Planning permission in Northern Ireland: a homeowner’s guide
Do you need planning permission? The decision table
Start here. The table below covers the projects NI homeowners ask about most. “Permitted development” means the work is allowed without a planning application, provided you stay inside the limits and the property is not in a designated area. One thing to fix in your head before you read on: planning permission and Building Control approval are two separate processes. Most building work needs Building Control approval from your council whether or not it needs planning permission, and we cover that in the NI Building Regulations guide.
Source: Planning (General Permitted Development) Order (Northern Ireland) 2015, Schedule Part 1, and nidirect “Planning permission, when to apply”. These are the general positions for a house outside a designated area. If your home is a flat, is listed, or sits in a conservation area or area of outstanding natural beauty, assume permission is needed and check with your council before you design.
What decides whether you need permission
Five things determine the answer, and they stack. Get any one of them wrong and a job you thought was permitted development turns into an enforcement problem later.
- Whether it is a house or a flat. Permitted development rights apply to houses. They do not apply to flats or maisonettes at all, so any external change to a flat needs permission.
- Whether the property is designated. Listed buildings, conservation areas and areas of outstanding natural beauty all have reduced permitted development rights. Work that would be permitted on an ordinary house often needs an application here, and sometimes a separate consent on top.
- Size and position against the PD limits. The permitted development limits are specific, measured numbers, set out in the table further down. A rear extension 200 mm too deep, or an outbuilding sited in front of the house, is no longer permitted development.
- Whether it creates a new home or a new use. Splitting a house into flats, building a separate dwelling in the garden, or turning a garden room into somewhere someone lives is a material change of use and always needs permission.
- Whether your rights have been removed. A council can remove permitted development rights for an area with an Article 4 direction, and a previous planning permission can carry a condition that removes them for your specific house. New-build estates often have such conditions.
The NI rules UK-wide guides get wrong
Most planning advice online is written for England, and a fair amount of it is simply wrong for Northern Ireland. The framework looks similar, but the law, the decision-maker and the fast-track routes are different. The biggest practical trap: there is no “larger home extension” prior-approval route in NI. In England you can build a single-storey rear extension up to 8 metres on a detached house through prior approval. In NI, the moment you go beyond the permitted development limit you need a full planning application.
Source: Planning (General Permitted Development) Order (Northern Ireland) 2015 against the Town and Country Planning (General Permitted Development) Order 2015 for England, with the Republic of Ireland exempted-development position from Citizens Information. England and ROI columns are comparison anchors; the NI figures are the ones to act on.
What is permitted development in NI?
Permitted development is work you can carry out without a planning application, within set limits, governed in Northern Ireland by the Planning (General Permitted Development) Order 2015. Stay inside every limit in the table below and your project needs no planning permission.
These are the actual limits from the NI permitted development order. Stay inside all of them and the work needs no planning application. Go beyond any one of them and it does. The single most common mistake is the rear extension limit: in NI it is 4 metres beyond the rear wall for a detached house and 3 metres for any other house type. If a guide tells you 3 metres regardless of house type, it is wrong for a detached home, and we have seen that error in plenty of UK-wide content.
Source: Planning (General Permitted Development) Order (Northern Ireland) 2015, Schedule Part 1, Classes A to I, cross-checked against Belfast City Council’s “Residential extensions and alterations” guidance. Every limit above is removed or tightened for listed buildings and inside conservation areas, areas of outstanding natural beauty, World Heritage Sites and National Parks, and where an Article 4 direction or a planning condition applies. If in any doubt, apply for a certificate of lawful development and get it in writing.
How do you apply for planning permission in NI?
If your project does need permission, this is the route. Almost all householder work is a “local” application, decided by your council rather than by the Department for Infrastructure.
- Talk to your council planning office first. Every NI council offers an informal pre-application view. A short conversation or email before you spend money on drawings can save a wasted application.
- Get drawings prepared. You will need existing and proposed drawings, normally from an architect or architectural technician. The same drawings serve the Building Control application and the builder’s quotes.
- Submit through the NI Planning Portal. Applications and the fee go through the NI Planning Portal, which routes to your council. The householder fee is £347.
- Validation. The council checks the application is complete and the fee is correct. An underpaid or incomplete application is returned, which costs you weeks.
- Neighbour notification and consultation. Neighbours are notified and the application is published for comment, usually for at least 21 days.
- Assessment and site visit. A case officer assesses the proposal against the local development plan and visits the site.
- Decision. Approval, usually with conditions, or refusal. If refused, you can amend and resubmit, or appeal to the Planning Appeals Commission.
