Do I Need A Party Wall Agreement For An Extension? | Checkatrade
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Do I need a party wall agreement for an extension?

Planning an extension? You may need a Party Wall Agreement. Learn about building without an agreement, party wall act surveyors and Party Wall Awards.

If you live in a terraced or semi-detached house, you’ll be aware that you share at least one wall with a neighbour. This shared wall is called a party wall and usually, this isn’t an issue unless the walls are very thin. If you’re planning an extension, then you may be wondering if you need a party wall agreement.

As an extension is a big project, you’ll need to get a party wall agreement before getting started. A party wall agreement is a legal document where your neighbour gives their consent for you to start construction without any issues. That’s the best-case scenario but, your neighbour may not be happy for you to go ahead, in which case you’ll need a party wall award (more on this later).

Rules for building without a party wall agreement

reaching party wall agreement with neighbourBefore you come to an agreement with your neighbour, you’ll need to serve them with a party wall notice at least two months prior to starting works. Planning an extension can be an exciting process but if your neighbour won’t give their permission for construction, this can throw a spanner in the works. In this case, you may be wondering about building without a party wall agreement.

First, let’s look at the process a little closer. If your neighbour doesn’t consent or respond to your party wall notice, you’re classed as in dispute. At this point, you can either try reasoning with your neighbour or take further action.

Your neighbour may also send a counter-notice to you. This will outline any changes to works that they’re unhappy with. If you agree to these changes, you may be able to come up with a modified party wall agreement.

Alternatively, if you’re not able to come to an agreement you’ll need to hire a party wall act surveyor. They’re an impartial professional who decides whether or not your project can go ahead. They’ll also decide on the details of the job, including when your extension can go ahead and how it can be built. Once they make a decision, they’ll issue a party wall award.

Building without a party wall agreement definitely isn’t recommended. In fact, your neighbour could get an injunction stopping your extension from being built. You also won’t be able to apply for a party wall award if you build without an agreement.

Do you need a party wall act surveyor?

A party wall act surveyor is only needed when you fail to come to an agreement with your neighbour. You’ll also need to pay for the surveyor to come to a party wall award which may not be in your favour. If this does happen, you’ll have the opportunity to appeal the decision.


What is covered by a party wall award?

party wall agreement for extensionA party wall award is a detailed legal document covering how, when and what you’re allowed to build. It should cover:

  • Access details
  • Work hours
  • Damages and how these will be repaired
  • Noise considerations
  • Surveyors’ fees
  • Compensation
  • Security
  • Insurance for the contractors

Do you need a party wall agreement for a loft conversion?

Loft conversions like extensions are a big project that requires a lot of construction to take place. So, if you share a wall with a neighbour, you do need a party wall agreement for a loft conversion.

Do you need a party wall agreement for a detached house?

Many people don’t realise that in certain cases you may need a party wall agreement for a detached house as well as terraced or semi-detached properties. This really comes down to how close your home is to your neighbours. If your property is within 3 – 6 metres of your neighbours, you’ll need a party wall agreement.

Can you get a party wall agreement without a surveyor?

Yes, but you’ll need to ensure it’s a proper, detailed document covering all the essential considerations. You’ll still need a surveyor if you and your neighbour are in dispute.

Which tradesperson should I use?

If you need a party wall award, you’ll need to hire a qualified party wall act surveyor.

Finding a trustworthy party wall act surveyor

It can be frustrating if you’re unable to reach a party wall agreement with your neighbour, but this doesn’t mean you won’t be able to proceed with your extension. You will however need to find a qualified party wall act surveyor to make a decision either way.

Unsure how to find a trustworthy party wall act surveyor? Try our free search feature. Simply add your postcode to see professionals recommended by your neighbours. All of our members pass thorough checks so you can be safe in the knowledge that your tradesperson is trustworthy and qualified.

Once you have a party wall agreement in place, you’ll need to find a local contractor to take on the construction of your extension. Remember, our search feature is the quickest and easiest way to find tradespeople in your area. And we’re so confident in our members that we offer a guarantee in the unlikely event something goes wrong with your job (T&Cs apply).

How much does a party wall surveyor cost?

If you’re unable to reach a party wall agreement with your neighbour, you may be curious as to how much a party wall surveyor costs. The price will depend on the complexity of your project, the size of your home and a few other factors.

To learn more including average prices, take a look at our party wall surveyor cost guide.

How much does an extension cost?

Adding an extension can completely transform your home, giving you extra living space and allowing you to alter the layout to best suit your lifestyle. Extensions are a great investment, with average prices starting from £37,500.

If you’d like to know more about extension prices and important considerations, read our house extension cost guide.

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