Building Restoration: from surveying to documentation of degradation

Building Restoration is important to preserve high-value histotic buildings and requires great skills. Let’s find out all about this process

Building Restoration involves recovering a historic building to its original state and can be a complex process requiring a deep knowledge of the construction techniques and materials used in the past. Since a restoration aims at preserving a building’s heritage, architects must be guided by conservation principles paying attention not to cause irreparable damage in some cases. For this reason a buildingSMART Data Dictionary is fundamental.

This article will highlight different aspects of a restoration project, also through some practical examples, and will cover different phases and restoration interventions necessary to preserve and enhance our cultural heritage.

General procedure for the restoration of historic buildings

A project of restoration of a historic building is develop through several phases, which can be summarized in the following steps:

historic building’s survey and diagnosis of degradation phenomena – this allows you to know the actual state of the property and to report everything digitally thanks to HBIM (Historical/Heritage BIM) software;
historical studies and analysis of construction techniques or materials – is the collection of all documentation (images, plans, various technical drawings) and analyses which allows you to obtain all require information for the study of the building. It is important to refer to a BIM management system to better complete this phase;
designs for restoration and recovery interventions – when all the preliminary studies are completed, then we proceed with the specific designs for interventions which can improve the property’s condition;
restoration and interventions’ works – here all the interventions hypothesized in the design phase are put into practice. However, greater attention is focused on safety (both of the work and of people) and for this reason the use of security plans’ software is fundamentally important;
final documentation and restoration ‘s monitoring – when everything is completed, you must proceed cataloging and archiving of all the restorations’ documents. To avoid document loss or incorrect cataloging, online solutions are available which allows you to store and carry with you all documents at all times.

Restoration project: what are the contents and deliverables?

A restoration project must include a series of specific contents and deliverables, including:

building’s historical and architectural reports: description of the architectural characteristics, construction techniques and materials used, as well as the transformations undergone over time;
building’s degradation phenomena’s survey and diagnosis: building’s photographic, planimetric and altimetric documentation, as well as identification of degradation’s causes and manifestations;
analysis of conservation issues and needs: assessment of restoration interventions’ priorities and urgencies;
restoration and recovery’s project: elaboration of architectural, structural and projects’ plant, based on the building’s specific needs and current regulations;
time schedule and cost estimate: definition of economic resources’ timing and requirements for restoration interventions’ implementation.

Survey and documentation of degradation phenomena

The degradation phenomena’s survey and documentation are fundamental for building problems’ correct diagnosis as well as for restoration’s planning of interventions. Among the most used survey techniques, we find digital photography, thermography, laser scanner and tomography. These instruments allow to accurately detect and document the manifestations of degradation, such as cracks, detachments, efflorescence and biological colonizations.

San Pietro in Vinculis in Naples is an example of a historic building’s degradation digital survey.

ACCA software carried out this case study in synergy with the Companies Stress, ETT and the Departments of Architecture and Facilities Engineering at University Federico II of Naples.

The project, called BIM ReculT, focused on the restoration of the church of San Pietro in Vinculis in Naples. The digital survey made it possible to identify and document with precision the phenomena of degradation that affected the wall surfaces and interior decorations. Now days its possible to digitize all the elements that characterize the building, thanks to the use of technologies such as the laser scanner, high-resolution photography and HBIM software.

The project includes the structuring and creation of:

objects;
information sheets;
a collaborative platform for shared process management.

The model was managed entirely in a BIM environment based on the documentary data acquired through laser scanning, digital photogrammetry and SLAM.

Historic building Villa Matarazzo in Ercolano, is an example of degradation’s digital survey

Also in the case Villa Matarazzo in Ercolano’s restoration, the digital survey and BIM methodology ‘s application played a fundamental role documenting degradation phenomena as well as in the design of restoration interventions. In such processes, the greatest difficulties lies in holding together a set of information that is diversified and fragmented.

In the case of the study at Villa Matarazzo in Ercolano the possibility of documenting the state of conservation with the use of usBIM.bSDD has been demonstrated. The study was conducted by DIARC – Department of Architecture, University of Naples Federico II and highlighting the application of BIM methodology to historical artifacts (HBIM). Aiming at the management optimization of information data for the purposes of the building’s protection action, enhancement, conservation and recovery.

Restoration of historic buildings: how to organize recovery and restoration of historic buildings?

