As an indicative guide, most attic conversions in Ireland fall somewhere between €25,000 and €75,000. Where you land inside that range depends mainly on the type of conversion, the size and layout of your roof, and how much you fit out the finished room.
The type of conversion is the biggest single factor. A simple Velux or rooflight conversion that works within your existing roof shape is the most affordable, roughly €18,000 to €30,000. A dormer conversion, which builds out a box to add headroom and floor space, is typically €30,000 to €50,000. A hip-to-gable conversion tends to run €40,000 to €70,000, and a mansard, which reshapes a large part of the roof, is usually €45,000 to €90,000.
On top of the base build, the finish matters. Adding an en-suite bathroom commonly adds around €8,000 to €15,000. Other cost drivers include relocating a water tank, upgrading the staircase, structural steel, electrical and heating work, and the standard of flooring, joinery and glazing you choose.
These are ranges, not quotes. The only reliable way to know your figure is a site visit, because roof pitch, existing structure and access all change the sums. You can get a ballpark from our cost calculator, read the full attic conversion cost guide, or arrange a free assessment for a proper estimate on your own home.