Cost · Detail
Hidden costs of a dormer
A low headline price often hides the lines a quote left out. These are the items that most often turn up on the final invoice — and the ones to bring up before you sign anything.
6 min leestijd·Onafhankelijke informatie
Short answer
The most common hidden costs are crane hire, street-occupation permits, lead and flashing upgrades, interior finishing, electrical work and disposal. They are rarely dishonest — usually just left out because the company has not seen your house yet. The fix is to ask for them on paper before the contract is signed.
The most common hidden costs
- Crane and transport. A prefab dormer needs a crane. If access is tight, a bigger crane and a street closure follow.
- Street-occupation permit. If the crane stands on a public road, the council charges for the day.
- Lead and flashing upgrades. Heavier-code lead, lead replacement strips and corner detailing are often quoted as "standard" and then upgraded later.
- Interior finish. Plasterboard is in, but painting, skirting, mouldings and decoration are usually out.
- Electrical work. Sockets, light points or moving a smoke alarm in the new space are rarely in a dormer quote.
- Window dressings. Roller blinds, shutters or curtain rails almost never sit in a dormer quote.
- Disposal. Old tiles, broken battens and roofing felt have to go to a waste site. Some companies include this, many do not.
- Asbestos check. Houses built before 1994 may have asbestos in the existing roof construction; a survey may be needed before work begins.
Typical impact on the final bill
| Item | Typical add-on | Who usually pays |
|---|---|---|
| Crane and transport | €400 – €1,200 | Homeowner if not included |
| Street-occupation permit | €50 – €250 | Homeowner via council |
| Upgraded lead work | €150 – €600 | Homeowner |
| Interior painting and finish | €500 – €1,500 | Homeowner |
| Electrical points | €200 – €700 | Homeowner |
| Disposal and skip | €150 – €400 | Sometimes included |
| Asbestos survey (pre-1994 homes) | €300 – €600 | Homeowner |
How to spot them in a quote
FAQ
FAQ
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01Which hidden costs are most common?
Crane hire, street-occupation permits, lead and flashing upgrades, interior plastering and painting, and disposal of old materials. Together they can add €1,000–€3,000 to a quote that looked complete.
02Should the permit fee be inside the quote?
Yes, ideally. Companies that handle the permit end-to-end should state both their fee and the council fee, so you are not surprised on invoice day.
03Why is crane hire sometimes excluded?
Because the supplier cannot confirm the access route until after the site visit. That is fair, but the quote should still state a clear estimate or a worst-case figure.
Conclusie
Hidden costs are rarely a trap on purpose. They are usually the result of a quote written quickly to win the job. A clear, itemised quote that names every potential extra is worth a little more than a tight one that leaves the surprises for invoice day.