The framework law on noise pollution: it sets principles, competences (State, Regions, Municipalities) and instruments to govern noise. From it descend the acoustic classification of the territory, the limit values and the acoustic requirements of buildings. For design it introduces two key assessments: acoustic impact and acoustic climate.
It concerns fixed and mobile sound sources, the acoustic planning of the territory and the requirements of buildings. The limit values are set by D.P.C.M. 14/11/1997 and the passive acoustic requirements by D.P.C.M. 5/12/1997; Regions and Municipalities handle implementation and controls.
Law 447/1995 is the framework law on noise pollution: it defines principles, competences (State, Regions, Municipalities) and the instruments to govern noise as an environmental and health factor. From it descend the implementing decrees on limits, building requirements and the qualified figures.
The Municipality divides the territory into six acoustic classes, from Class I (particularly protected areas: hospitals, schools) to Class VI (exclusively industrial areas), each with its own day and night noise limits. The zoning is the precondition: without it, you do not know which limit applies.
Two assessments that are often confused. The acoustic impact documentation concerns whoever introduces a noise source (an activity, an infrastructure): it shows it will not exceed the limits towards the outside. The acoustic climate assessment concerns whoever inserts a sensitive receiver (schools, hospitals, dwellings) near existing sources: it shows the site is quiet enough for that use. The first looks from the work outwards; the second from the environment towards the work.
| Assessment | When it is needed |
|---|---|
| Acoustic impact | new noise sources (activities, infrastructure) |
| Acoustic climate | new sensitive receivers (schools, hospitals, dwellings) near sources |
Beyond the absolute zone limits, inside living spaces the differential criterion applies: the difference between ambient noise (with the source active) and residual noise (without it) must not exceed strict thresholds, stricter at night. It is the criterion behind most neighbour disputes; it does not apply below certain noise levels, considered negligible.
The law establishes the qualified acoustics technician, entitled to sign the assessments, and assigns the zoning and controls to the Municipalities, coordination to the Regions and the general criteria to the State. The passive acoustic requirements of buildings — facade insulation, between units, against footstep and systems noise — are set by D.P.C.M. 5/12/1997.
Noise is the most underestimated and most litigated form of pollution. Law 447/1995 makes it a design parameter: acoustics is not a finishing touch but a performance, proven before (climate/impact) and built afterwards (passive requirements). For premium architecture, silence is a material.
The acoustic impact concerns whoever introduces a noise source (showing it will not exceed the limits outward); the acoustic climate concerns whoever inserts a sensitive receiver near sources (showing the site is quiet enough).
The division of the territory into six classes (I-VI), from particularly protected areas to industrial ones, each with day and night noise limits.
Inside living spaces, the difference between noise with the source active and without it must not exceed strict thresholds (stricter at night); it adds to the absolute limits and does not apply below negligible levels.
The qualified acoustics technician, an authorised figure listed in the national register.
In D.P.C.M. 5/12/1997, the implementing decree of the framework law, which sets facade insulation and insulation between dwellings, from footsteps and from systems.
Transitional limits apply until the classification is approved; but the zoning remains the correct reference for knowing which limits apply.