Building a Mezzanine: is it a Renovation or Free Building Intervention?

When deciding to renovate an apartment, a mezzanine is an excellent solution to increase the floor space in your home. A mezzanine allows us to create new, highly functional spaces: a new bedroom, a small study, a storage room, and more. There are different types of mezzanines, depending on their purpose and construction methods. Regulations also vary from region to region, depending on the project you intend to undertake. Can a mezzanine be built as a free building intervention or as a renovation work? Let’s examine the differences in detail.

What is a Mezzanine?

A mezzanine is additional space created in a property by adding a new floor slab. The technical definition of a mezzanine was included in Annex A of the Standard Building Regulations related to the Prime Ministerial Decree of October 20, 2016.A mezzanine is defined as a “Practicable horizontal internal partition, obtained through the partial interposition of a horizontal load-bearing structure in an enclosed space“. Building a mezzanine therefore means adding a floor slab within a volume that is open on at least one side, towards an internal space known as “double volume“. Usually, the new elevated space is separated from the rest of the environment with low walls or railings.

A mezzanine can be built in two ways, depending on its structural characteristics:

1. Self-supporting autonomous structure:
   when it is built as a large independent structure, generally in steel, that transfers loads to the ground through additional foundations.
2. Collaborative structure connected to the building’s existing structure:
   when it is built by adding a floor slab through beams to the load-bearing walls. To build this type of mezzanine, it is necessary to examine the structure and seismic properties of the space being modified, complying with all bureaucratic requirements indicated by regional technical offices.

Different Uses of a Mezzanine

Beyond structural considerations, it’s also necessary to carefully evaluate the intended use of a mezzanine. It must comply with specific parameters according to the different uses recognized by Italian law, namely:

• Habitability and usability by people
• Accessory habitable use, not accessible to people
• Production use, intended for goods storage and staff presence.

Mezzanine: Free Building Work or Renovation?

Based on the use, the administrative procedures for building a mezzanine also change. If a mezzanine is habitable, it must meet precise standards and its construction cannot be unrestricted.
According to Ministerial Decree of July 5, 1975, for a dwelling to be habitable, it must have a minimum height of 2.70 m for living spaces, and 2.40 m for accessory spaces such as corridors, bathrooms, storage rooms, and various passageways. These requirements must also be met in the spaces above and below a mezzanine if it is intended for residential use. All necessary permits for structural intervention must be obtained.

If the mezzanine has an accessory use and is not intended for human occupancy, the procedures might be different. If the mezzanine is strictly a storage room, meaning an enclosed space without light points and windows, a building permit might not be necessary. However, this does not mean the work falls under free building. If you’re building a floor slab, you still need to file a Certified Notice of Commencement of Works, a Certified Communication of Commencement of Works (CILA) is not sufficient. If you’re increasing the property’s floor space, CILA is not enough.

Council of State Ruling No. 3155/2022

Recently, the Council of State ruled on this matter with decision no. 3155/2022, regarding a municipal administration’s demolition order for an unauthorized mezzanine.

According to the constitutional body, conservative restoration interventions are those aimed at ensuring functionality through a set of works that respect the formal, typological, and structural elements of the property, allowing compatible uses with it. Building renovation interventions also include those that, while maintaining the existing volume of the property, aim at partial or total transformation of the building structure.
However, interventions related to mezzanines in residential properties that involve less than 50% of the floor slab of the room in question, and less than 40% of the entire apartment, do not fall within the scope of building renovation.

In Conclusion?

To determine the feasibility of the project and what type of mezzanine to build, it is necessary to consult an expert technician who can make a precise assessment of the property’s structure to be modified. It is essential to carefully consider the municipal and regional regulations of the specific location where the property is situated. For mezzanine construction, Italian regulations vary significantly not only from region to region but also from municipality to municipality.Are you thinking about renovating an apartment, taking advantage of the available tax bonuses, and would like to build a mezzanine? Don’t hesitate to contact us, our technicians will answer all your questions.