Sunrooms and conservatories in Cork: planning, conservation areas and builders

Quick answer: a rear sunroom or conservatory in Cork is normally exempt from planning if it is single-storey, no more than 45 m² including earlier extensions (the limit rose from 40 m² on 27 July 2026) and leaves 25 m² of rear garden. If your house is a protected structure or sits in one of Cork City’s architectural conservation areas such as Shandon, the Mardyke or Douglas Road, talk to the council first. Where permission is needed, Cork City Council charges development contributions of €49.87 per m² (before indexation) only on extension area above the first 40 m².

A note on words: in Ireland a sunroom usually means a builder’s extension with big windows and a solid, insulated roof; a conservatory is mostly glass; an orangery has solid piers and a roof lantern. Planning law treats all three alike. Our Irish costs guide explains how the choice changes the price.

The national rule: 45 m² to the rear, since 27 July 2026

Most single-storey sunrooms at the back of a house are exempted development under Class 1 of Schedule 2 to the Planning and Development Regulations 2001 (S.I. 600 of 2001). For more than 20 years the limit was 40 m². The Planning and Development (Exempted Development (Act of 2000)) Regulations 2026 (S.I. 338 of 2026) raised it to 45 m² from 27 July 2026. The main conditions are:

Class 1 condition	Limit from 27 July 2026
Where it can go	To the rear of the house only (the exemption expressly includes a conservatory)
Floor area	Not more than 45 m², counting every earlier extension built after 1 October 1964, including ones that had planning permission
Above ground floor	Not more than 12 m² (terraced or semi-detached) or 20 m² (detached), and at least 2 m from any boundary
Height	Not higher than the house, with further rules on height, windows near boundaries and roof use
Garden left behind	At least 25 m² of private open space must remain at the back of the house

Sources: S.I. No. 338/2026 (irishstatutebook.ie); Planning permission for altering your house, updated 27 July 2026 (citizensinformation.ie); Circular PLR 02/2026 (gov.ie).

The exemption can be lost for a protected structure (works are exempt only if they would not materially affect its character), in an architectural conservation area (ACA), where exterior works are restricted, or where an earlier permission removed exempted development rights. For a written answer, ask the council for a Section 5 declaration (Section 57 for a protected structure). Our guide to planning permission in Ireland: existing extensions, boundaries and exemption checks walks through the questions.

Which council? Cork City or Cork County

Cork City Council covers the city, including the suburbs it took over in the boundary extension. Cork County Council covers the rest of the county, from Midleton to Bantry, with its own development plan, protected structures and contribution scheme. Check which council your address falls under before you read any local rule. This page covers Cork City Council.

Architectural conservation areas and protected structures in Cork City

The Cork City Development Plan 2022–2028 keeps a Record of Protected Structures and a list of architectural conservation areas. The existing ACAs named in the plan’s built heritage objectives include:

Shandon, Blackpool, North Main Street, Paul Street and Coburg Street/Saint Patrick’s Hill
The Mardyke and North Mall/The Marsh
Albert Road, Albert Quay and Victoria Road
Douglas Road-Northwest, Ballinlough Road (Annville/Ardeevin group), Bethesda Row on the Old Blackrock Road and Greenmount
Lower Glanmire Road, Grattan Hill and Castleview Terrace, plus several small terrace groups such as Railway Cottages on Anglesea Street

Many of these are terraces of 19th-century houses where the rear gardens are small. Inside an ACA the exemption regulations restrict exterior works, and the plan’s standards focus on keeping historic roofs, walls and windows. For a protected structure, the owner can ask the council for a Section 57 declaration on which works would not affect its character.

Cork City development contributions

Development contributions only apply if your sunroom needs planning permission. Cork City Council’s Development Contribution Scheme 2023–2029 sets these rules for home extensions:

Item	Cork City Council scheme
General contribution rate	€49.87 per m² of gross internal floor area, from 14 February 2023, subject to indexation
House extensions	First 40 m² exempt (only one exemption per property; later extensions above 40 m² are charged)
Works to protected structures to a high conservation standard	100% exempt, excluding ancillary new development that uses extra services
Extensions of up to 50% of the original size of a protected structure	50% reduction
Supplementary scheme (suburban rail)	Extra charge within 1 km of the Cork–Blarney, Cork–Cobh and Cork–Midleton lines
Example: 50 m² extension needing permission	10 m² x €49.87 = €498.70 before indexation and any rail supplement (our arithmetic)

Source: Development Contribution Scheme 2023–2029 and Adopted Development Contributions Scheme (corkcity.ie). The contribution scheme still says 40 m²; it had not been updated for the July 2026 planning change when we checked.

Building control, BCAR and fees

Exempt or not, every extension must meet the Building Regulations, including energy (Part L) and safe glazing. A commencement notice, filed on the Building Control Management System 14 to 28 days before work starts, is needed where the work needs planning permission; an exempt sunroom does not normally need one. From 27 July 2026 (S.I. 359 of 2026) the BCAR certification rules apply to extensions to a dwelling over 45 m² (40 m² before): compliance documents, a design certificate, an Assigned Certifier and a builder’s undertaking, unless the owner signs an opt-out declaration. The notice costs €30 per building. If you need planning permission, the national fee is €34 for a house extension, or €102 (or €2.50 per m², if greater) to retain one already built.

Sources: Building Control Regulations 1997, article 9 as revised (revisedacts.lawreform.ie); Commencement Notices FAQs (corkcoco.ie); Planning fees payable (clarecoco.ie). Some council pages still show the old 40 m² figure.

Typical private prices

We have not found a reliable sunroom price survey for Cork alone, so use the national ranges in our Irish costs guide: Property Blueprint Co. (August 2026) puts an insulated warm-roof sunroom at €18,000–€35,000 and a basic uPVC conservatory at €8,000–€15,000, and Norman Pratt Conservatories uses €1,000–€2,000 per m² as a rule of thumb for a builder’s sunroom. Bases, electrics, heating and flooring are often extra; see what to include in a realistic budget.

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How to choose a builder in Cork

Check the register. The Construction Industry Register Ireland (CIRI) is becoming a statutory register under the Regulation of Providers of Building Works Act 2022, phased in from 2026 starting with larger housing builders, so a small extension builder may not be on it yet. Ask, and check the register.
Electrics and gas. New circuits should be installed and certified by a Safe Electric registered electrical contractor, and any gas work done by a Registered Gas Installer.
Who signs off? Over 45 m², ask who will be Assigned Certifier, or whether you are being asked to opt out, and whether the price includes VAT, the base, electrics, heating and flooring.
Cooling-off. Under the Consumer Rights Act 2022 you generally have 14 days to cancel a contract signed away from the builder’s premises, for example at your kitchen table. The CCPC explains the exceptions.
Pay in stages. Tie payments to finished stages rather than paying most of the price up front. Our guide to surveys, contracts and payment stages has a checklist.
Flood and ground checks. Much of central Cork is built on reclaimed marsh beside the Lee, and the plan describes The Marsh as essentially a marsh. Ask how the base will be designed for your ground; our guide to foundations and ground conditions explains why.

Conservatory and sunroom firms serving Cork

These businesses appear in public business listings for the Cork area. We have not checked their work, prices, registrations or insurance, and they have not paid to appear.