Quotes vary widely because they often are not comparing the same thing. One quote may include work and materials that another leaves out, so a lower number is not always the better deal. The best way to compare is to check exactly what each quote covers, item by item.
Common reasons two quotes for the same attic differ:
- Scope: one may include the staircase, structural steel, moving the water tank, plumbing or electrics, while another treats these as extras.
- Specification: the standard of insulation, glazing, flooring, doors and joinery makes a real difference to price.
- Compliance and certification: proper fire safety, insulation to standard and any required certification cost money and should be in the quote.
- En-suite or not: adding a bathroom typically adds €8,000 to €15,000, so a quote without one will look cheaper. See our en-suite cost guide.
- Provisional sums: some quotes use estimates for items not yet decided, which can rise later.
- VAT: check whether the price includes VAT, and that the contractor is VAT-registered.
A very low quote sometimes means work has been left out that you will have to pay for later, or that the specification is lower than you expected. A higher quote can genuinely reflect more inclusions and a better finish.
Ask every contractor for a written, itemised breakdown so you are comparing like with like. Our main cost guide explains the typical inclusions, and a free assessment gives you a clear, itemised estimate for your own house.