The Certificate of Static Suitability (CIS) is an essential document certifying the structural stability of a building. It is issued after a careful technical analysis and is required in various circumstances, such as a request for a certificate of habitability or the commencement of renovation work for mutual agreement between the parties. Recently confirmed (ruling 1120/2024 of the Tuscany Regional Administrative Court), the CIS is mandatory for obtaining building amnesty in seismic areas.
The certificate of static suitability (CIS) is also required for buildings located in the Municipality of Milan , where they are more than 50 years old, as detailed below.
CIS: Verification process and control levels
CIS certification in Milan is primarily based on two-level audits, depending on the complexity and need for more in-depth investigations.
Level 1: Initial Analysis
This initial phase consists of a general assessment of the building , based on documentation and visual inspection.
At this stage, the historical reconstruction of the documentation pertaining to the structural works project is of fundamental importance. Likewise, all subsequent construction/structural practices that may have led to modifications to the original structural system and, in some cases, may have introduced impairments to the structural framework itself will also be investigated. In addition to the above, with a view that extends beyond the structural works alone, it is essential to reconstruct interventions that are not explicitly structural , if they interact, even partially, with structural elements and significantly reduce their capacity and/or modify their rigidity.
It is also clear that following the operations described above, it is equally essential to conduct accurate and thorough inspections —both internal and external—to identify any anomalies resulting in a significant reduction in the resistant and/or deformation capacity of the structure or some of its components due to: significant degradation and deterioration of the mechanical characteristics of the materials; significant deformations resulting from foundation problems; damage caused by environmental factors (earthquakes, wind, snow, and temperature), exceptional events (impacts, fires, explosions), or abnormal operating and usage conditions;
The main activities required to prepare the certificate of static suitability (CIS) for buildings in Milan over fifty years old can be summarized here:
Activity:
Search for project/test documentation with critical analysis of what is found.
Research into building practices that occurred following the completion of structural works in order to assess any interventions that may have impaired the same works.
Historical reconstruction of exceptional events that may have undermined the building's stability.
Definition of the structural organism resistant to loads (governed and non-governed by man).
Check that the loads are consistent with the intended use of the premises.
Interaction with external factors independent of the building.
Visual inspection of the structure to identify any signs of deterioration or anomalies including:
foundation settlements and deformation patterns of elevation works;
structural degradation phenomena;
crack patterns even in non-structural infill walls;
Assessment of the need for further investigation.
Advancement to the next level: This is necessary when there are doubts about the building's stability or signs of deterioration and/or collapse; substantial modifications have occurred that have altered its structural performance; or changes in intended use have occurred, resulting in increased loads, without appropriate static assessments. While awaiting completion of Level 2, it is also advisable to evaluate the partial or total limitation of the building's use.
Level 2: Detailed investigations
When the initial analysis for static suitability highlights critical issues as indicated above, we move on to a more in-depth level which consists of the safety assessment in the manner defined in paragraph 8.3 of the Ministerial Decree of 17-01-2018 (NTC 2018).
The NTC 2018 standard is the first regulatory instrument that regulates in detail the safety assessment of an existing structure through a quantitative procedure , aimed at determining the extent of the actions that the structure is able to sustain with the minimum safety level required by this regulation.
The standard also includes the cases in which a safety assessment is mandatory . It also provides guidance on increasing the level of safety by addressing the overall structural design with interventions, including local interventions, as well as adopting restrictive measures on the use of the building and/or proceeding with improvement or adaptation interventions if the checks relating to human-controlled actions, i.e., primarily permanent loads and other service actions, are not met.
We believe it is of fundamental importance to draft a technical document —referred to in Section 8.5 of the Ministerial Decree of January 17, 2018— as a preliminary step to the safety assessment . The document must provide a highly detailed historical and critical analysis, a thorough survey, a mechanical characterization of the materials, the definition of knowledge levels and confidence factors, and a detailed assessment of the applicable actions. For these aspects, the relevant circular—although not binding—also provides essential guidance to the technician responsible for drafting the aforementioned technical document.
Certificate of Static Suitability (CIS): the figures involved in the process
The release of the CIS involves several actors, each with a specific role.
Who needs to obtain the CIS?
The subjects who are required to obtain the static suitability certificate are:
Property owners : must ensure the safety of their building, whether for private use or for commercial or other uses.
Condominium administrators : they are responsible for managing the safety of residential buildings.
Who issues the CIS?
The analysis and issuance of the static suitability certificate are handled by specialized professionals. The document must be prepared by a qualified professional, such as an architect or civil/construction engineer. No specific seniority in the professional register is required for its preparation, unlike the static testing .
Why is CIS necessary?
There are many reasons why a certificate of static suitability is required:
Regulatory compliance : obligation to comply with structural safety provisions.
Buying, selling and renting : In some areas, the CIS is useful for selling or renting properties.
Habitability certificate of a property: it is often required to obtain the habitability certificate of a property, in particular when a static test certificate issued pursuant to Law 1086/71 is not available.
Verification of conformity or building amnesties : this is necessary, for example, in situations of requests for building amnesty according to Law 47/85 .
Renovation work : before starting even minor interventions, it is advisable to check the stability of the building.
Protecting public safety : to prevent structural collapses or failures that could put people and property at risk.
Insurance valuations : a tool used in certain cases by companies to define premiums and coverage.
Adaptation and improvement : essential to identify any structural deficiencies.
AS Ingegneria: excellence in building safety and conservation
The Certificate of Static Suitability (CIS) is a crucial document for ensuring building safety and compliance with regulations. Approaching the certification process with awareness, understanding the required checks and the stakeholders involved, allows for better management of structural safety , both from a technical and regulatory perspective.
Each Certificate of Static Suitability project undertaken by AS Ingegneria represents a unique challenge, tailored to the specific characteristics of the buildings analyzed. Our experience is reflected in a wide range of projects on residential, commercial, and historic buildings.
We drafted the CIS for Villa Mirabello , a prestigious 15th-century historic building in Milan , ensuring its preservation and regulatory compliance. In the sports sector, we also worked on the Saini Sports Center in Milan, where the structural suitability assessment allowed us to certify the safety of the facilities serving the facility. For the Pirotta school complex in Desio , our team conducted targeted consolidation interventions, essential for the building's safety and compliance with regulations.
In the commercial and residential sectors, our work has involved major buildings such as those at Piazza del Liberty 2 and 4 in Milan, as well as the Centro Lido Rotonda , for which we performed in-depth structural assessments, ensuring compliance and usability of the spaces. Each project was carried out with a tailored approach, based on advanced technologies and targeted diagnostic strategies.
Protecting Italy's architectural heritage requires expertise, methods, and cutting-edge tools. AS Ingegneria continues to apply its expertise to historic, educational, sports, and commercial buildings, ensuring safety, compliance, and durability for the future.
For more information on preparing the Certificate of Static Suitability (CIS) in Milan , you can contact our experts .
