Retention permission in Ireland: how to legalise unauthorised development

What is retention permission?

Retention permission is an application to keep development that has already happened without the planning permission it needed. Section 32 of the Planning and Development Act 2000 says permission is required for any development that is not exempted development. It also says that for unauthorised development, permission is required for its retention.

Examples can include an extension built larger than the permission allowed, a garage converted without permission, or a change of use that was never approved. The test is the same as for any other application: the council looks at the proper planning and sustainable development of the area.

When is retention permission needed?

You may need it if:

• You carried out development that needed permission and you did not get it.
• You built something that departs from the permission you were given.
• You bought a property that already has unauthorised development on it.
• Work you believed was exempted development did not meet every condition. See Do I need planning permission?.

If you are not sure whether work needed permission, you can ask the council for a declaration under Section 5. The exemptions guide explains how.

How does a retention application work?

The steps are close to those of a normal application. See How to apply for planning permission for the full list.

1. Gather evidence. Collect drawings of the work as it stands now, photographs and any earlier permissions.
2. Publish the notices. The newspaper notice and site notice must say the application is for retention. Fingal County Council’s checklist asks for the nature of the use of the structure to be retained and, in the site notice, the present tense.
3. Lodge the application. Use the retention fee, not the normal fee.
4. Wait for the decision. The decision period of 8 weeks from receipt of a valid application is the same as for other applications. See How long does planning permission take?

You cannot apply for outline permission for retention. The Regulations rule it out.

How much does retention cost?

The fee for retention is higher than for a normal application. Schedule 9 of the Regulations sets these figures:

Other classes of development have their own fees, which for many classes are three times the normal fee. The Schedule also sets overall maximums. Use the planning fee calculator for an estimate and confirm the figure with your council.

If the council refuses retention and you appeal, the appeal fee is also higher. An Coimisiún Pleanála lists a first-party appeal that includes retention, with no commercial development and no environmental report, at €660. A comparable appeal without retention is €220.

Which sections of the Act matter?

• Section 32 sets the general rule that permission is required, including for retention.
• Section 34 is the section under which the council decides applications. Section 34(12) says the council must refuse to consider an application to retain unauthorised development where an environmental impact assessment or an appropriate assessment was or is required.
• Section 40 limits the life of most permissions to 5 years, but the limit does not apply to a permission for the retention of a structure.

What is substitute consent?

Where development needed an environmental impact assessment or an appropriate assessment and it was not done, ordinary retention is not available. A separate route called substitute consent exists, and it is dealt with by An Coimisiún Pleanála. An application must include a remedial environmental report. It is a specialist process, so get professional advice and look at An Coimisiún Pleanála’s guidance.

What can happen if the development stays unauthorised?

The council has enforcement powers. It can issue a warning letter or an enforcement notice, and it can prosecute. Under Section 160, the High Court or Circuit Court can also order unauthorised development to stop or be removed, and the application can be made by the council or by any other person, whether or not they have an interest in the land.

Section 157 sets time limits. In general, for development where no permission has been granted, no warning letter or enforcement notice can issue, and no prosecution can start, more than 7 years after the development began. There are exceptions. This is a legal question, so do not assume the time limit applies to your situation.

Rules are changing, so check before you act

The Planning and Development Act 2024 will replace the 2000 Act, but it is being commenced in stages. The Irish Statute Book, updated to 21 October 2026, lists the repeal of sections 32 to 93 and sections 150 to 177Q of the 2000 Act, which cover permission, enforcement and substitute consent, as not yet commenced. The rules in this guide are therefore the 2000 Act as amended. Check the planning pages on gov.ie and your council’s website for any change.

Check before you apply

Whether retention is possible depends on the exact site and the history of the building. Zoning, protected structures, conservation areas and nearby nature sites can all change the answer. A pre-planning report checks zoning, protected structures and nature sites at an address, and you can read more on the pre-planning report page. Then confirm with your council, and take legal advice if you are unsure of your position.