The research elaborates various solutions using detailed economic evaluation and energy
efficiency calculation and simulation technology for formulating applicable, energy
and cost-efficient retrofit solutions of single-family residential buildings located
in temperate climate areas. Primarily the annual energy demand for a reference existing
single-family residential building was determined. The economic analysis was performed
for six formulated refurbishment scenarios in order to determine which of the scenarios
will demonstrate optimal performance both in energy and cost efficiency. A feasibility
study was performed for the most efficient scenario, which included an economic evaluation
of low temperature radiant heating systems were three energy suppliers (oil, natural
gas and electricity for air to water heat pump) were compared. According to financial
analyses the optimal scenario includes the replacement of windows, installation of
15 cm expanded polystyrene thermal insulation, low temperature radiant floor heating,
with a payback period of ten years.