What affects the cost of an attic conversion?

Short answer: there is no dependable national price without a property assessment and a written scope. Roof alterations, structural work, stairs, the intended room use, services, finish, access and professional requirements can each move a contractor's price substantially.

Why we do not publish an average price

You will find plenty of Irish attic-conversion price guides. Read a few and you will notice the ranges do not agree, and that most are published by firms that also sell the work.

That is not necessarily dishonesty — it is that they describe different jobs. One page's figure may be a rooflight conversion on a standard semi-detached house excluding VAT and professional fees; another's may be a dormer with an ensuite on a detached home including everything. Averaging them produces a number that describes nobody's project.

We would rather tell you which questions change the price than give you a figure that sounds authoritative and turns out to be wrong by many thousands of euro.

The details that move a quote

1. Roof changes: working inside the existing roof is a fundamentally different project from adding a dormer or changing a hipped roof to a gable.
2. Structure: the floor, the roof and any steelwork need a property-specific design. Trussed roofs in particular cannot simply be cut.
3. Stairs and fire safety: a permanent stair and the escape strategy affect the attic and the floor below it, sometimes the whole house.
4. Intended use: a bedroom, an office, an ensuite and storage each create different requirements.
5. Services and finish: heating, electrics, plumbing, ventilation, joinery and decorating change the trade package considerably.
6. Access and logistics: scaffolding, parking, getting materials in and waste out all affect delivery — and vary a lot between a terrace in a city and a detached house in the country.
7. Professional fees: structural design, certification and any planning work may or may not be inside the number you are quoted.

How to compare written quotes

Ask every contractor to price the same written brief, then check each quote for the room and roof scope, structural and professional roles, stairs, insulation, ventilation, electrics, plumbing, windows, finishes, VAT, exclusions, programme, payment stages, waste removal and handover documents.

Agree how variations will be approved and priced before work begins. Most disputes about attic conversions are disputes about what was included.