About us
Before founding Prototype, I gained experience in structural design across various property development projects. Though not particularly stimulating, this work allowed me to develop a solid understanding of modern construction techniques and implementation. It was during the study of prestigious architectural projects that my passion for the field of historical heritage emerged. This newfound interest led to the development of a specialized approach, which gradually evolved into a precise and rigorous methodology tailored to the restoration of historic structures. While traditional materials like lime mortar may seem less efficient compared to modern alternatives such as cement, historical buildings exhibit remarkable durability. To intervene appropriately, it is essential to study and comprehend the underlying reasons for this resilience and the design principles employed by the original builders. By closely observing structural issues and analyzing expert opinions, particularly those of skilled journeyman builders, I gained valuable hands-on experience. The work conducted in design offices is often disconnected from the reality of construction, especially when it comes to historic restoration. Static models, commonly used in contemporary construction, are frequently inadequate for addressing the nuances of older materials. Additionally, the vast wealth of traditional craftsmanship creates a gap between theoretical knowledge and practical application. Unlike an engineer's knowledge, which is largely theoretical, a builder's expertise integrates materials, tools, and techniques into a cohesive understanding. Each project presents unique challenges, requiring tailor-made solutions that reflect the diversity of builders' experiences. This insight has enabled me to develop precise diagnoses suited to the specific pathologies of traditional building materials.
Cedric Evrard
Missions
Office for the study of structures of ancient and listed buildings
Health status
Diagnosis and analysis of the existing situation
This preliminary analysis of the existing structure allows us to identify key structural elements and any visible damage, providing a clear understanding of the building’s unique characteristics. It helps us assess both its strengths and vulnerabilities. To gain a more comprehensive view of the building’s condition, it is often necessary to conduct soundings, sometimes even during the construction phase. These soundings help to better characterize the materials in use, determine their thickness, and understand the overall structural dynamics. The ultimate goal of this assessment is to recommend appropriate and targeted intervention strategies. In some instances, additional studies are needed to complete the diagnosis. These may include a detailed geometric survey, a geotechnical soil investigation, and a parasitic inspection to detect the presence of fungi or wood-destroying insects such as termites. These further evaluations ensure a holistic understanding of the building’s condition, allowing for precise, well-informed decisions during restoration or conservation efforts.
Project study
Static calculation, technical drawing and prescription
During a structural study, my role is to manage the technical aspects and provide support throughout the entire process. This process unfolds in several distinct stages. The first stage, known as the preliminary project, focuses on defining the construction principles best suited to the existing structure and identifying any elements that may have a significant financial or spatial impact. During this phase, the emphasis is on finding simple, practical construction solutions to ensure smooth project execution. By the end of this stage, key decisions regarding technical and material resources are made in consultation with the stakeholders during the initial coordination meeting. The next stage involves the detailed study of the technical file. Here, I apply the previously defined construction principles to the entire project, carefully checking the dimensions of each structural element, refining the details, and rationalizing and optimizing the overall structure. This phase also includes the preparation of tender documents, which complement the technical drawings with detailed specifications and quantities. These documents are presented at the second heritage meeting, marking a critical milestone in the project’s development. At each stage, the goal is to ensure that the project balances technical rigor with respect for the building's historical integrity, while also being mindful of cost, efficiency, and the specific requirements of the restoration or transformation. Next comes the study of the technical file. At this stage, I apply the defined principles to the entire project and check the sizing of each structural element, mastering the details, rationalizing and optimizing the structure. This phase also includes the drafting of the tender documents, which supplement the technical drawings with specifications and quantities. These documents are presented at the second heritage meeting, marking a new decisive step in the project.
Construction site monitoring
This service encompasses the ongoing oversight necessary to ensure the project is executed with precision and in line with design intentions. It includes participation in site meetings and regular visits to address specific issues related to structural stability, as well as making adjustments to plans and calculations based on any technical feedback that may arise during construction. Additionally, unforeseen discoveries on site—such as hidden structural conditions or unexpected material degradation—may necessitate further studies or design revisions. This continuous monitoring ensures that all modifications are seamlessly integrated into the project, while preserving both its technical integrity and overall viability. The primary objective is to guarantee that every phase of the project adheres to strict standards of safety, stability, and quality, all while respecting the unique challenges that come with working on a historic building. By staying involved throughout the process, I ensure that the evolving demands of the restoration are met without compromising the original vision or the building’s heritage value.
