Institutional portal - Municipality of Milan

The art. 1, paragraph 2 of Regional Law 7 of 10 March 2017, defines basements as rooms and rooms located on a floor with the floor at a lower level, even if only partially, than the ground adjacent to the building and the ceiling which is located, even only partially, at a higher level than the ground adjacent to the building.

These rooms and rooms can be recovered provided that they were built on the date of entry into force of the law and that they are located in buildings served by primary urbanization works.

Without prejudice to compliance with the hygienic-sanitary requirements, the recovery of basement rooms and rooms is always permitted even in derogation of the building limits and requirements of the PGT and building regulations. The internal height of the rooms intended for the stay of people must not be less than 2,40 metres, without prejudice to the minimum heights required by law for specific intended uses of the rooms and rooms (e.g. for residences, minimum height 2,70 .XNUMX m.) and without prejudice to the regulations in force regarding the environment and landscape.

For the purposes of containing energy consumption, the recovery must include suitable thermal insulation works in compliance with the relevant technical requirements contained in the national and regional standards and regulations in force.

If the recovery of the basement rooms involves the creation of autonomous units for residential use, the municipalities send a copy of the certified report presented pursuant to Article 24 of the Presidential Decree to the territorially competent Health Protection Agencies (ATS). 380/2001, which must be accompanied by a certificate of compliance with the exposure limits to radon gas established by the building regulations. 

The underground walls must be protected by ventilated cavities or with other equally effective technical solutions.

The presence of a suitable ventilated crawl space over the entire surface of the rooms or another equally effective technical solution must be guaranteed.

For recovery for residential use intended as an extension of an existing residential unit and only for ancillary or service rooms, the use of totally artificial air lighting is always permitted as long as the recovered part does not exceed 50 percent of the total useful surface area of ​​the unit.

For recovery for residential use intended as the creation of autonomous units, the achievement of the air lighting indices with technological systems cannot exceed 50 percent compared to what is required by local regulations.

For recovery for residential use, to calculate the air-lighting ratios, the distance between the lights of the room and the adjacent building must be at least 2,5 metres.

Only after ten years have elapsed following the achievement of usability can the volumes of the recovered basement rooms and rooms change their intended use.

For further information, consult the reference legislation referred to.