In order to better organize the recovery and restore of a historic building, it is necessary to follow a multidisciplinary approach involving different skills and professionals, such as architects, engineers, art historians, restorers and geologists. In addition, it is important to consider the following aspects:

objectives of the restorations’ definition: enhancement of cultural heritage, functional recovery, adaptation to regulations, improvement of safety and accessibility conditions, etc.;
intervention phases’ planning: survey and diagnosis, design, implementation, documentation and monitoring;
involvement of competent authorities and local communities: request for necessary authorizations and permits, promoting the participation and support of the communities concerned;
search for funding and incentives: identification of public and private funding sources, submission of projects and requests for contributions.

Restoration interventions: what are they and how to do them?

The restoration of historic buildings can be divided into several categories, including:

structural consolidations’ interventions: aiming to guarantee the stability and safety of the building, through reinforcement works, fixing, injections and structural joints;
architectural restorations’ interventions: concerning the conservation and recovery of wall surfaces, decorations and architectural elements, through cleaning, reintegration, plastering and coating;
restoration of building facilities and infrastructures: replacing or adapting electrical, hydraulic, thermal and air conditioning systems, as well as communication and safety networks;
interventions to restore the landscape and the surrounding environment: consisting of recovery and enhancement of outdoor spaces, gardens and green areas, with maintenance, planting and lighting works.

Restoration of historic buildings’ facades: how to do the projects and interventions?

The historic buildings’ facades restoration, requires particular attention designing and implementing the interventions. This, in order to preserve the aesthetic appearance and original characteristics. Among the main actions to be taken, we can mention:

surveying and analysis of facade’s conditions: documentation of injuries, alterations and pollution patinas, through photographs, drawings and sampling;
choice of restoration techniques and materials: selection of cleaning, consolidation, reintegration and protection methodologies, based on compatibility, reversibility and durability criteria;
restoration interventions’ design: elaboration of executive projects and technical specifications, in collaboration with restoration and conservation experts;
restoration works: the execution of facades restoration’s works, according to project’s indications and good practices. Naturally performed by specialized personnel with adequate equipment.

Technologies and tools used in historic buildings’ restoration

In historic buildings’ restoration, using advanced technologies and tools is essential to ensure quality and interventions’ effectiveness. Some examples of technologies used are:

laser scanner: allows to obtain a high precision three-dimensional survey of buildings and its surfaces;
infrared thermography: to detect thermal anomalies and water infiltrations in wall structures;
electrical tomography: facilitates cavities’ identification, discontinuities and humidity within the masonry;
monitoring and control systems: provides real-time information on building’s conservation condition allowing timely interventions in case of anomalies or dangers.

Restoration’s project final documentation

Once the restoration work has been completed, it is important to draw up a final documentation. This would illustrates the process followed and results obtained. This documentation may include:

final reports: carried out interventions’ detailed description, materials used and techniques adopted;
photographic and graphic documentation: images and drawings capturing the evolution of restorations and comparisons between the initial state before works and the final one;
monitoring report: control systems’ collected data analysis and performances’ evaluation of restoration interventions;
historical and bibliographical archive: collection of documents, publications and bibliographical references relating to the building and restoration.

The role of experts in historic buildings’ restoration

Restoration and conservation experts play a fundamental role in the process of recovering historic buildings. They possess the knowledge and skills necessary to ensure a respectful intervention of the heritage and its peculiarities. Among the professional figures involved, we find architects, engineers, restorers, art historians, geologists and specialized technicians.

Ethical and Legal Considerations in Historic Buildings’ Restoration

The restoration of historic buildings involves a series of ethical and legal considerations. These are linked to the conservation of cultural heritage as well as the heritage protection rights and local communities’ interests. We can mention among the most relevant aspects:

international principles and standards’ compliance: adherence to conventions, recommendations and guidelines of UNESCO, ICOMOS and cultural heritage protection bodies;
competent authorities and institutions’ involvement: require authorisations and permits for restoration interventions and current laws and regulations’ compliance;
safeguarding cultural values and local identities: the search for a balance between the conservation of historical and artistic heritage. As well as the enhancement of cultural and territorial characteristics;
accessibility and public use: guaranteeing adequate access and visitation conditions for all citizens and visitors. Respecting the needs of security, inclusion and sustainability.