This paper presents the energy savings in refurbishment of the buildings using Life Cycle Assessment at material level by comparing three insulation materials that offer higher thermal performance and greater environmental sustainability. The comparison is made on products having the same insulation performance (U-value). After the enumeration of intervention practices for energy saving in buildings, the Life Cycle Assessment methodology in refurbishment of the buildings is applied at material level using Life Cycle Inventory to transform material volume input into impact on the environment as output. The Life Cycle Assessment (LCA) was carried out according to the requirements of the Environmental Product Declaration (EPD). After assessing the building performance before and after isolation, the "embodied energy", which comes from the materials manufacturing as phases of the refurbishment of the buildings, was determinate and compared with the operational energy of the building. This LCA methodology in refurbishment of the buildings at material level was evaluated for Expanded Polystyrene (EPS), Extruded Polystyrene (XPS) and Rigid polyurethane (PUR) insulation products. This methodology has been used on a building in Galati, Romania (School No. 9). A spider diagram was used to represent the criteria in a consistent, graphical way in relative units. The extreme values for a given criteria indicate the poor performance of the insulation material. Finally, the assessment of the building performance before and after using the insulation and the determination of the "embodied energy" compared to the operational energy of the building resulted in a 55% energy saving in the use stage of the building after refurbishment. (C) 2014 Elsevier B.V. All rights reserved.