Hempcrete is a carbon-negative, non-toxic, breathable, and biodegradable building mate-rial. Nevertheless, the utilization of hempcrete in the construction industry remains low, mainly due to the high-variability of hemp-lime composites. Therefore, the development of locally available products, standards, and best practice guidelines requires comprehen-sive experimental tests and analysis to obtain reliable information about the material’s thermophysical performance. The aim of this study was twofold: (1) development of hempcrete infill “wall” formula with excellent thermal properties using locally sourced materials; and (2) numerical investigation of the long-term hygro-thermal performance of hempcrete wall types that satisfy current National Energy Code of Canada for Buildings. The thermal properties of the hempcrete were obtained with heat flow meter Fox314, whereas the hygrothermal analysis of wall assemblies was performed using WUFI soft-ware. The densities of hempcrete samples produced in this study show excellent con-sistency, ranging from 298.55 kg/m3 to 318.05 kg/m3, with the average density of all sam-ples is 306.13 kg/m³. Furthermore, the average thermal conductivities of all the samples range from 0.081 W/mK to 0.089 W/mK, with a standard deviation of 0.004–0.007 indi-cating consistency in the results. The results of the modeling analysis show that the aver-age water contents in the mass percent of both wall assemblies under all four cases are significantly below the 20 mass-percent. Nevertheless, on average, the base wall has 36% to 54% higher water content than the multilayer wall throughout the simulation period. Moreover, RH profiles of both walls have regular patterns of seasonal fluctuation that gradually decrease over time, and especially of the multilayer wall, which under all sce-narios, has lower RH compared to the base wall. The multilayer wall performs better and exhibits lower annual heat flow than the base wall under all cases, and in particular, at the outside surface. The likely reason is the addition of the insulation layer that reduced heat losses at the external surface of the multilayer wall. Furthermore, due to the higher indoor air temperatures of cases II and IV than the other two, both walls have higher heat flow under II than I scenario and under IV than III scenario.