Heritage buildings possess architectural, aesthetic and historical values. Mysore has many such heritage buildings, and these buildings need renovation. The renovation should be performed with lime mortar, which has been extensively used for centuries in construction due to its durability, flexibility, workability, plasticity, and good adhesive property. Lime mortar is mainly preferred in the renovation of heritage buildings than cement-based mortars because it is breathable, allowing moisture to evaporate and preventing trapped water that can harm historic structures. An attempt has been made to look into renovation of Government (Govt.) Ayurveda college at Mysore which is about 116 years old. Govt. Ayurveda college was recently renovated with lime mortar. The different admixtures used along with lime mortar for renovation are beal fruit, antuvala kayi, alale kayi, jaggery, and M-sand. The main objective of this study is to compare the embodied energy of traditional lime mortar used in Government Ayurveda Medical College, Mysore, and modern cement-based mortars. Assessing embodied energy helps to understand the environmental impact of a product by considering energy inputs beyond its immediate use phase.