The heating degree-day method was used to determine the natural gas consumption by residential heating in Turkey. Cities located nearby the existing, under construction, and planned natural gas pipelines were chosen for this study. Degree-days, population and resident distribution records obtained for these cities were utilized to estimate the nation-wide natural gas demand. Our study indicates that the potential consumption in Turkey in 2023 could be as high as 14.92 Gm(3) if 100% of residences use natural gas for space heating. The results enable us to locate the distribution of energy demand and pick out the areas where consumption is highest. The predictive method was successfully validated by comparison with real data on natural gas consumption in Turkey for the winter heating of buildings. (C) 2003 Elsevier Science Ltd. All rights reserved.