“…As illustrated in Fig. 2, Italy is the country that has generated most of the energy efficiency in historic building research [6,14,15,18,20,26,30,32,35,40,41,43,47,[49][50][51][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74]. Italy is followed by the UK [21,25,[75][76][77][78][79][80][81][82], Spain [19,54,[83][84]…”