Residential buildings in Greece account for about 79% of the exclusive-use building stock and consume about a quarter of the total final energy consumption, with space heating and domestic hot water being the main energy end-uses. About 58% of the dwellings were constructed before the 80 s and the adoption of the first thermal insulation regulation. This paper presents the results from the Hellenic pilot action within EPISCOPE. The overall approach and analysis are based on the national TABULA residential building typology for single- and multi-family houses in order to estimate heating energy performance and savings. The work exploits Census and statistical data for defining the Hellenic building stock and empirical adaptation factors to make more realistic estimates from normative calculations. The analysis is supported by a detailed data disaggregation in terms of the number of dwellings and floor areas, based on envelope thermal characteristics, heat production units, energy carriers, use of renewables etc. The calculation results are adapted for the building types and then projected to the building stock. Numerous scenarios for different modernization rates are assessed for identifying the most promising refurbishment strategies in space heating and DHW for reaching the 2020 and 2030 national CO2 emission targets. (C) 2016 Elsevier B.V. All rights reserved.