Exempted Development in Ireland

What is Exempted Development?

Certain types of development are "exempted" from the requirement to obtain planning permission in Ireland. These exemptions are set out in Schedule 2 of the Planning and Development Regulations 2001 (as amended). Under the Planning and Development Act 2024, all exempted development is now defined exclusively through Regulations rather than in the Act itself.

This guide sets out the current thresholds, including the major changes made by SI 338-344 of 2026, in operation since 27 July 2026. Always check with your local authority, as conditions are strict and cumulative limits apply.

Extensions

Ground floor (rear) extensions:

• Total floor area added must not exceed 45 square metres (raised from 40 square metres on 27 July 2026 by SI 338/2026)
• Must not reduce private open space below 25 square metres
• Must be to the rear of the house and behind the rear building line

Above-ground extensions:

• Detached houses: up to 20 square metres
• Semi-detached and terraced houses: up to 12 square metres
• Any windows at above-ground level must be at least 8 metres from the boundary they face (reduced from 11 metres in July 2026)
• The roof of an extension cannot be used as a balcony or terrace

These are cumulative limits — all previous extensions since 1 October 1964, including ones granted planning permission, count towards the total.

Roof Windows and Dormers

• Velux/roof windows on the rear roof slope are generally exempt
• Velux on the front or side elevation require planning permission
• Roof lights must not cover more than 20% of the roof slope area
• Must not protrude more than 15cm from the roof surface
• Dormer windows always require planning permission on any elevation — they change the external appearance of the building

Garden Structures (Sheds, Garages, Garden Rooms)

• Up to 30 square metres floor area (raised from 25 square metres on 27 July 2026 by SI 338/2026)
• Maximum height 4 metres for a tiled or slated pitched roof (or 3 metres in any other case)
• Total coverage of all such structures, including existing ones, must not exceed 30 square metres
• Must not be forward of the front wall of the house
• Must leave at least 25 square metres of private open space to the rear or side of the house
• Must not be used for human habitation or commercial purposes — for a cabin you can live in, see Class 3A below

Garden Cabins and Modular Homes (Class 3A) — NEW

Since 27 July 2026 (SI 340/2026), a detached habitable dwelling of 32 to 45 square metres can be built, erected, or placed in the rear garden of a house without planning permission. This is the biggest change to household exemptions in decades. Headline conditions:

• Floor area between 32 and 45 square metres, counted together with any existing exempt garden structures
• Rear garden only, at least 0.6 metres from every boundary, leaving 25 square metres of private open space
• Must share the main house's services — no separate utility connections
• Mobile homes and caravans are explicitly excluded — the structure cannot be temporary in nature
• You must notify the planning authority in writing at least 14 days before starting, including the Eircode
• Full Building Regulations compliance is still required, and works must be commenced and completed by 31 December 2030

See our dedicated Log Cabins, Mobile Homes & Garden Cabins guide for the complete conditions, the notification procedure, and what to do if your project doesn't qualify. You can also run your project through the free exemption checker.

Walls and Fences

• Front boundary walls/fences up to 1.2 metres
• Side and rear walls up to 2 metres

Solar Panels

Since October 2022 (SI 493/2022), the solar exemptions are far more generous:

• Houses: no area limit anywhere in Ireland — Solar Safeguarding Zones do not restrict houses
• Apartment, commercial, industrial, and agricultural buildings: no area limit outside Solar Safeguarding Zones
• Within one of the 43 Solar Safeguarding Zones (around airports and aerodromes), buildings other than houses are limited to 300 square metres per roof, and you must notify the local authority in writing within 4 weeks of starting work
• Panels must not be higher than the plane of the roof

You can check whether your building sits inside a Solar Safeguarding Zone with our free exemption checker. For panel costs, SEAI grants, and choosing an installer, see SolarInfo.ie.

Other Common Exemptions

• Internal alterations that don't affect the external appearance or structure
• Painting the exterior (unless in an Architectural Conservation Area)
• Satellite dishes — one per house, max 1 metre diameter, not on the front elevation
• Hard surfaces (driveways, patios) — consider drainage requirements
• Central heating systems and boiler houses within certain limits
• Heat pumps within certain size and noise limits

Protected Structures and Conservation Areas

Exemptions do not apply to protected structures (buildings on the Record of Protected Structures). If your property is a protected structure, virtually all external and many internal works require planning permission.

For protected structures, you can apply for a Section 57 Declaration from your local authority. This is a free service (unlike the €80 Section 5 Declaration) that tells you what types of work would or would not materially affect the character of your building. Every local authority has an Architectural Conservation Officer who can advise.

Architectural Conservation Areas (ACAs) also restrict exemptions. In an ACA, external alterations that would affect the character of the area require planning permission, even if they would normally be exempt. This includes replacing windows or doors, cleaning brickwork, re-slating roofs, and painting the exterior.

When Exemptions Do Not Apply

Even if your project falls within the thresholds above, it is not exempt if:

• Your property is a protected structure or in an ACA
• The development would contravene a condition of a previous planning permission
• The cumulative total of exempted works exceeds the limits (all previous exempted extensions count)
• The development would create a traffic hazard or obstruct road users' sight lines
• The development would be inconsistent with any use specified in a planning permission

Recent Changes

• October 2022: Solar panel exemptions expanded significantly for residential rooftops
• 2024: Commercial-to-residential conversion exemption extended to 31 December 2028 (applies to vacant commercial premises)
• 2024: Agricultural exemptions updated — first-ever exemption for stand-alone slurry storage; animal housing limits increased from 200 to 300 square metres
• 27 July 2026: SI 338-344 of 2026 came into operation — the largest package of new household exemptions in decades. Rear extensions raised from 40 to 45 square metres; garden structures raised from 25 to 30 square metres; new Class 3A exemption for habitable garden dwellings of 32-45 square metres (time-limited to 31 December 2030); new Class 1A exemption for subdividing a house into two self-contained units of at least 32 square metres each; plus new exemptions for bicycle/bin stores, external wall insulation, heat pumps, chimney removal, dormer windows, and front rooflights

How to Verify

1. Check the current regulations at citizensinformation.ie
2. Contact your local authority's planning department
3. Apply for a Section 5 Declaration (€80, decision within 4 weeks) for legal certainty — see our Do I Need Planning Permission guide
4. For protected structures, apply for a Section 57 Declaration (free)

Disclaimer

This guide provides general information about exempted development in Ireland based on the Planning and Development Regulations 2001 (as amended). Exemption rules are complex, have many conditions, and are subject to change. Always verify with your local authority or a qualified planning professional before starting work.