Choose the works proposed to see, in plain English, the exempted development criteria that apply to them: the size, height and siting conditions in Schedule 2 to the Planning and Development Regulations 2001. The only formal answer, especially in a borderline case, is a declaration from the planning authority under section 5 of the 2000 Act (section 10 of the 2024 Act once Part 4 commences).
The size and height limits below are only half the test. An exemption in Schedule 2 can be lost, however small the works, where any of the following applies. These are the cases that most often catch householders out.
Where any of these may apply, or the works are close to a limit, the formal answer is a declaration from the planning authority under section 5 of the 2000 Act (section 10 of the 2024 Act once Part 4 commences). The 2001 Regulations, including these restrictions, continue in force after Part 4 commences under section 627 of the 2024 Act.
Please note. General information only, not legal or planning advice. Much of this is new legislation that has not yet been tested and could be subject to challenge, amendment or further regulation. For a definitive answer on a particular property or application, engage with the relevant planning authority.
The limits the checker works to, set out in one place, as we read Schedule 2 to the Planning and Development Regulations 2001 as amended, including S.I. 338 to 344 of 2026. Several of these classes are new and have not yet been interpreted by the courts or the Commission. Every class is subject to article 9 and, for a protected structure, section 57 of the 2000 Act (see Before Relying on Any Exemption), and a condition on an earlier permission can remove an exemption. Whether particular works are exempt depends on the facts; only the planning authority can give a definitive answer, by a declaration under section 5 of the 2000 Act, or section 10 of the 2024 Act once Part 4 commences.
A rear extension or conservatory to a house, or converting an attached garage or shed to the rear or side. Class 1 of Part 1 of Schedule 2, as substituted by S.I. 338 of 2026, in force 27 July 2026.
| Total floor area | 45 m² in total, counting every extension built since 1 October 1964, including one that had planning permission. Conditions 1(a) and 2(a). |
|---|---|
| Above ground floor | 12 m² for a terraced or semi-detached house; 20 m² for a detached house; again counting earlier extensions. Conditions 1(b), 1(c), 2(b) and 2(c). |
| Upstairs to the boundary | Any part above ground floor at least 2 m from any party boundary. Condition 3. |
| Open space | At least 25 m² of private open space left within the curtilage of the house. Since 27 July 2026 this is measured across the whole curtilage; before then, the rear only. Condition 5. |
| Wall height | No higher than the rear wall of the house; where the rear wall has a gable, no higher than the side walls. Condition 4(a) and (b). |
| Flat roof | Highest point, including any parapet, no higher than the eaves or parapet of the house. Condition 4(c). |
| Pitched or other roof | Highest point no higher than the highest part of the roof of the house. Condition 4(c). |
| Windows | Ground floor: at least 1 m from the boundary faced. Above ground floor: at least 8 m from the boundary faced (11 m before 27 July 2026). Condition 6. |
| Roof use | Not used as a balcony or terrace. Condition 7. |
| Which house | The main house only, not a detached house built under Class 3A. Condition 8. |
| Measuring | Class 1 does not define floor area. It is normally taken as the internal floor area, measured inside the external walls and including internal walls, as "gross floor space" is defined in article 5 of the 2001 Regulations. |
A detached garage, shed, greenhouse, store or similar structure. Class 3 of Part 1 of Schedule 2, as amended by S.I. 338 of 2026.
| Floor area | 30 m² in total, taken together with every other such structure already in the curtilage. Raised from 25 m² on 27 July 2026. Condition 2. |
|---|---|
| Height | 4 m with a tiled or slated pitched roof; 3 m with any other roof. Condition 5. |
| Position | Not forward of the front wall of the house. Condition 1. |
| Open space | At least 25 m² of private open space must remain to the rear or side. Condition 3. |
| Finish | A garage or structure to the side of the house must match the external finish of the house, and its roof covering if tiled or slated. Condition 4. |
Converting a garage, store or shed attached to the rear or side of the house into part of the house. Class 1, as substituted by S.I. 338 of 2026.
