Table 3.

Aggregated findings of different basic insulation materials are sorted by ‘Thermal Conductivity—Weight Ratio’ in descending order.

Insulation Material	Thermal Conductivity at 10 °C, λmin–λmax [W·m−1·K−1]	Dry Density (Own Mean.), ρmin–ρmax [kg·m−3]	Bio 1	Reference	Average Thermal Conductivity *, λAvg [W·m−1·K−1]	Average Density *, ρAvg [kg·m−3]	Thermal Conductivity-Weight Ratio *, 1/(λAvg·ρAvg) [W−1·kg−1·m4·K]
Vacuum Insulation panels (VIP)	0.004	160–200	N	[6,57]	0.004	180	1.389
Polyurethane rigid foam (PUR)	0.020–0.030	30–45	N	[51,52]	0.025	38	1.053
Expanded polystyrene (EPS)	0.030–0.040	15–40	N	[53,54]	0.035	27.5	1.039
Sheep wool	0.032–0.054	10–40	Y	[60,61,62]	0.043	25	0.930
Extruded polystyrene (XPS)	0.028–0.040	25–45	N	[55,56]	0.034	35	0.840
Cellulose Fibers	0.036–0.042	40–70	Y	[63,64]	0.039	55	0.466
Wheat + mycelium Trametes versicolor	0.042	94	Y	[12]	0.042	94	0.252
Hemp + mycelium Trametes versicolor	0.040	99	Y	[12]	0.040	99	0.250
Mineral Wool	0.034–0.045	120–140	Y	[58,59]	0.039	130	0.197
Wheat + mycelium Ganoderma lucidum *	0.043–0.056	107–156	Y	Current research	0.048	138	0.148
Cork	0.040–0.050	80–240	Y	[65,66]	0.045	160	0.139
Flax + mycelium Trametes versicolor	0.058	135	Y	[12]	0.058	135	0.128
Flax + mycelium Ganoderma lucidum *	0.045–0.047	146–220 *	Y	Current research	0.046	171	0.127
Hemp + mycelium Ganoderma lucidum *	0.045–0.050	119–227	Y	Current research	0.047	172	0.123
Soybean straw + Mycelium Ceriporia lacerata	0.054	160		[67]	0.054	160	0.116
Rapeseed bagasse + mycelium Ganoderma lucidu	0.057	156	Y	[36]	0.057	156	0.112
various substrate materials + mycelium Irpex lacteus	0.060	180	Y	[35]	0.060	180	0.092
Bark fiber	0.044–0.063	164–276	Y	[68]	0.0535	220	0.084
Flax + waterglass	0.066–0.068	235–284	Y	[31]	0.0672	259.5	0.057
Cotton Stalks	0.058–0.081	150–450	Y	[2,27]	0.070	300	0.048
Hempcrete	0.057–0.066	389–441	Y	[32]	0.0619	365	0.044
Light-earth	0.060–0.120	190–353	Y	[69]	0.090	271.5	0.041
Cellulose fiber + mycelium Ganoderma lucidu	0.085	373		[36]	0.085	373	0.031
Timber (softwood)	0.130	500	Y	[70]	0.130	500	0.015

Legend: *—Established averages by the authors, Bio ¹—Biodegradability (N—No, Y—Yes).