Planning permission and building control are often mentioned in the same breath, but they are not the same thing. In Northern Ireland they are administered separately, usually by different teams in the same council. A project can need one, both, or neither.
This article explains the distinction and the situations homeowners typically face. It is general information, not a formal determination. If you are unsure, ask your council planning office and building control office before work starts. For planning advice, you can also speak to NI Planning Permission.
Two systems, two purposes
Planning permission is about whether development should take place, and in what form. Councils decide most local applications against the local development plan and other material considerations. Regional policy is set out in the Strategic Planning Policy Statement. nidirect is clear that if you build or develop land without the permission you need, the council may force you to put things right later, and it advises you to ask the planning office before you start.
Building control is about how the work is built. The Building Regulations (Northern Ireland) 2012 set technical standards for matters such as structure, fire safety, energy performance, accessibility, and the health, safety, welfare and convenience of people in and around buildings. nidirect describes these as technical standards covering most construction work in homes, and says you must tell the council about building work you want to do. District councils enforce the regulations through their building control departments. The Department of Finance is responsible for the regulations themselves.
One is not a substitute for the other.
When planning permission is needed
You generally need planning permission for development, including many building works and material changes of use, unless the work is permitted development or is not development at all.
nidirect lists examples of work that does need an application, including extending a flat or maisonette, dividing part of your house into a separate home, using a garden building or caravan as a separate residence, building a separate house in your garden, and carrying out work that is prevented by a condition on an earlier permission.
You can make certain minor changes without a planning application if they fall within permitted development rights and meet every limit and condition. Those rights are set out in the Planning (General Permitted Development) Order (Northern Ireland) 2015, which has been amended from time to time, including in 2026. The current official text, and your council, should always be checked. Rights are restricted or removed for some properties, including listed buildings and many works in conservation areas and Areas of Outstanding Natural Beauty. Typical householder examples include some rear extensions and some outbuildings, each with their own limits. We cover extensions in Do I need planning permission for an extension in Northern Ireland?. Garden rooms are dealt with in more detail by NI Planning Permission.
If you want written confirmation that a proposal is lawful, you can apply for a certificate of lawfulness through the NI Planning Portal (Mid Ulster District Council uses its own system). That is optional, but it can be useful when you sell the house.
When building control approval is needed
You should assume that most structural or services work to a home needs a building control application unless an exemption clearly applies. The Department of Finance states that if you intend to erect, alter or extend a building, install services, fittings or works, or materially change the use of a building, you must first seek approval from your district council. That may involve full plans or, for certain domestic work, a building notice, together with the appropriate fee.
Council guidance, including Ards and North Down Borough Council’s note on work that requires approval, gives useful examples. Applications are commonly needed for a new building, an extension or alteration, a material change of use, a loft or garage conversion, a new or replacement septic tank, structural alterations (such as removing a chimney breast or opening up rooms), and new services such as heating, a stove or boiler, new sanitary appliances, or a heat pump.
There are exemptions. The Building Regulations (Northern Ireland) 2012, Schedule 2, sets them out in law. In outline, and subject to detailed conditions, they can include certain detached single-storey buildings of no more than 30 square metres with no sleeping accommodation, certain smaller sheds of no more than 15 square metres, and certain ground-level conservatories, porches and open carports within stated size limits. Exemptions are technical. A heated garden room used as habitable space, or any building that contains sleeping accommodation, will often fall outside them. Your local building control office can confirm whether a full-plans application or a building notice is appropriate.
Common projects: one, both, or neither?
The pattern below is a starting point only. Always check both offices.
- A typical house extension. Often needs building control. Planning permission is also required unless it falls entirely within permitted development. Speak to extension contractors and, where needed, an architect or structural engineer.
- A loft or garage conversion. Commonly needs building control. Planning permission depends on the works. See loft and garage conversions.
- A garden room or outbuilding. Planning depends on the Class D permitted development limits and the use (a separate residence is not permitted development). Building control depends on size, construction, proximity to boundaries and whether the building contains sleeping accommodation.
- Re-roofing. Planning may not be needed for a like-for-like re-cover, but can be required if the shape or a designated area is affected. Building control may be needed if the structure, weatherproofing or insulation is affected. See How to choose a roofer in Northern Ireland.
- A new boiler, stove, electrical installation or bathroom. Often a building control or competent-person issue. Planning is less commonly required, unless flues, external alterations or a listed building are involved. Use suitably qualified heating engineers, electricians and plumbers.
- A new house, or a shop converted to a dwelling. Planning permission and building control approval are both typically required.
How to apply, and why the completion documents matter
Planning applications for most councils, and for the Department, are submitted through the Planning Portal. Mid Ulster District Council has its own system. nidirect notes that a council should make a decision within eight weeks, though larger or more complex cases can take longer.
Building control applications are made to your district council, with further information on Building Control NI. Keep decision notices and the building control completion or approval document. Buyers’ solicitors routinely ask for them.
If you are planning a project in Belfast, Lisburn and Castlereagh or another council area, you can post a job or browse builders once you know which approvals you need. For planning questions, start with your council or NI Planning Permission.
Sources
- nidirect, Planning permission – when to apply; The planning system and development management; What Building Regulations protect
- Department for Infrastructure, New Planning Portal
- The Planning (General Permitted Development) Order (Northern Ireland) 2015
- Department of Finance, Building Regulations in Northern Ireland; The Building Regulations (Northern Ireland) 2012, Schedule 2
- Ards and North Down Borough Council, Work that requires Building Control Approval