Planning Permission in Ireland: A Homeowner's Complete Guide

By Pádraig Ryan | 20 February 2026 | 6 min read

Planning permission is one of the most misunderstood aspects of building work in Ireland. Many homeowners either assume they need it for everything or assume they do not need it at all — and both can lead to expensive problems. Whether you are planning an extension, a conversion, or new build work in Tipperary, this guide covers exactly what you need to know.

What Is Exempted Development?

Under the Planning and Development Act 2000 (as amended), certain types of work are classified as "exempted development" and do not require planning permission. For houses, this generally includes extensions to the rear of the property up to 40 square metres (subject to conditions), internal alterations that do not affect the external appearance, the construction of a garden shed or garage up to 25 square metres, and certain boundary walls and fences up to specified heights.

However, there are important conditions attached. The extension must not reduce the private open space at the rear of the house to less than 25 square metres. The roof height of the extension must not exceed the roof height of the original house. And if your house is in an architectural conservation area or is a protected structure, different rules apply entirely. Always check with your local authority in Tipperary before assuming work is exempt.

When Do You Need Planning Permission?

You will need full planning permission for any extension that exceeds the exempted development limits, any work to the front of the house that materially affects its external appearance, change of use (for example, converting a garage into a separate dwelling), two-storey extensions in most cases, and any work on a protected structure or within an architectural conservation area.

In Tipperary, you apply to the local authority planning department. The current application fee for a house extension is EUR 34 per square metre, with a minimum of EUR 80. A retention permission application (for work already done without permission) costs significantly more and is not guaranteed to be approved.

The Application Process

A planning application requires detailed drawings (typically prepared by an architect or architectural technician), a site layout plan, a site notice and newspaper notice, photographs of the existing site, and completed application forms. Your local authority has eight weeks to make a decision, though they may request further information which extends the timeline. Third parties (typically neighbours) have five weeks from the application date to submit observations or objections.

In our experience working across Clonmel, applications that include clear, professional drawings and address potential concerns upfront — such as overlooking, overshadowing, and drainage — are far more likely to be granted without complications.

Common Mistakes Homeowners Make

The most common mistake we see is homeowners proceeding with work that they believe is exempted but is not. The 40 square metre exemption, for instance, is a cumulative limit — it includes any previous extensions to the property, even those done by a previous owner. Many people do not realise this until an issue arises during a property sale.

Another frequent error is failing to comply with building regulations even when planning permission is not required. Exempted development still needs to comply with Part L (energy), Part B (fire), Part M (access), and all other parts of the Building Regulations. Since the introduction of BC(A)R in 2014, a Commencement Notice or opt-out must be filed before starting most building work.

How a Good Builder Can Help

An experienced builder can advise you early in the process on whether your project is likely to need planning permission and can recommend reliable architects and engineers. At Greenfield Build & Renovate, we work closely with several architectural practices in Clonmel and can coordinate the entire process from initial design through planning and construction. This joined-up approach means fewer delays, fewer surprises, and a smoother build overall.