Survey the room before choosing products
Record the room dimensions, door and window, drain route, floor buildup, ventilation and electrical points. Ask whether the proposed shower position can be achieved with the existing connection levels. A flush shower is not established merely by purchasing a shallow tray: levels, drainage, structure and waterproofing interfaces must work together.
Keep common stacks and structural alterations outside a casual fit-out instruction. Before disturbing older finishes, discuss investigation: the BAuA asbestos information identifies relevant risks in older construction and later refurbishment layers. A clean-looking tile or adhesive is not evidence that intrusive work is safe. Agree competent investigation rather than DIY sampling or grinding.
Specify the concealed work and interfaces
The waterproofing manufacturer’s technical explanation distinguishes the tile covering from the waterproof layer. Ask the designer and trades to identify exposed surfaces, suitable substrate, connected system, penetrations, drain and doorway detail. Retain photographs and agreed checks before tiling conceals the work. A silicone finish at the edge is not a complete description of the hidden system.
- Who removes and disposes of the old installation?
- Who prepares the base and confirms installation levels?
- Who connects plumbing, electrical fittings and the ventilation system?
- Who supplies and fits the shower enclosure and vanity?
- Which concealed-stage checks and final operating records are included?
Check ventilation against the whole dwelling and actual moisture load with the competent professional. The ventilation planning guidance explains why airtightness and air paths matter. A product labelled “bathroom fan” does not by itself define supply air, exhaust route or the relevant design.
Calculate product quantities separately from room area
For this teaching room, 2 × 3 m gives 6 m² of floor. The perimeter is 10 m; a chosen 2.4 m tiled height gives 24 m² of wall before openings. Subtract a 0.8 × 2 m door and a 1 × 0.6 m window, then add the floor: 27.8 m². This all-wall tiling choice is not a universal specification.
A chosen 10% cutting allowance gives 30.58 m². With 1.5 m² per box, order 21 boxes, or 31.5 m². At invented EUR 40/m² net, supply is EUR 1,260 net. The designer’s waterproofing area is a separate measured quantity; it must not be copied from either the 6 m² floor or the purchased tile area.
Read the complete teaching budget
| Item | Amount |
|---|---|
| Protection and site arrangements | 1 200 |
| Removal and disposal | 2 100 |
| Electrical alterations | 900 |
| Specified ventilation work | 800 |
| Private water and drainage work | 1 200 |
| Sanitary products and their fitting | 2 700 |
| Tile supply: 31.5 m² × EUR 40 | 1 260 |
| Tile laying and grout | 1 000 |
| Substrate preparation | 800 |
| Shower enclosure supplied and fitted | 1 500 |
| Specified waterproofing system and execution | 500 |
| Checks and cleaning | 400 |
| Net package | 14 360 |
| 19% VAT | 2 728.40 |
| Gross package | 17 088.40 |
| Item | Amount |
|---|---|
| Gross bathroom package | 17 088.40 |
| Professional survey and coordination | 1 071 |
| Temporary living | 900 |
| Identified unresolved-work allowance | 1 190 |
| Chosen 10% reserve on gross package | 1 708.84 |
| Full funding | 21 958.24 |
The reserve covers remaining risk, while EUR 1,190 is attached to a named unanswered task. The package does not become complete simply because its total has a tax line. VAT treatment and all exclusions still have to match the actual supplier and scope.
Compare variations before ordering
If the same 31.5 m² tile purchase rises from EUR 40 to EUR 50/m² net, add EUR 315 net, or EUR 374.85 gross under the assumption above. Taking it from reserve leaves EUR 1,333.99 and preserves funding; retaining the original reserve raises funding to EUR 22,333.09. Do not add the entire replacement tile purchase on top of the old one.
Ask bidders to clarify provisional substrate repairs, concealed damage and excluded products. The consumer commissioning guidance favours detailed inclusions. A fixed price for a defined bathroom does not automatically include a later request to move the shower. Record the revised work, gross price and programme before it changes the order.
Plan the outage and handover
- Confirm access to another usable bathroom during the works.
- Agree removal, services, waterproofing, finishes and fitting as dependent stages.
- Use professional release criteria for drying and testing rather than invented fixed days.
- Check operation, water routes, ventilation and agreed finish quality.
- Record defects, product documents and the reconciled account.
Keep the work package and separate owner costs visible in Reno Pro. Review the final figure as a finished, usable bathroom and the cash needed to reach it. Cosmetic completion does not replace the technical records for work that is now hidden.
Sources, date and scope
- Verbraucherzentrale — Handwerker: Auftrag, Abnahme und Rechnung
- Schlüter-Systems — Abdichtung von Innenräumen — DIN 18534
- Verbraucherzentrale — Planung einer Lüftungsanlage
- Bundesanstalt für Arbeitsschutz und Arbeitsmedizin — Informationsportal Asbest — FAQ
- Bundesministerium der Justiz / Bundesamt für Justiz — UStG § 12 — Steuersätze
Checked on 19 October 2026. Local examples concern Berlin unless stated otherwise. Check state law, heritage protection, community rules and actual work for the specific project. Teaching figures are invented euro amounts, not market prices or offers. The article projects are independent. Tax and funding calculations apply only under the stated assumptions; competent professionals resolve project-specific technical and legal questions.