A training session titled Lime in historic buildings: choosing the right mortars and avoiding pathologies will be held by BuildingLab on October 1st and 2nd, 2026. The event is designed for architects and professionals involved in the restoration of historic buildings, offering guidance on selecting and applying lime in ways that preserve the integrity of these structures. The session focuses on the unique behavior of historic masonry, which differs significantly from modern construction materials. It highlights the importance of using flexible and permeable mortars that allow for moisture movement and structural flexibility, as overly rigid or watertight materials can lead to issues like cracking, peeling, and the deterioration of stones and bricks. The training revisits the key differences between lime and cement, including their rigidity, permeability, setting process, strength, and how they react to humidity. Participants will learn to identify the main types of lime—such as aerial and hydraulic lime—and choose the right binder based on the materials being used, the project's purpose, and practical constraints. The goal is to understand when to use lime versus cement in historic restoration to prevent damage caused by incompatible materials. The session covers the primary applications of lime in renovation, including its production, physico-chemical properties, and how it compares to cement. It also explores traditional techniques like frescoes, broom coatings, and multi-layer finishes, as well as the use of lime with biosourced materials such as hemp. Real-world examples are used to help participants recognize common problems in historic buildings and link them to material choices or application methods. The training is led by Hugo Marion, a heritage architect and co-manager of Oriel Studio, an agency specializing in the restoration of historic monuments and buildings, as well as bioclimatic and low-tech projects. The session is based on his field experience, supported by visual examples and case studies from actual renovation projects. The event will be held online via Microsoft Teams, from 9 a.m. to 12:30 p.m. on both days, totaling 7 hours of instruction. The cost is 490 euros HT, which includes access to a replay, teaching materials, and a certificate. Funding options may be available through FIF PL or OPCO, depending on the participant's situation. The training is intended for a wide range of professionals, including architects, project managers, engineering firms, construction economists, restoration companies, artisans, and project owners. While a general understanding of buildings and renovation is recommended, no prior knowledge of lime is required. The session is also included with the BuildingLab annual subscription, which costs 990 euros HT per year and provides access to all training sessions, conferences, and a document database for 12 months.