Optimisation on the thermal insulation layer thickness in buildings with environmental analysis: an updated comprehensive study for Turkey’s all provinces

This study determines the optimum insulation layer thickness to be applied external building walls considering heating degree-day (HDD) method, then energy saving costs, payback periods, and carbon dioxide (CO2) emissions are calculated accordingly. The optimisation analysis is performed for four different thermal materials (glass wool, rock extruded polystyrene, expanded polystyrene). Natural gas chosen as fuel purposes, horizontal perforated brick preferred in wall. One of original features this environmental determine CO2 emission insulated wall Turkey provinces. Another feature that it has most up-to-date data about HDD values material costs. worst best obtained wool glass respectively. case varied between 0.07 m 0.23 m, depending on annual total cost range 4.4–53.5 $/(m2year), period 0.11–0.38 years. Besides, reduction changed 53.2% 94% case, compared uninsulated