Last updated: August 2026. Human compiled and fact checked against each named source on 20 August 2026.
Attic conversions sit inside the fastest growing category of home planning permissions in Ireland. Permissions for alterations and conversions to dwellings rose 38.1% in 2025, dormer roof boxes and roof lights became exempt from planning permission on 27 July 2026, and applications for SEAI attic insulation grants were up 81% in the first quarter of 2026. This page gathers the current Irish figures on attic and loft conversions, the planning categories they fall into, the homes most suited to them and the grants that support the work, each linked to its primary source. It is a companion to our home renovation and extension statistics for Ireland.
Key Attic Conversion Statistics for Ireland at a Glance
- 4,138 planning permissions were granted for alterations and conversions to dwellings in 2025, the CSO category that attic and loft conversions fall into, up 38.1% on the 2,996 granted in 2024 (both totals and the change calculated from quarterly data). Source: CSO, table BHQ13
- 1,782 of those permissions, 43.1% (calculated), were in the four Dublin local authorities. Source: CSO, table BHQ13
- Across all building types, 5,469 alterations and conversions permissions were granted in 2025, and 1,595 in Quarter 1 2026 alone, up 45.0% year on year. Source: CSO, Planning Permissions Quarter 4 and Year 2025 and Quarter 1 2026
- Dormer roof boxes and roof lights on a principal dwelling became exempt from planning permission on 27 July 2026. Source: Department of Housing, Local Government and Heritage, 27 July 2026
- SEAI received over 1,730 applications for attic insulation grants in Quarter 1 2026, up 81% year on year. Source: SEAI, 21 April 2026
- The SEAI attic insulation grant is worth up to €2,000, or €2,500 for first time buyers and homeowners on qualifying welfare payments. Source: SEAI individual energy grants
- More than 655,000 occupied Irish dwellings, 36% of the occupied stock, have three bedrooms, the classic candidate for an attic bedroom. Source: CSO, Census 2022 Profile 2
- Semi detached and terraced houses make up 839,110 of Ireland’s occupied homes, 45.7% nationally and 63.3% in Dublin (calculated). Source: CSO, Census 2022, table FY033A
- 58,869 occupied dwellings averaged more than one person per room in Census 2022, while Eurostat records 67% of the Irish population living in under-occupied homes. Sources: CSO, Census 2022 Profile 2 and Eurostat, Housing in Europe 2025
- Nearly 72,000 occupied dwellings, 4% of the occupied stock, had no working smoke alarm in Census 2022, a reminder that a converted attic must meet Fire Regulations. Source: CSO, Census 2022 Profile 2
How Attic Conversions Appear in the Planning Figures
The CSO does not count attic conversions as a separate line. They sit inside the alterations and conversions category of the quarterly Planning Permissions release, alongside garage conversions and internal remodelling, so the figures on this page describe that category and are labelled as such. In 2025 there were 5,469 alterations and conversions permissions granted across all building types, out of 29,574 permissions for all developments, according to the CSO Planning Permissions release for Quarter 4 and Year 2025.
Summing the four quarters of CSO table BHQ13 for dwellings only gives 4,138 permissions for alterations and conversions to homes in 2025, up from 2,996 in 2024, an increase of 38.1% (calculated). That is the strongest year in the series since the pandemic peak of 4,117 in 2021, and well above the 3,082 recorded in 2019. The growth has continued into 2026: the Quarter 1 2026 release records 1,595 alterations and conversions permissions across all building types, up 45.0% year on year, of which 1,240 related to dwellings, up from 778 in Quarter 1 2025, a rise of 59.4% (calculated).
