The declaration of conformity of home systems: definition, when required, obligations, penalties

The Ministerial Decree 37/2008, evolution of the Law 46/90, governs the construction, maintenance, and design of systems in buildings. The declaration of conformity of the systems is a document issued by a company authorized following the installation or modification of a plant. If the "compliance" is non-existent it is possible to proceed with the DIRI (declaration of conformity). The decree describes the obligations and penalties for the owner deeds and renovations.

Declaration of Conformity

At the end of the work, the official of the company that has changed or installed the system, issue the customer the declaration of conformity. This document is composed by the report of the materials used, the forms attached in the decree and the design drawings (if applicable).

In the event that the 'intervention modify an existing installation, the certificate relates only partly modified but must also take into account the functionality and security of all del'impianto.

The declaration of conformity is drawn up the necessary certificate of occupancy to be submitted at the counter only building within 30 days of the end of the work. The municipal office will send the documentation relating to plant the Chamber of Commerce, a body responsible for the checks.

The certificate of conformity of the installations:

- And 'necessary to establish new utilities (gas, electricity, water)

- And 'necessary to obtain the certificate of occupancy

- It is no longer necessary to attach to the deed (but you should specify if the plant is "under")

In order to obtain the certificate of occupancy can contact us and verify the correctness and validity of the declaration of conformity

Declaration of Conformity DIRI

In the case of the certificate of conformity is no longer available, you can replace it with a Declaration of Conformity called "DIRI" (facsimile Diri) only if the plants were established before the entry into force of Decree 37/08. The statement is made by a qualified technician as a plant engineer or technical manager of an enterprise enabled exercising for at least 5 years. The declaration must be supported by assessments and surveys useful to verify the compliance of the installation with the legislation.

When a plant can be considered a norm?

The decree does not require to adapt the non-compliant plants but discipline interventions on existing plants and construction of new ones. To consider an installation in accordance need to define what epoch was made or modified.

If the premises have been made before the 'entry into force of Decree 37/2008 (March 27, 2008) are considered according to whether, when they were made, responding to the existing provisions at that time. If you no longer available the certificate of conformity is possible to replace it with the Declaration of Compliance prepared by an authorized installation engineer with experience in the field for at least 5 years.

In particular, an electrical system made before March 13, 1990 is considered to be under if equipped with isolation and protection against overcurrent places to 'origin and plant protection with GFCI.

Want to know if your facility in accordance with? You are going to rent your apartment and you want to check the regularity and safety of the plants? Contact us for advice.

Obligations in the event of sale, deed and sale of properties

The legislation before the amendment made by the Legislative Decree 112/08, provided that, at the time of transfer of 'property, it was mandatory to download the documentation for the compliance of the plants (or declaration of compliance) and the instructions for use and maintenance to new owner. Also planned was a "guarantee clause" in which the former owner took upon himself the responsibility for the functionality and security of the facilities.

Currently these obligations (included in 'Article 13 of Decree 37/08) were repealed by art. 35 of Legislative Decree 112/08. The provisions were valid for only three months from 27/3/2008 to 25/6/2008.

In the deed the buyer and seller are not obliged to declare conformity or the "non-compliance" of the plants and the certificate is a mandatory attachment. However, in order to avoid disputes by the purchaser in the act is preferable to specify the state of the plants and their compliance with the rules.

Obligations of the customer or the owner of the property

The owner of a building (including a housing unit) that needs an intervention on the plants has the obligation to entrust the task to a 'company authorized pursuant to Decree 37/08 and registered with the Chamber of Commerce.

Following the completion of the work, the owner has the responsibility to maintain the efficiency of the system as outlined in the instructions for use and maintenance issued by the company. The latter remains comunqueresponsabile the safety and functionality of what has installed or created.

Within 30 days dall'allaccio of water, gas or light the owner must provide for the distributor copy of the declaration of conformity or a declaration of compliance.

The obligation is also valid in case of change of the heat capacity of the gas or electrical power (6 kW in the case of property for residential purposes.) In case of non-delivery, the utility suspends the supply.

Plant design

L 'art. 5 governs the design of the systems designer as defining "a professional entitled to practice in accordance with the specific expertise." The project shall be presented at the one-stop shop construction and must be made according to the "rule of art" and in compliance with CEI, UNI or other standardization bodies. The project must contain at least one technical report, drawings and planimetric diagrams of the system.

The project should be performed in the following cases:

- Electrical installations in residential real estate units if more than 400sqm

- Electrical installations in residential units with a capacity greater than 6 kw

- Electrical properties used in trade, manufacturing and service sector activity if it is operated with a voltage greater than 1000V

- Electrical properties used in trade, production activities or tertiary higher power 6kw

- Electrical properties used in trade, manufacturing and service sector activities with larger surface area of 200sqm

- Locations subject to CEI or in rooms used for medical purposes

- Air conditioning with reeds collective branched

- Air-conditioning systems with a cooling capacity of 40,000 refrigeration units / hour

- Units gas pipes with collective branched

- Units gas with heat input exceeding 50 kW

- Plant fire if placed in an activity that requires the ICC Fire Prevention Certificate

The electrical systems established before the entry into force of Law 46/90 (13 March 1990) is deemed to be appropriate if:

- With isolation and protection against overcurrent placed at the origin of the system

- Be provided with protection against direct contact

- Be provided with protection against indirect contact and earth leakage circuit breaker protection

The Ministerial Decree 37/2008


The DM 37/08 pursues public safety and the safety of people in particular to avoid accidents in the home. The regulation repealing certain laws and the Law 46/90 until 2008 was the legal basis for the design and installation of systems implementing the European directives. The decree applies to installations that serve the buildings regardless of the intended use.


The decree 37/08 does not regulate systems that are affected by specific European legislation and, in the case of distribution networks, applies from the point of delivery of the supply. The classification of plants is the following:

- Electricity

- Radio and television

- Air conditioning and ventilation

- Water and sanitary

- Gas

- Lift (lifts, elevators, etc.)

- Fire


Are those who can intervene to modify or install the implants. To obtain a license you need to be registered in the commercial register or the trades and be in possession of the technical and professional requirements. The importance of 'recognition is due to the fact that the person who commissioned the work on the installation is directly responsible for the choice of the company.

To obtain a license, and its "certificate of recognition" is necessary for the technical manager or sole possess specific technical and professional requirements (Article 4) which consist of specific studies or experience in the field.


The sanctions of the Decree 37/08 are applied mainly by the Chamber of Commerce, which also has the function to annotate the failures of the installer companies and have them suspended in case there three times. Even the designers and testers may be subject to measures disciplinatori by Orders of belonging to infringements of the rules.



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