Extending a Terraced House

Extending a Terraced House

Get the Right Permission in Place Before Adding Space to Your Terrace

Terraced housing is as popular as it has ever been. But if you are planning an extension, it brings its own challenges in terms of the permissions you need.


Mention terraced housing and your mind probably turns to the streets of Victorian two up, two down properties that are still a common site in our towns and cities. That’s fair enough, but what many people fail to notice is that this style of construction is still very much in fashion today’s constructions.

More than a quarter of homes in the UK are terraced, and the past ten years has seen a surge in their popularity. Young couples often favour them as a first or second home, but whether they choose a traditional Victorian terrace or something that has been built far more recently, it’s not uncommon for the space to become a little crowded, particularly when two becomes three or four.

Adding an extension to your terraced house is an ideal solution. In particular, it makes more sense than selling and upsizing in these uncertain economic times, when nobody is sure what the property market is likely to do. However, there are some additional checks you need to make, in terms of taking the right party wall advice and obtaining planning permission before you begin.

Party Wall Agreements

The Party Wall Act of 1996 is designed to ensure that any work you do on your property does not undermine the structure of shared walls on the neighbouring properties. In a terrace, you have neighbours close by, and as well as being a legal obligation, the Party Wall Act helps ensure you keep on good terms with them.

If you are planning a full width extension that runs up to the neighbouring boundary, then you will certainly need a Party Wall Agreement. But even if it is narrower, you will still need one if you are digging foundations within three metres of their property. In other words, practically any extension to a terraced house will fall under the scope of the Party Wall Act.

Nine times out of ten, perhaps more, obtaining the necessary consent is simple. All you have to do is serve a Party Wall Notice that describes the proposed works. The neighbour must then respond in writing that they either consent or dissent. If they agree, you are good to proceed, but if they either dissent or fail to respond, you will have to appoint an independent surveyor to make a formal Party Wall Award.

Planning Permission

Many extensions fall within the “permitted development” rights of the householder, meaning they do not require planning permission. This is usually the case for rear extensions, provided they do not exceed four metres in height, they are within two metres of all boundaries and they do not increase the volume of the home by more than ten percent or 50m3, whichever is greater.

If your extension is outside these parameters (for example a full width extension) or if you live in a conservation zone, then you will definitely need to obtain planning permission. Given that this is a complex matter, you should always speak to your local planning office, even if you think it is a permitted development, to get a definitive answer.