This document summarizes the renovation of a 17th century heritage building in Mellé, France into an eco-housing demonstration. The renovation combined energy efficiency, use of natural materials, and local expertise. Various insulation techniques were used on different walls, including interior lime-hemp brick, exterior wood fiber, and a timber frame. Ground floor insulation addressed radon risks. The project cost over £110,000 and achieved an air change rate of 0.73 m3/h.m2. It serves as an educational tool to showcase sustainable renovation of heritage structures.