Attic Conversion Cost in Ireland (2026 Guide)
An attic conversion is one of the most cost-effective ways to add living space to your home in Ireland. Converting an unused attic into a bedroom, home office, or playroom can add significant value to your property without the expense and disruption of a full extension — but understanding the true cost before you start is essential.
In 2026, attic conversion costs in Ireland range from approximately €15,000 to €45,000 depending on the size of the attic, the type of conversion, the specification of finishes, and the complexity of the structural work involved. The wide range reflects the significant variation between a basic room-in-roof conversion and a fully dormer-extended attic with en-suite bathroom and bespoke joinery.
Labour costs remain the dominant cost driver for attic conversions in Ireland in 2026. The persistent shortage of skilled tradespeople — particularly carpenters, electricians, and plasterers — continues to push rates upward, particularly in Dublin and Cork. Material costs for insulation, structural steel, and plasterboard have also remained elevated compared to pre-2022 levels, though price growth has slowed considerably through 2025 and into 2026.
Key figure for 2026: The average cost of a standard attic conversion in Ireland — converting an existing roof space into a habitable room without dormer extension — ranges from €15,000 to €25,000. A full dormer attic conversion with bathroom typically costs between €30,000 and €45,000.
This guide covers all the main attic conversion types available in Ireland, breaks down costs by conversion type and size, explains what is and is not included in contractor quotes, and answers the most common questions Irish homeowners have about attic conversion costs, planning permission, and the return on investment a conversion delivers.
Types of Attic Conversion in Ireland and Their Costs
Not all attic conversions are the same. The type of conversion you choose will be the single biggest determinant of cost, timescale, and the amount of usable space you gain. There are four main attic conversion types carried out in Ireland, each suited to different roof structures, budgets, and planning situations.
Attic Conversion Cost Breakdown by Size (Ireland 2026)
The floor area of the converted space has a direct impact on total cost. Below are indicative cost ranges for the most common attic sizes in Irish homes, broken down by conversion type.
| Conversion Type | Floor Area | Basic Finish | Standard Finish | High Spec Finish |
|---|---|---|---|---|
| Room in Roof | 20 – 30 m² | €15,000 | €19,000 | €25,000 |
| Dormer (single) | 25 – 35 m² | €25,000 | €32,000 | €40,000 |
| Dormer (with en-suite) | 30 – 40 m² | €30,000 | €37,000 | €45,000 |
| Hip to Gable | 25 – 40 m² | €20,000 | €27,000 | €35,000 |
| Mansard | 35 – 50 m² | €35,000 | €44,000 | €55,000 |
| Figures are indicative estimates for Ireland in 2026 including VAT at 13.5%. Actual costs vary by location, specification, and contractor. Always obtain at least three quotes. | ||||
Dublin and Cork premium: Expect attic conversion costs in Dublin City and suburbs to run 15 to 25 per cent above the figures shown above. Cork City rates are typically 10 to 15 per cent above the national average. Rural counties generally align with or fall slightly below the figures in this table.
What Affects the Cost of an Attic Conversion in Ireland?
Beyond the conversion type and floor area, a number of specific factors can push your attic conversion cost significantly above or below the average figures quoted in this guide. Understanding these variables before you approach contractors will help you build a more accurate budget and avoid unexpected costs mid-project.
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Existing roof structure Older Irish homes built before the 1970s typically have cut rafter roofs with plenty of usable headroom, making conversion straightforward. Homes built from the 1980s onward often have trussed rafter roofs, which require structural alterations to create usable space — adding €3,000 to €8,000 to the project cost.
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Head height Building Regulations in Ireland require a minimum head height of 2.2 metres over at least 50 per cent of the usable floor area for a room to be classified as habitable. If your existing roof space does not meet this requirement, a dormer extension will be necessary to achieve compliance, significantly increasing cost.
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Velux windows vs dormer windows Velux roof windows are the most cost-effective way to bring light and ventilation into an attic conversion. A standard Velux installation costs €800 to €1,500 per window including fitting. Dormer windows, which project outward from the roofline, cost considerably more — typically €4,000 to €8,000 each — but provide significantly more headroom and natural light.
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En-suite bathroom Adding an en-suite bathroom to an attic conversion adds €8,000 to €15,000 to the total project cost in Ireland in 2026, depending on the specification of sanitaryware and tiling. The proximity of existing soil pipes and the need to route new plumbing through the floors below are the primary cost drivers.
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Insulation specification Attic conversions in Ireland must comply with Part L of the Building Regulations, requiring high-performance thermal insulation between and below the rafters. Spray foam insulation, rigid PIR boards, and mineral wool all have different costs and performance characteristics. Expect to spend €2,500 to €6,000 on insulation alone depending on the area and specification.
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Staircase design A new staircase to the converted attic is a mandatory requirement under Building Regulations — a fixed stair, not a loft ladder. Staircase costs in Ireland range from €1,800 for a basic straight flight to €6,000 or more for a space-saving alternating tread or bespoke joinery design. The available footprint on the floor below also dictates the type of stair that can be fitted.
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Electrical and fire safety All attic conversions require a dedicated electrical circuit, lighting, sockets, and mains-wired smoke and heat detectors connected to the existing alarm system. Electrical work typically adds €1,500 to €3,500 to the project. A fire-rated door at the base of the attic staircase is also a Building Regulation requirement.
Planning Permission for Attic Conversions in Ireland
Whether your attic conversion requires planning permission in Ireland depends primarily on whether the works involve any external alterations to the roofline. Internal conversions that do not change the external appearance of the roof are generally exempt from planning permission under the Planning and Development Regulations. Any works that alter the roofline — including dormer windows, hip to gable extensions, or mansard conversions — will typically require full planning permission from your local authority.
- Room in roof with Velux windows only
- No change to external roofline
- Velux windows on rear elevation only
- Internal structural alterations only
- No increase in ridge height
- Dormer window or extension
- Hip to gable conversion
- Mansard roof conversion
- Any works on a protected structure
- Velux windows on front elevation
Important: Even where planning permission is not required, all attic conversions in Ireland must comply with Building Regulations and require a Commencement Notice submitted to your local authority before works begin. Failure to comply can affect your ability to sell the property in future.
Is an Attic Conversion Worth It in Ireland?
For most Irish homeowners, an attic conversion represents excellent value for money compared to other forms of home extension. The cost per square metre of usable space gained is typically lower than a ground floor extension, the disruption to daily life is minimal once structural works are complete, and the addition of a habitable room adds measurable value to the property at resale.
Property professionals in Ireland generally estimate that a well-executed attic conversion adds between 10 and 15 per cent to the market value of a property, depending on location and the quality of the finish. In Dublin and Cork where space is at a premium, the value uplift can be even higher — particularly where the conversion adds a fourth bedroom. If roofing works are required as part of your conversion, use our roof cost calculator to estimate costs before approaching contractors.
Frequently Asked Questions
How long does an attic conversion take in Ireland?
Do I need an architect for an attic conversion in Ireland?
Does an attic conversion add value to a house in Ireland?
What is the cheapest type of attic conversion in Ireland?
Will my attic conversion affect my roof?
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All figures updated for 2026 — Irish labour and material rates