Some bricks do not need additional insulation, such as this one with U=0.11: https://www.heluz.sk/sk/vyrobek/heluz-family-50-2in1-brusena https://www.heluz.sk/s

Some bricks do not need additional insulation, such as this one with U=0.11: https://www.heluz.sk/sk/vyrobek/heluz-family-50-2in1-brusena https://www.heluz.sk/sk/vyrobek/heluz-family-50-2in1-brusena