optimal set of solutions. In this study, a nZEB single-family house is analysed in detail using a comparative global cost calculation methodology. Different insulation materials and construction types, as well as two types of windows and various heating systems, are combined to obtain the same calculated annual energy consumption. The economic calculations of each combination are carried out for the calculation period of 30 years, taking into account expected energy price increase, discount rate, etc. These calculations show the cost-optimal variants, allowing the prediction of a more advantageous selection of materials and system use in a nZEB in terms of the real operation costs.