What should an Italian preventivo include for a 5 m² bathroom?

Specify the room you are actually buying

Decide whether this is a surface refresh or a renewal of the room’s installations. Retaining the WC position does not prove that the hidden drain is suitable. Ask the contractor to inspect accessible connections, establish the proposed levels and identify which existing pipes and electrical circuits will remain.

List the WC, basin, bath or shower, taps, screen, storage and accessories with models or a defined supply allowance. Record finished dimensions and door movement. In a compact room, an outward measurement on a product catalogue is less useful than the clear space after the screen, basin and towel radiator have been installed.

Measure the walls and the layers

For a rectangular 2 × 2.5 m room, the perimeter is 9 m. Tiling walls to 2.2 m gives 19.8 m² before openings. Deducting a 0.8 × 2 m doorway and a 1 × 0.6 m window gives 17.6 m²; adding the 5 m² floor gives 22.6 m². Agree the measurement rule in the quote rather than assuming every contractor deducts openings in the same way.

A chosen 10% purchase allowance brings the tile order to 24.86 m². Packs covering 1.44 m² require rounding up to 18 packs, or 25.92 m². This is a cutting and packing example, not a universal waste percentage. Separate tile supply from labour and include substrate repairs, waterproofing junctions, corners, trims and the agreed treatment around the drain.

Read a complete example budget

The €600 outside allowance is provisional and is not a comune tariff. The agency guide on IVA explains why reduced taxation is not determined by the bathroom’s size. Direct purchases and significant-goods calculations can change the invoice split. Ask for the final gross total before accepting the offer. In a separate IVA illustration, a qualifying €9,000 net maintenance contract contains €5,500 of significant goods and €3,500 of other value. The assumed 10% base is €7,000 and the 22% base €2,000: IVA is €1,140 and the gross total €10,140. This is not the bathroom budget above.

Identify the work that must be checked before covering

Ask the installer to state how the substrate, waterproofing and pipework will be inspected before tiles or furniture conceal them. Agree who records the check and how a failed result is put right. A photograph of a finished wall cannot establish how its concealed junction was built.

For installations within scope, DM 37/2008 article 5 provides the design framework and article 7 concerns checks and the declaration of conformity. Partial renewal refers to the renewed portion while taking account of the existing system’s safety and compatibility. Ask which documents will cover the bathroom, which parts remain old and what further work the installer considers necessary. A generic whole-flat certificate should not be promised for unrelated untouched work.

Check procedure and practical access before the order

The category depends on the intervention under DPR 380 article 3, not on the phrase “bathroom package”. The tecnico must check whether the actual work falls within free activity, CILA or another route, together with local sanitary, structural and protection rules. Moving a drain into a shared stack requires a separate review of the common system and building arrangements.

Agree water shutdowns, permitted working times, lift protection and the carrying route. Establish how long the flat will lack its only WC or washing facility. Include any temporary arrangements in the funding plan. Request a sequence that respects the selected materials’ curing and commissioning instructions, rather than relying on a headline completion time.

Manage selections and handover

If the included net tile allowance of €650 changes to an agreed €850 with all other work unchanged, the increase is €220 at the example’s assumed 10% IVA. Using reserve leaves €935; preserving reserve raises funding from €13,305 to €13,525. Specify the approved product before ordering and deduct any replaced allowance before adding the new selection.

1. Compare the finished layout with the agreed drawing.
2. Ask the contractor to demonstrate drainage, fittings, screen operation and the agreed installation checks.
3. Inspect accessible junctions, tile edges, falls where specified and door clearances with the responsible professional.
4. Obtain the invoice, product instructions and applicable DiCo with its attachments.
5. Record defects, unfinished work, the responsible party and a date for correction.

Keep the quote and changes beside the recorded costs and payments in Reno Pro. A complete bathroom offer describes the hidden work, usable room and handover, so that a low initial price cannot conceal the most important tasks.

Sources, date and scope

• Normattiva — DPR 380/2001, art. 3
• Normattiva — DPR 380/2001, art. 6 bis
• Gazzetta Ufficiale — DM 37/2008, art. 5 — progettazione degli impianti
• Gazzetta Ufficiale — DM 37/2008, art. 7 — dichiarazione di conformità
• Agenzia delle Entrate — Ristrutturazioni edilizie: le agevolazioni fiscali, febbraio 2026 — copia PDF

Checked on 19 October 2026. Examples concern a flat in Milan unless stated otherwise; check the actual work against the rules of your comune and region. Teaching figures are invented to explain the accounting, not market averages or an offer. Appropriate professionals establish tax eligibility, technical suitability and required filings. Where used, the February 2026 Agenzia delle Entrate guide is linked as a copy of the agency-authored document.