Table 4.
Insulation thickness (mm) for concrete and CLT envelops in Korean apartment

Building envelop	Region	U-value criteria (W/m2·K)	Concrete envelops		CLT envelops		Diff.
			Concrete thickness (Tc)	Insulation thickness (Ti)	CLT thickness (Tclt)	Insulation thickness (Ti)
Wall faced outdoor air	Central	0.21 or less	180	152	180	109	43
	Southern	0.26 or less	180	121	180	77	44
	Jeju	0.36 or less	180	84	180	41	43
	Passive	0.15 or less	180	217	180	173	44
Roof faced outdoor air	Central	0.15 or less	180	217	180	174	43
	Southern	0.18 or less	180	180	180	136	44
	Jeju	0.25 or less	180	127	180	83	44
	Passive	0.12 or less	180	274	180	231	43
Bottom floor	Central	0.26 or less	180	108	-	-	-
	Southern	0.31 or less	180	87	-	-	-
	Jeju	0.41 or less	180	60	-	-	-
	Passive	0.15 or less	180	204	-	-	-
	Interlayer floor	Central	0.81 or less	150	21	150	0	21
		Southern
		Jeju