Space heating in cold climates requires large quantities of heat energy to be spent. Therefore, considerable energy-savings can be obtained using construction wall materials with low thermal conductivity in the buildings. In this study, an economic analysis (LCC analysis) was performed in order to estimate the optimum thickness, saving and pay-back period which minimizes the total cost including the masonry material and the energy consumption costs. The LCC analysis was carried out for external walls of buildings in Afyonkarahisar, Turkey. Considering long term and current outdoor air temperature records, degree-days (DD) values were used, and the variation of annual energy requirement of the building was investigated for various masonry (product) types for per unit area. Masonry products were block elements with one, two, three and four row-hollows, hollow-brick and aerated concrete. As the fuel types, fuel-oil, natural gas, coal and electricity were considered in the analysis. The functional unit of the LCC was the use of 1 m(2) of the building's living area over 50 year's period. As a conclusion, the highest energy-saving was obtained by the use of hollow blocks with 4 rows. Moreover, the most suitable fuels for all climate zones appear to be electricity and fuel-oil. But, the natural gas is a better choice when the atmospheric pollution is an important consideration. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.