Many house extensions can go ahead without a full planning application, but not all, and getting it wrong can be expensive. This guide explains how the rules work in general and what to check if you live in Newport or elsewhere in Wales.
Important: planning rules differ between England, Wales, Scotland and Northern Ireland, and they change from time to time. Newport is in Wales, so Welsh rules and Newport City Council apply. Treat this article as an overview and always confirm the position for your own address with the council or a planning professional before building.
What is permitted development?
Permitted development (PD) rights let homeowners carry out certain types of work without applying for planning permission, provided the project stays within set limits. For extensions those limits typically cover:
- the depth the extension projects from the rear or side of the house
- the height of the extension, including eaves and ridge
- the proportion of the garden that is covered by buildings
- the materials, which should normally be similar in appearance to the existing house
- position: extensions to the front of the house generally need permission
Two-storey extensions, extensions close to boundaries and extensions to the side are usually more tightly limited than a single-storey rear extension.
When you are likely to need planning permission
Planning permission is commonly required when:
- your house is in a conservation area, a National Park or another designated area, where PD rights are reduced
- the property is a listed building (you will also need listed building consent for most work)
- the flat or maisonette you own does not have PD rights, which is usually the case
- PD rights were removed by an earlier planning condition or an Article 4 direction
- the extension is larger than PD limits allow, or sits forward of the front of the house
- you have already extended the house and the total is over the limits
Newport and Wales specifics
Some parts of Newport are conservation areas, for example around Caerleon, and these can change what you may build without permission. Householder permitted development in Wales is set by the Welsh Government and may differ from the England rules you read about on many national websites, so use Welsh guidance and speak to Newport City Council. The council's planning team can tell you whether a proposal needs an application and whether any restrictions apply to your street.
Lawful Development Certificates: proof you did not need permission
If you believe your project is permitted development, you can apply for a Lawful Development Certificate (LDC). It confirms in writing that the work is lawful. It is not compulsory, but it is very useful when you later sell the house, because buyers' solicitors often ask for evidence.
How long does a planning application take?
For a householder application, councils aim to make a decision within eight weeks of a valid application, although complex cases can take longer. Allow additional time to prepare drawings and any supporting documents beforehand. See our guide to the whole extension timeline.
Planning permission is not the same as building regulations
Even when no planning permission is needed, an extension almost always needs building regulations approval, which covers structure, insulation, fire safety and drainage. They are separate processes. Read more in building regulations for house extensions. If you share a boundary wall with a neighbour, a separate party wall agreement may also be needed.
Practical steps
- Check whether your property has any restrictions (conservation area, listing, Article 4, previous planning conditions).
- Look at what you want to build and measure depth, height and boundary distances.
- Ask the council or a planning consultant to confirm whether permission is needed.
- If it is, prepare drawings and submit a householder application.
- Consider talking to neighbours early, because objections can delay decisions.
Talk to a local builder early
Abron Contracting works on home extensions in Newport and can help you think through your project before you spend money on drawings. Get in touch or call 01633379170.
Frequently asked questions
Can I build an extension without planning permission?
Often, yes, if it falls within permitted development limits and your property has not lost those rights. Limits cover size, height, position and materials, so check your exact proposal first.
Do I need planning permission for a single-storey rear extension?
Many single-storey rear extensions fall within permitted development, but depth and height limits apply and are different for detached, semi-detached and terraced houses. Confirm the current rules for your address.
Are the rules the same in Wales as in England?
Not necessarily. Planning is a devolved matter, and Welsh permitted development rules can differ from the English ones. In Newport, check with Newport City Council.
What is a Lawful Development Certificate?
It is an official confirmation from the council that proposed or existing work is lawful without planning permission. It is optional but helpful when selling.
What happens if I build without permission?
The council can take enforcement action, which may require you to alter or remove the work, and it can cause problems when you sell. It is much safer to confirm the position first.
