A Client’s Guide to Planning Permission
A practical guide for homeowners and small developers: when you need planning permission, how the process works week by week, what it costs, and why applications fail.
In 2023, 13.2% of all planning applications in Ireland were invalidated before a planner ever read them. Wrong newspaper, defective site notice, a missing drawing. Of the applications that did get assessed, most refusals came down to the same handful of issues, and nearly all of them were visible before the application was lodged.
That is the most useful thing to understand about the Irish planning system: it is not a lottery. It is a rules-based process, and the rules are published. If your proposal complies with the Development Plan, the paperwork is right, and the impact on your neighbours has been dealt with in the design, you will very probably get permission. This guide walks through how it works, using Dublin City Council as the main example, though the process is the same in every local authority.
Do You Need Planning Permission at All?
Not all work needs permission. The Planning and Development Regulations set out classes of exempted development, and for homeowners the most important one covers rear extensions.
A single or two storey extension to the rear of a house is generally exempt where:
The total floor area of all extensions, including anything built previously (even by a former owner), does not exceed 40 square metres
No more than 12 square metres of that is above ground floor level for a terraced or semi-detached house, or 20 square metres for a detached house
At least 25 square metres of private open space remains behind the house
Height limits and window separation distances are met, including a minimum of 11 metres between any above ground floor rear window and the boundary it faces
The 40 square metre limit is cumulative, and this catches people out constantly. If the house already has a 25 square metre extension from the 1990s, you have 15 square metres left, not 40. Demolishing part of the original house to build the extension can also take the works outside exemption, as can anything that materially affects the external appearance of the front of the house. Attic conversions, porches, garden structures and change of use each have their own rules.
If there is any doubt, ask the council for a Section 5 Declaration. For a fee of €80 the local authority will formally confirm whether your proposal is exempt, usually within four weeks. It is a small cost against the alternative: building first and discovering later, typically at the point of sale, that the works are unauthorised and need retention permission or removal.
The Development Plan Decides Before You Apply
Every local authority publishes a Development Plan, revised on a six year cycle, and it is the yardstick against which your application will be measured. The Dublin City Development Plan 2022 to 2028 runs to over a thousand pages, but only two parts matter for most projects.
The first is the zoning map, which sets out what uses are acceptable where. A proposal that conflicts with zoning will almost certainly be refused, and no amount of design quality will rescue it.
The second is the development standards: the specific numerical and qualitative rules for your project type. For a Dublin mews house, for example, the Plan requires a minimum lane width of 4.8 metres and a 22 metre separation between opposing windows, relaxable only where the design demonstrably protects privacy. We wrote about those standards in detail in our guide to building a mews house in Dublin. Extensions, apartment schemes and commercial conversions each have equivalent standards covering privacy, daylight, scale, parking and open space.
Reading the proposal against the Plan is the first thing we do on any project, before design work starts. The single most common cause of refusal is a straightforward conflict with a published policy, which means it is also the most avoidable.
The Process, Step by Step
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Before lodging, you can request a pre-planning meeting with the council under Section 247 of the Planning and Development Act. You present the proposal at concept stage and the area planner gives an informal view: what they can support, what will cause difficulty, what additional reports they will expect. The advice is not binding, but it is the cheapest design review you will ever get. On contentious or unusual sites we treat it as essential. Redesigning at sketch stage costs days; redesigning after a refusal costs months.
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Two notices are required before you lodge: a site notice on the land, and a notice in a newspaper from the council's approved list. The application must be lodged within two weeks of the newspaper notice appearing, and the site notice must remain legible in place for five weeks after the application is received.
These are strict statutory requirements, and they are where that 13.2% invalidation rate comes from. A notice in the wrong newspaper, a site notice positioned where it cannot be read from the public road, or a mismatch between the notices and the drawings will see the application returned, and the whole notice process starts again.
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The application itself comprises the statutory forms, the fee (€34 for a domestic extension, €65 for a new house), six copies of the drawings, the site location map, and whatever supporting reports the proposal warrants: a design statement, daylight and sunlight assessment, drainage details, or a conservation report where a protected structure is involved. The council checks it for completeness before it enters the system.
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The council issues one of three decisions: a grant, a grant subject to conditions (the most common outcome), or a refusal with stated reasons. Any party, including a neighbour who made a submission, then has four weeks to appeal to An Coimisiún Pleanála, formerly An Bord Pleanála. An appeal reopens the entire case, not just the point under dispute, and can add a year or more to the programme. If no appeal is lodged, the final grant issues after the four weeks expire.
A standard permission lasts five years. Construction cannot start the day the grant arrives: for most projects a Commencement Notice under the Building Control Regulations must be lodged at least 14 days before starting on site, and the BCAR certification process runs from there. Planning is one consent; building control is another.
Why Applications Fail
Refusals cluster around four causes, and all four can be managed.
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The proposal breaches zoning or a written standard. Avoidable by reading the Plan first and testing the design against it before anyone falls in love with a scheme that cannot be permitted.
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Overlooking, overshadowing and overbearing scale are the workhorses of both refusals and third party objections. The answer is evidence, not assertion. A daylight and sunlight assessment that shows compliance with the BRE guidelines gives the planner objective grounds to grant, and gives an objection much less to stand on.
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Development Plans increasingly demand design quality in terms a planner can assess: response to context, materials, architectural composition. A thin application with minimal drawings reads as risk, and planners refuse risk.
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Invalid notices, inconsistent drawings, missing reports. Entirely mechanical, entirely avoidable, and responsible for more delay than any other single cause.
What It Costs and How Long It Takes
For a typical home extension requiring permission, allow for the €34 application fee, a few hundred euro for the newspaper notice and site notice, and professional fees for the architect and any specialist reports. The realistic timeline from lodgement to final grant is 12 weeks where there is no RFI and no appeal: eight weeks to decision, four weeks for the appeal period to expire. Add design and pre-application time in front of that, so from first meeting to permission, five to eight months is a sensible planning assumption for a straightforward domestic project. Complex sites, protected structures and appeals extend it.
These are not costs to resent. Measured against a construction budget, the planning stage is a small fraction of total spend, and it is where the risk of the entire project is either designed out or locked in.
Where the Architect Earns Their Fee
It should be clear by now that most of the value in the planning process is delivered before the application is lodged: the Development Plan analysis, the pre-application consultation, the design that resolves neighbour impacts rather than arguing about them, the assessments that pre-empt an RFI, and the paperwork that gets validated first time.
That work is not visible in the final drawings, but it is the difference between a 12 week consent and an 18 month saga. It is also why we treat planning not as a hurdle after design but as a constraint that shapes design from the first sketch. An RIAI registered architect is regulated, insured and accountable for exactly this judgement.
If you are planning a project in Dublin or elsewhere in Ireland, get in touch. We are happy to look at your site and give you an honest view of what is achievable and what the planning risks are before you commit.
David Williams & Co. is an RIAI registered architecture studio in Smithfield, Dublin 7. We design housing, schools and public buildings.