Between Respect and Innovation. Innovative Recovery and Extention of a Historic Rammed Earth Farmhouse in Novi Ligure, Italy

This paper presents the restoration and refurbishing project of a historic farmhouse located in the rural area of Novi Ligure (AL), Italy; it’s the Italian reachest area of rammed earth heritage. The building, a rectangular structure (22 x 6 m) standing three stories high (9 m), has load-bearing rammed earth walls and pavilion vault brick floors. Initiated in 2012, the project aimed to renovate the residential areas, repurpose rustic sections for habitation and expand westward. The design process focused on respecting the original earthen building technology and structural behaviour, while prioritizing sustainability and energy efficiency. The new extension was built using cross-laminated timber (CLT) panels and insulated with wood fiber, featuring a green roof to enhance thermal performance at ground level. This addition was designed to align with the comfort and indoor health standards set by the historic rammed earth structure. The existing structure underwent targeted structural interventions based on an in-depth analysis of its original construction. These interventions honored traditional earthen construction techniques while integrating modern materials and technology. Thermal and hygrothermal strategies were also carefully adapted to the unique properties of the rammed earth, ensuring compatibility with its physical and performance characteristics. Innovative solutions included the use of CLT and steel for new floors, lime-based mortars and screeds, and a novel approach to reinforcement. For the first time, fiber-reinforced mesh with an organic lime matrix, secured by stainless steel helical bars, was applied in place of traditional structural bracing for the (new) openings and the chains reconnecting disjointed wall sections. Additionally, an experimental 18 cm layer of lime and glass-cell microsphere thermal plaster was applied externally, achieving an insulated yet “monolithic” appearance that enhances structural integrity. This project serves as a model for sustainable restoration, combining traditional earthen techniques with contemporary materials to meet modern performance (and economic) requirements.