| Floor area | The conversion is an extension under Class 1, so its floor area counts towards the same 45 m² as any extension built since 1 October 1964, including permitted ones. The Extension calculator applies. Conditions 1 and 2. |
|---|---|
| Use | The converted space must be used as part of the house. A business use, such as a workshop open to customers, can be a material change of use that needs permission. |
A porch outside any external door of the house. Class 7.
| Floor area | Not more than 2 m². Condition 2. |
|---|---|
| Distance to road | At least 2 m from any road. Condition 1. |
| Height | 4 m with a tiled or slated pitched roof; 3 m with any other roof. Condition 3. |
The answer depends on what changes on the outside of the roof.
| Inside only | Works that affect only the interior of the house, or do not materially affect its external appearance so as to make it inconsistent with its own character or that of its neighbours, are exempted development under section 4(1)(h) of the 2000 Act. |
|---|---|
| Dormer | A dormer to the side or rear: internal volume not more than 30 m³, alone or with other dormers; no higher than the roof ridge; at least 20 cm set back from the eaves. Class 1B, S.I. 344 of 2026. |
| Front rooflights | Not more than two rooflights on the front roof plane, each not more than 100 cm long and 90 cm wide. Class 1C, S.I. 344 of 2026. |
| Habitable room | Using the attic as a bedroom brings in the Building Regulations (stairs, fire safety, ceiling heights) whether or not planning permission is needed. |
Attic conversions are the most common grey area. Whether internal works or a dormer meet the conditions is a question of fact on each house; a declaration from the planning authority settles it.
A gate, gateway, railing, wooden fence or wall within or bounding the curtilage of a house. Class 5.
| In front of the house | Not more than 1.2 m high, for a wall, fence, railing or gate in or bounding the garden in front of the house. Condition 1. |
|---|---|
| Elsewhere | Not more than 2 m high. Condition 1. |
| Walls | Every wall other than a dry or natural stone wall must be capped, and a concrete or concrete block wall visible from a road, path or public area must be rendered or plastered. Condition 2. |
| Not exempt | A metal palisade or other security fence. Condition 3. |
| Road access | The exemption is lost where the works form or materially widen a means of access to a public road whose surfaced carriageway is more than 4 m wide, or would endanger public safety by traffic hazard. Article 9(1)(a)(ii) and (iii). |
Paths, drains, ponds, landscaping and hard surfaces within the curtilage of a house. Class 6.
| Ground level | A path, drain, pond or landscaping must not raise or lower the ground by more than 1 m against the adjoining ground. Class 6(a). |
|---|---|
| Hard surface to the rear | A hard surface to the rear of the house, for a purpose incidental to the enjoyment of the house. Class 6(b)(i). |
| Front or side | A hard surface in the front garden, or the side garden, of 25 m² or more, or covering more than half of that garden, must be permeable or otherwise let rainwater soak into the ground. Class 6(b)(ii). |
| Road access | Making or widening an entrance onto a public road is a separate question: see Walls, Fences, Gates and Railings. |
Solar photovoltaic or thermal panels on a house or in its curtilage. Class 2(c), as substituted by S.I. 493 of 2022.
| On the roof | No limit on the share of the roof covered, but the panels may project no more than 15 cm from a pitched roof (50 cm from a flat roof) and must be at least 50 cm from the edge of the roof. Conditions 1 and 2. |
|---|---|
| On a wall | Panels on a wall are not exempted development. Condition 7. |
| Free-standing | Not forward of the front wall; a total aperture area of not more than 25 m²; not more than 2.5 m high; at least 25 m² of private open space left to the rear or side. Conditions 3 to 6. |
| Other limits | Panels causing hazardous glint or glare are not exempt. A free-standing array in an architectural conservation area is exempt only if it does not materially affect its character. Separate limits apply in a solar safeguarding zone near an airport, and works to a protected structure that affect its character need permission. |
Retrofit and household storage, all changed on 27 July 2026.