The table below shows the category’s recent path, with all figures calculated as annual sums of the quarterly data in CSO table BHQ13.
| Year | Alterations and conversions permissions, dwellings, State | Of which Dublin | Dublin share (calculated) |
|---|---|---|---|
| 2019 | 3,082 | 1,397 | 45.3% |
| 2020 | 2,950 | 1,213 | 41.1% |
| 2021 | 4,117 | 1,871 | 45.4% |
| 2022 | 3,037 | 1,403 | 46.2% |
| 2023 | 2,874 | 1,359 | 47.3% |
| 2024 | 2,996 | 1,344 | 44.9% |
| 2025 | 4,138 | 1,782 | 43.1% |
Not every attic conversion needs planning permission, so these figures understate the true volume of work. A conversion that stays inside the existing roof, or that uses the roof light and dormer exemptions introduced in July 2026, may never appear in the planning statistics at all.
Dublin Takes an Outsized Share
Dublin dominates this category even more than it dominates extensions. The four Dublin local authorities accounted for 1,782 of the 4,138 dwelling alterations and conversions permissions in 2025, 43.1% (calculated from CSO table BHQ13), against Dublin’s 28.2% share of the State’s occupied households (calculated from Census 2022 table FY033A). The Mid-East region (Kildare, Meath, Wicklow and Louth) added a further 512 permissions. In Quarter 1 2026 Dublin recorded 509 of the State’s 1,240 dwelling alterations permissions, 41.0% (calculated).
The reason is the shape of the stock. Semi detached and terraced houses, the house types attic conversions suit best, make up 63.3% of Dublin’s 518,490 occupied homes against 45.7% nationally (calculated from the same Census table). On a tight Dublin plot, the roof is often the only direction left to grow.
The July 2026 Dormer and Roof Light Exemption
The Exempted Development Regulations that took effect on 27 July 2026 introduced, for the first time, an exemption for extending a dwelling by adding a dormer roof box and/or roof light, as announced by the Department of Housing, Local Government and Heritage. The same regulations raised the general extension exemption from 40 to 45 square metres and made external wall insulation exempt. The announcement is explicit that all relevant Building Regulations, Building Control and Fire Regulations, including those for habitable dwellings, continue to apply, so an attic conversion still needs to meet the standards for a habitable room even where no planning application is required. The detailed conditions in the regulations decide whether a specific dormer qualifies, and protected structures carry additional requirements.
Why Irish Homes Convert Their Attics
The pressure for space is national. Census 2022 recorded population growth of 8% since 2016 against housing stock growth of 5%, and 58,869 occupied dwellings with an average of more than one person per room, according to the CSO Census 2022 Profile 2. More than 655,000 occupied dwellings, 36% of the stock, have exactly three bedrooms, and a three bed semi with a growing family is the classic attic conversion candidate.
At the same time, Ireland’s houses have room to give. Eurostat’s Housing in Europe, 2025 edition reports that 90% of the Irish population lived in a house in 2024, the highest share in the EU, and that 67% lived in an under-occupied home, the second highest share after Cyprus. An unconverted attic is the clearest example of that unused capacity: converting it adds a room without adding to the footprint, which is why permissions for alterations and conversions are growing faster than permissions for extensions (38.1% against 6.0% for dwelling extensions in 2025, both calculated from CSO table BHQ13).
Moving instead is expensive and supply is tight. The CSO recorded 36,284 new dwelling completions in 2025, the highest since its series began in 2011, but that record year still added only about 1.7% to a stock of more than 2.1 million dwellings (calculated), per the New Dwelling Completions release for Quarter 4 2025. For many households, going up is the practical alternative to moving out.
The Age of the Roofs Being Converted
Most of the candidate housing is old. Using Census 2022 table FY033A and excluding households where the year of construction was not stated, 523,039 occupied Irish homes (29.2%) were built before 1971 and 1,200,514 (66.9%) before 2001; in the four Dublin local authorities the pre-2001 share rises to 72.5% (all calculated). The construction era matters for feasibility, because houses built before prefabricated roof trusses became standard generally have roof structures that are simpler to open up, while trussed roofs from later decades need engineered structural work. Either way the age profile means the typical conversion also involves insulating a roof built to older standards, which is where the energy grants below come in.
