Declaration of conformity (D.M. 37/08): what to attach and what to check

#The mandatory attachments (annex I)

1. Project under articles 5 and 7 (note 4).
2. Report on the types of materials used (art. 7 c. 1; note 5).
3. Schema of the installation as built (note 6) — or a reference to the project, if a professional drew it.
4. Reference to previous or partial declarations already existing (note 7; art. 7 c. 3 and 6): needed for transformation, extension and extraordinary maintenance; not applicable to a new installation with nothing to cite. Each earlier declaration is cited with the firm and the date.
5. Copy of the certificate of technical-professional requirements (the visura; arts. 3–4).

Optional, but the DiCo is issued after the tests: the test report (art. 7 c. 1; note 8).

#When the project must be a professional's (art. 5)

A project is needed for new installation, transformation and extension; for extraordinary maintenance the as-built schema is enough; ordinary maintenance needs neither project nor declaration (art. 10 c. 1).

A professional on the albo is required (art. 5 c. 2), for electrical installations, notably for:

• condominium common parts;
• a dwelling over 6 kW or over 400 m²;
• non-domestic premises (production, commerce, tertiary, other uses) over 6 kW, over 200 m² or supplied over 1,000 V;
• medical rooms, explosion-hazard places, higher-fire-risk rooms; lightning protection on buildings over 200 m³.

Otherwise the firm's technical manager's project is enough: at least the installation's schema. A "professional's" project only counts if it carries the albo registration details.

#The firm's qualification (arts. 1 and 3)

Only a firm qualified for the work's letter can declare it: a) electrical installations, lightning protection, door and gate automation; b) radio-TV, antennas and electronics — data network, CCTV, intruder alarm, intercom. Photovoltaics, EV charging and lighting are letter a. The letters are read from the visura, never inferred from the kind of work.

#Materials: CE marking

Every material in the report must bear CE marking (Directive 2014/35/EU). A material without CE is replaced, or the maker's EU declaration of conformity is attached. Recording the product standard helps too.

#The tests: row by row, not the overall outcome

A report saying «positive» is not enough: each reading is checked against its limit (CEI 64-8 Part 6), for example:

• insulation resistance: at least 1 MΩ at 500 V for circuits up to 500 V (0.5 MΩ at 250 V for SELV/PELV);
• earthing (TT system): R_A × I_Δn ≤ 50 V (25 V in medical rooms, building sites and agricultural premises);
• RCDs: tripping within 300 ms at I_Δn (type S between 130 and 500 ms), and between ½ I_Δn and I_Δn.

A reading outside its limit rules out declaring «tested with a positive outcome». In the recorded example the report says «positive», but the bathroom reads 0.38 MΩ at 500 V against the 1 MΩ minimum.

#After signing

• The signed declaration, with its mandatory attachments, is handed to the client.
• For buildings already agibili it is deposited with the SUE within 30 days of the end of works (art. 11 c. 1); for a building not yet agibile it goes with the certified agibilità notice.
• In a workplace, the employer sends the earthing declaration to INAIL within 30 days of commissioning (D.P.R. 462/01).

#How the agent does it

The Declaration of conformity D.M. 37/08 agent reads the job's documents — visura, job sheet, project or schema, the materials list in Excel or CSV, job reports, test report, the previous DiCo — and prepares the draft on the ministerial model with its attachments. Thresholds, letters, test limits and dates are checked by code; what is missing becomes a gap with its rule and what to do, and a missing value stays «[da completare]», never invented. The verdict on top: «Pronta da firmare» or «Mancano N cose». You sign and send.