How much does planning permission cost in NI in 2026?
A householder planning application in Northern Ireland costs £347 in 2026. A certificate of lawful development, which confirms your work is permitted development and needs no permission, is £307, and a full application to build a new single house is £1,035.
NI planning fees are set centrally by the Department for Infrastructure and are the same across all 11 councils. They rose on 1 April 2025 and usually move every April, so treat these as a 2026 snapshot and confirm the live figure on the Planning Portal before you submit. These are the council fees only. They do not include your drawings, an architect or architectural technician, or the separate Building Control fee. If your project is an extension, our single-storey extension cost guide breaks down the build budget that sits on top of these fees.
Source: Planning (Fees) (Amendment) Regulations (Northern Ireland) 2025, which substitute Part 2 of Schedule 1 to the Planning (Fees) Regulations (Northern Ireland) 2015, and the Department for Infrastructure planning fees overview. For comparison, the equivalent domestic application fee in the Republic of Ireland is €34 (Citizens Information), which is the single biggest cost difference a cross-border homeowner notices.
How long does planning permission take in NI?
The statutory target for a local application is 15 weeks, but the real average is about 19 to 20 weeks across the 11 NI councils. The reality is longer than the target. The Department for Infrastructure’s NI planning statistics put that average across 2024/25 and into 2025/26, with only three of the 11 councils inside the 15-week target. Simple householder applications with no objections often clear faster, but build your timeline around the real average, not the target, and add the Building Control timeline on top, since that is a separate approval.
Source: Department for Infrastructure, Northern Ireland Planning Statistics annual and quarterly statistical bulletins (2024/25 and 2025/26), published via infrastructure-ni.gov.uk and the Northern Ireland Executive.
Listed buildings, conservation areas and AONBs
If your home is listed, in a conservation area, or in an area of outstanding natural beauty, treat the permitted development table above as not applying and assume you need permission. The detail:
- Listed buildings. Almost any alteration, inside or out, needs listed building consent in addition to any planning permission. Permitted development for extensions does not apply within the curtilage of a listed building.
- Conservation areas. Permitted development is cut back. Roof alterations and dormers, for example, are not permitted development at all in a conservation area, and cladding and some outbuildings are restricted.
- Areas of outstanding natural beauty. Similar restrictions, with tighter limits on outbuildings and on extensions beyond the side or principal elevation.
You can check whether a property is listed or in a conservation area through nidirect’s conservation areas advice and finding a listed building pages, and your council planning office will confirm it.
What happens if you build without planning permission?
If you build without planning permission in Northern Ireland, the council can take enforcement action for up to five years after the work is substantially completed, and the problem usually resurfaces when you try to sell.
The risk of building without permission is rarely an inspector on the doorstep the next morning. It is the slow, expensive version. Under the Planning Act (Northern Ireland) 2011, a council generally has five years from the date unauthorised building work was substantially completed to take enforcement action. But the problem usually surfaces when you sell. NI conveyancing solicitors ask for evidence of planning approval and Building Control completion as standard. Without it, a buyer can cut their offer, insist on a retrospective application or a certificate of lawful development, or pull out. A retrospective application can also be refused, which leaves you having to undo completed work.
The clean way to remove the doubt before you build is a certificate of lawful proposed use or development, which costs £307 and gives you a formal council decision that your work is permitted development and needs no permission. On a borderline project it is cheap insurance.
The costs people forget
The £347 fee is the small part. The line items homeowners miss are these.
- Drawings and professional fees. An architect or architectural technician to produce the existing and proposed drawings, typically several hundred to a few thousand pounds depending on the project. A planning consultant if the case is contentious.
- Building Control, separately. Planning permission does not cover construction standards. The Building Control application to your council is a separate process with its own fee, covered in our Building Regulations guide.
- Discharging conditions. Most approvals come with conditions. Some have to be formally discharged, with supporting information, before or during the build.
- No Party Wall Act in NI. Northern Ireland has no Party Wall Act, unlike England and Wales. Where you build up to a shared boundary you still need written agreement from the neighbour and, ideally, a pre-build condition survey to avoid a dispute later.
- Time. The processing period is a real cost. Factor 15 to 20 weeks for the decision, plus Building Control, into when work can actually start.
Frequently asked questions
Conor writes the NI building and renovation cost benchmark guides for NI Trades. He draws on a civil-engineering background and on quotes from working FMB, OFTEC and NICEIC tradespeople across Northern Ireland to keep the price ranges realistic. He holds a BEng (Hons) in Civil Engineering from Queen’s University Belfast.