Sustainability is an important factor in designing vernacular architecture, including vernacular palace architecture; the latter refers to low-rise buildings similar to Traditional Malay Houses (TMH). However, the Istana Lama Seri Menanti is a 4-storey mid-rise vernacular palace which was designed with sustainability in mind. This mid-rise element of the palace communicates the vernacular architecture of TMH in Negeri Sembilan whereas sustainable designs are factored in environmentally friendly materials, construction methods, and the environmental impact of the building culturally and economically. This research was aimed at examining the sustainability approach of Istana Lama Seri Menanti as a mid-rise vernacular palace in the early 20^th Century, and its impact on the current generation after 109 years. The research methodologies include case and precedent studies of vernacular palaces in Malaysia as well as interviews with experts in the field. In conclusion, the architectural sustainability of Istana Lama Seri Menanti had taken into account timber availability, consumption of naturally available resources, designs with minimal environmental impact and high cultural importance in the building design with the ultimate aim of conserving it for future generations.