Energy and Buildings 78 (2014) 35–42 Contents lists available at ScienceDirect Energy and Buildings j ourna l ho me page: www.elsevier.com/locate/enbuild Thermal insulation alternatives of historic brick buildings in Baltic Sea Region Jurgis Zagorskas a , Edmundas Kazimieras Zavadskas a,∗ , Zenonas Turskis a , Marija Burinskien ˙ e a , Andra Blumberga b , Dagnija Blumberga b a Vilnius Gediminas Technical University, Saul ˙ etekio al. 11, LT-10223 Vilnius, Lithuania b Riga Technical University, Kronvalda bulv ¯ aris 1, LV1010 Riga, Latvia a r t i c l e i n f o Article history: Received 5 February 2014 Received in revised form 25 March 2014 Accepted 2 April 2014 Available online 18 April 2014 Keywords: Historic buildings Retrofit Energy performance Fac ¸ ade insulation MCDM TOPSIS with grey numbers a b s t r a c t The growth in building refurbishment works is creating a demand for suitable materials, retrofitting techniques and research. The differences between refurbishment of new-build projects and historical or valuable buildings are insufficiently recognized – mostly the buildings without further cultural preser- vation requirements are studied. This article covers the theme of retrofitting the historical buildings, when due to the valuable fac ¸ ade or other heritage preservation requirements only the inside insulation is allowed. The problems of moisture in brick wall construction, loosing space, etc. are discussed and method for selecting best insulation option is shown. The 5 modern insulation materials are selected, measurements are made and best alternative is found using TOPSIS method with grey numbers. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Climate change and global warming are recognized as one of the largest and the most serious problems humankind is facing in this century. Climate scientists have provided analyses that yield very high confidence in rises of human-caused greenhouse gases. This process will lead to the sequence of environmental and economic losses [1]. The policy sector drove that research and the result has been an ever-increasing call for worldwide reductions in green- house gas (GHG) emissions [2,3]. Buildings are a crucial sector for controlling energy demand because currently buildings account for around 30% of the total energy use in the world [4,5]. The buildings as energy consummators are important also because they will con- sume future energy. Thus, failing to retrofit old buildings to improve their energy and environmental performances may endanger GHG mitigation [6]. Fig. 1 shows the part of energy consumed in build- ings with low energy efficiency. The current policy attempts concentrate on creating the build- ing energy performance certification system which will be applied ∗ Corresponding author. Tel.: +370 69820779. E-mail addresses: jurgis.zagorskas@vgtu.lt (J. Zagorskas), edmundas.zavadskas@vgtu.lt, e.zavadskas@gmail.com (E.K. Zavadskas), zenonas.turskis@vgtu.lt (Z. Turskis), marija.burinskiene@vgtu.lt (M. Burinskien ˙ e), andra.blumberga@rtu.lv (A. Blumberga), dagnija.blumberga@rtu.lv (D. Blumberga). not only to the new, but to all existing buildings, including the ones with historical value. It is clear that the improvement of build- ing energy performance and certification can act as a catalyst for behavior change of all building-users [7,8]. However, the historic buildings usually have limited retrofitting possibilities and can be shifted by two-three energy efficiency labels only (e.g. from class F to class C or D). The energy performance standards for this cate- gory of buildings in most European countries are not applied at the moment, but the current trends in policy show that this can change in near future. With every year number of building refurbishment works is growing and in many economically developed countries worldwide is now taking about 50% of all building construction market [9–11]. The main reason for this tendency is, of course, the increasing price of energy and the will of stakeholders to pay less for the main- tenance of the building. According to the changes in construction market it can be predicted that today’s homes will comprise at least 80% of the 2050 housing stock and because of rising prices on energy they will need to be retrofitted for better energy performance [12]. A significant part (from 20% to 30% in European countries) of these buildings have unique outlook which has to be preserved. 2. Studies on historic building refurbishment Energy and sustainability are a hard challenge in building her- itage, both the technical solutions in order to solve impact of energy http://dx.doi.org/10.1016/j.enbuild.2014.04.010 0378-7788/© 2014 Elsevier B.V. All rights reserved.