| External wall insulation | Not more than 150 mm thick on the front, rear or gable walls; not encroaching on a public road; and not materially affecting the external appearance so as to make it inconsistent with the house or its neighbours. Class 63, S.I. 341 of 2026. |
|---|---|
| Heat pump | A ground or air source heat pump: not more than 2.5 m² in total; at least 50 cm from any edge of the wall or roof it is mounted on; not encroaching on a public road; within the noise limits; ground level not changed by more than 1 m. The former bar on the front wall or roof was removed. Class 2(d), S.I. 342 of 2026. |
| Bike and bin store | Not more than 3.5 m² and 1.4 m high. To the front, it must be set back 0.6 m from the front wall of the house and must not reduce the open part of the front garden by more than half. Class 62, S.I. 341 of 2026. |
| Protected structures | Works to a protected structure that would materially affect its character, or in an architectural conservation area, can need permission. |
A detached house in the rear garden of a principal house, commonly referred to as a "modular" or "garden" home. Class 3A, S.I. 340 of 2026.
| Floor area | At least 32 m² and, taken together with any structures already built under Class 3, not more than 45 m². Condition 7. |
|---|---|
| Height | 4 m with a tiled or slated pitched roof; 3 m with any other roof. Condition 6. |
| Notify first | A notification must be made to the planning authority at least 14 days before work starts, confirming the site meets the requirements and giving the Eircode. Conditions 16 and 17. |
| Time limit | The works must be started and completed by 31 December 2030. Conditions 1 and 2. |
| Occupation | Occupied only with the main house; not sold or subdivided separately; not let as a short-term let; and the main house must be the owner's sole or main residence when work starts. Conditions 3, 19 and 20. |
| Services and siting | No separate utility connections; at least 0.6 m from any wall or party boundary; windows at least 0.6 m from the boundary they face; at least 25 m² of private open space left; no new access onto a road. Conditions 9 to 15. |
| Building Regulations | The Building Regulations, including fire safety, and the Building Control Regulations apply. Condition 4. |
Also new: a house may be subdivided to create one additional self-contained unit within the existing building, each unit at least 32 m², with the same 14-day notification (Class 1A, S.I. 339 of 2026). The garden home guide covers both.
Please note. General information only, not legal or planning advice. Much of this is new legislation that has not yet been tested and could be subject to challenge, amendment or further regulation. For a definitive answer on a particular property or application, engage with the relevant planning authority.
Class 1 of the 2001 Regulations, as amended by S.I. 338 of 2026, allows up to 45 m² in total, counting every extension built since 1 October 1964, with lower limits above ground floor (12 m² terraced or semi-detached, 20 m² detached) and other conditions on open space, boundaries, height and windows. Conditions on an earlier permission, or the restrictions in article 9, can remove the exemption.
Class 3A (S.I. 340 of 2026) can exempt a detached house of 32 m² to 45 m² in the rear garden if every condition is met, including notifying the planning authority at least 14 days before starting and completing by 31 December 2030. These are new provisions with many conditions. See the garden home guide.
Class 3, as amended by S.I. 338 of 2026, allows up to 30 m² in total with other such structures, behind the front wall, generally up to 4 m high with a pitched tiled or slated roof or 3 m otherwise, leaving at least 25 m² of open space.
Class 1B (S.I. 344 of 2026) can exempt a side or rear dormer of up to 30 m³, below the ridge and set back at least 20 cm from the eaves. A front dormer is not covered. Up to two front rooflights within set sizes may be exempt under Class 1C.
Class 5 allows 1.2 m in front of the house and 2 m elsewhere, with conditions on capping and rendering. A metal palisade fence is not covered, and works that create or widen an access onto a public road more than 4 m wide lose the exemption under article 9.
Roof panels can be exempt under Class 2(c) if they project no more than 15 cm from a pitched roof (50 cm from a flat roof) and stay 50 cm from its edge. Wall-mounted panels are not covered. Different rules apply to protected structures, conservation areas and areas near airports.
Only the planning authority can give a definitive answer, by a declaration under section 5 of the 2000 Act (section 10 of the 2024 Act once Part 4 commences). Whether works meet the conditions depends on the facts of each property.
These guides and tools are published as a public service and are kept to the primary legislation. They are not a free advice line, and individual queries are not answered by email or phone. For a general question about a particular property, the planning authority's planning department and Citizens Information are the starting points, and a declaration under section 5 is the formal answer. Where a matter needs professional work, the practice takes instructions on a fee basis: from developers, landowners, investors and public bodies, and from private clients, for example on retention or regularisation of unauthorised development or a change of use, and occasionally a one-off house, subject to capacity.