Attic Insulation and Energy Performance
The measuring stick changed on 24 May 2026, when the BER scale was cut to 8 categories and a new A0 rating was created for zero emission homes; 64% of rated Irish homes still sit at C or lower. Our home energy and retrofit statistics for Ireland tracks the new scale and the grant programmes in full.
The attic is also where home energy work concentrates. SEAI describes attic and rafter insulation as often the most cost effective upgrade a home can make, and its individual grants page lists the attic insulation grant at up to €2,000, rising to €2,500 for first time buyers and homeowners on qualifying welfare payments. Demand is climbing steeply: SEAI received over 1,730 applications for attic insulation grants in the first quarter of 2026, up 81% on a year earlier, within a quarter that saw 29,000 grant applications overall, according to the SEAI statement of 21 April 2026. Over 58,000 SEAI supported home energy upgrades were completed in 2025, the highest year on record, per the SEAI end of year statement.
Energy ratings show why the work matters in older roofs. Of the 1.35 million unique dwellings rated since 2009, 35% carry an A or B rating and 65% are rated C or lower (remainder calculated), and A ratings went to over 99% of dwellings built since 2020 but only 6% of those built between 2005 and 2009, according to the CSO Domestic Building Energy Ratings release for Quarter 1 2026. Among homes assessed more than once, over 220,000 improved by at least one full letter grade, and insulating the roof during a conversion is one of the standard routes to that improvement.
Safety, Fire Regulations and the Converted Attic
A converted attic is a habitable room and must meet Building Regulations for structure, fire safety, ventilation, insulation and stairs regardless of whether planning permission was needed, a point the Department of Housing restated in its July 2026 exemptions announcement. The baseline is not reassuring: Census 2022 found nearly 72,000 occupied dwellings, 4% of the occupied stock, had no working smoke alarm, with detached houses the most likely to lack one, per the CSO Census 2022 Profile 2. A compliant conversion adds interlinked mains powered smoke alarms and a protected stairs, which for many houses is a safety upgrade over the starting position.
Attic Conversions Against Extensions
The two routes to more space are growing together, but conversions are growing faster. In 2025 there were 7,193 dwelling extension permissions against 4,138 dwelling alterations and conversions permissions; in 2024 the figures were 6,784 and 2,996 (all calculated from CSO table BHQ13). The full extension picture, including floor areas, regional shares, grants and costs, is on our home renovation and extension statistics page, which this page will be read alongside.
Method and Sources
Every figure was taken from the named primary source on 20 August 2026: CSO Planning Permissions Quarter 1 2026 (published 10 June 2026) and Quarter 4 and Year 2025 (12 March 2026) with PxStat table BHQ13; CSO Census 2022 Profile 2 Housing in Ireland and table FY033A; CSO Domestic Building Energy Ratings Quarter 1 2026 (1 May 2026); CSO New Dwelling Completions Quarter 4 2025 (29 January 2026); SEAI statements of 9 January and 21 April 2026 and the SEAI individual grants page; the Department of Housing exemptions announcement of 27 July 2026; and Eurostat Housing in Europe 2025. The CSO groups attic conversions inside its alterations and conversions category, so those figures describe the whole category, not attic conversions alone, and this is stated wherever the figures appear. Figures marked calculated were derived by OS Holding from the cited table (annual sums of quarterly data, regional shares, and year on year changes). The page will be refreshed when CSO Planning Permissions Quarter 2 2026 publishes (expected September 2026) and after each SEAI statement and exemptions change.
How OS Holding Helps
OS Holding designs and builds attic conversions across Dublin, from roof light conversions to dormers, alongside house extensions and insulation work. If you want to know whether your roof suits a conversion under the new dormer exemption, contact the team for a site visit and a written quote. Journalists and researchers are welcome to quote any figure here with a link to the source and to this page.
