In order to meet the energy performance regulations for new buildings and to improve the energy performance of the existing building stock, a high amount of insulation materials will be needed in the coming years. Meanwhile, the demand for renewable materials and materials with a low environmental impact is increasing. In previous research, the ecological and hygrothermal potential of lime hemp as a building material has been shown. Besides incorporating a large share of renewable and fast-growing hemp shives, lime hemp combines thermal insulating properties and a high thermal inertia with a good moisture regulating behaviour. However, despite the growing interest in the material and promising lab results, the thermal performance in real conditions is still uncertain. Due to the lack of validated data for in-situ cast walls, rather conservative λ-values for lime hemp are currently compulsory used in energy performance certification calculations in Flanders, the Flemish region of Belgium.

In this paper, the results of a case study analysis of four real-life lime hemp projects are presented. The thermal performance of four dwellings with in-situ cast lime hemp walls (both new construction and renovation) is determined by in-situ measurements of the U-value. The measurements show that the in-situ U-value of the lime hemp walls is significantly better than the U-value that is calculated with the λ-value that is currently accepted by the Flemish Energy Agency. However, drying of lime is a slow process, resulting in initially higher U-values that gradually decrease in the first months after lime hemp application. Once dried, in-situ cast lime hemp walls can meet the Flemish energy performance requirements.

为了满足新建筑的能源性能规定并提高现有建筑的能源性能，未来几年将需要大量的绝缘材料。同时，对可再生材料和对环境影响较小的材料的需求正在增加。在以前的研究中，已经显示了石灰麻作为建筑材料的生态和湿热潜力。除了包含大量可再生和快速生长的大麻碎屑外，石灰大麻还结合了隔热性能和高热惰性以及良好的水分调节性能。然而，尽管人们对这种材料的兴趣日益浓厚，实验室结果令人鼓舞，但实际条件下的热性能仍不确定。由于缺乏现浇墙的验证数据，

本文介绍了四个现实生活中的石灰麻项目的案例研究分析结果。四个带有现浇石灰麻墙的住宅（新建和翻新）的热性能由 U 值的现场测量确定。测量结果表明，石灰麻墙的原位 U 值明显优于使用佛兰德能源署目前接受的 λ 值计算的 U 值。然而，石灰的干燥是一个缓慢的过程，导致最初的 U 值较高，在应用石灰麻后的头几个月逐渐降低。一旦干燥，现场铸造的石灰麻墙就可以满足佛兰德能源性能要求。