How Do I Know If I Need A Party Wall Agreement?

How Do I Know If I Need A Party Wall Agreement?
Disclosure: Clicking on links on this page may earn us a small commission. This helps us continue to produce free content and doesn't affect the price you pay.
If you are searching for an answer to the question ‘How do I know if I need a party wall agreement?’ then the short answer is that you probably do.

But what is a party wall agreement?

Essentially, any building work that takes place on your property that may affect a shared wall with a neighbour will need to have an agreement in place.

The party wall is the wall that you share with neighbours so terrace and semi-detached properties will have a shared wall.

Also, a garden wall that runs along a shared boundary may also be considered to be one.

It’s worth bearing in mind that the Party Wall Act applies to any work carried out directly to a structure or party wall but this also includes a floor between properties.

So, if you want to carry out work to your flat, then you should ask a surveyor whether the work will come under the law which means you must then issue notices to your neighbours.

Do I need a party wall agreement for an extension?

Any foundations with more than 3 meters will need a party wall agreement.

Put simply, an agreement is required if excavations are taking place on yours or on a neighbour’s property.

Usually, this means that any foundations that will be three metres deep will need one.

And if the foundations are going to be six metres deep, if you are piling for example, then you will certainly need an agreement.

The party wall agreement will also enable the installation of a loft conversion as well as a damp proof course and also for creating new foundations which may be necessary for building an extension.

You must serve the notice at least one or two months before you begin working, and this timescale will depend on the work you are carrying out.

For instance, you’ll need two months’ notice if you are planning to:

  • Underpin a wall;
  • Insert a steel beam;
  • Remove a chimney breast.

You’ll need at least one month’s notice before excavations or work begins for any plans to build on a neighbour’s boundary line or close to their property.

Is a party wall agreement necessary?

A party wall agreement is a legal protection both for you and your neighbour.

It may not be necessary to have a party wall agreement in place – a surveyor will tell you more – but should something go wrong with any works, then you will have legal protection with an agreement.

Essentially, if you want to carry out any work that involves a party wall, then you really should seek a written agreement from your neighbours – they are also known as ‘adjoining owners’ because they will be affected.

Before beginning work, you must:

  • Deliver a notice to all of your affected neighbours;
  • You also should not begin any work until the agreement has been agreed to;
  • Sometimes these agreements are known as ‘party wall awards’.

Also, you can serve a party wall notice before you have obtained planning permission, but you’ll need to be confident that permission will be given so you can start work as soon as possible.

Serving a notice is relatively inexpensive with most surveyors charging around £100 inc VAT for serving the notice.

It’s also worth bearing in mind that under the Act, a neighbour can’t give consent without you serving a notice and even if they say they will consent to any work you want to carry out, this notice should still be served. They then have 14 days to give their consent in writing.

What is the purpose of a party wall agreement?

The purpose of a party wall agreement is to notify your neighbours that work will commence so you should give them at least two months written notice before this work begins.

A party wall agreement is not only paperwork.

The agreement will be necessary for any work affecting a boundary or party wall and a neighbour has 14 days to respond after the notice has been served to give their agreement.

This essentially means that they are happy for the building work to proceed, providing that you will then put right any problems that may occur. Or, they may decide to refuse permission.

Can a party wall agreement be refused?

Should your neighbour refuse consent means you will need to appoint an impartial surveyor who will act as an independent third party for you and your dissenting neighbour.

It’s this surveyor who will produce the party wall award to detail the works being proposed and the schedule of conditions.

The surveyor will also take notes and images of any cracks and provide this evidence for you and your neighbour. The big issue when a neighbour refuses permission is that the independent surveyor may add up to £1,000 to any building work you are planning.

Since the surveyor’s rates could be up to £200 an hour, this is a potential expense that needs to be factored in.

It’s also worth noting on this question of whether a agreement can be refused that should your neighbour fail to respond within 14 days then there’s a legal position to consider.

This lack of response will indicate that they have dissented so you will need a party wall award for the work to proceed. This is clearly stated in the Act.

Do not mistake your neighbour’s silence for consent!

If you hear nothing, then your surveyor will get in touch with your neighbour to issue a ten-day notice letter which informs them that they have 10 days for appointing their own surveyor or one will be appointed to act on their behalf. This comes under Section 10(4) of the Act.

How long does a party wall agreement last?

A full year is the validity of the Party Wall Award.

What it comes to understanding how long a party wall agreement will last, then it is clearly stated in law.

The Party Wall Award will be valid for 12 months from the date that the award – not the notice – is given. This means that the building’s owner must begin their proposed works within 12 months of that date.

Failure to begin work within this timescale means that work cannot proceed afterwards and you’ll need to begin the process again.

Can you have a retrospective party wall agreement?

It is not possible under the law to have a retrospective party wall agreement put in place. Though under section 10 of the Act, both neighbours will need an independent surveyor or you will need two surveyors to put the agreement together and both owners must agree to this.

Usually, a retrospective agreement is put in place once the works have either been fully completed or have been partially carried out.

The agreement is used to deal with any allegations or claims made of damage. The agreement will then offer clarity on the works carried out and include terms such as ‘as-built’

It’s also unlikely that planning permission will be given retrospectively and surveyors will only serve a notice if they believe there is a chance of it being authorised.

The Party Wall Act makes no reference to a retrospective notice or award and usually any consequences such as damage being made to an owner’s adjoining property will probably need to be settled in court unless the neighbours cannot agree to a solution.

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

Yes! A loft conversion requires a party wall agreement.

The answer to the question, ‘Do I need a party wall agreement for a loft conversion’ is yes. There is no doubt that you will always need an agreement in place before any work begins. That is because:

  • You will need RSJs: These are steel beams that the builder will use to support the structure;
  • The issue is that they will need to rest inside the party wall;
  • You need an agreement despite the beams resting on your half of the party wall;
  • The agreement will help avoid any potential disputes once the work begins.

Essentially, having anagreement in place is an excellent idea for both you and your neighbours, particularly if you have a good relationship with them. The agreement will give them the security of knowing that any complications or issues that may arise from any building work will be rectified by you.

Receiving a party wall notice

It’s also worth appreciating that it will be a good idea having a discussion with your neighbour before they receive a notice as a surprise.

That’s because the paperwork can appear to be very formal, which could lead to bad feelings between you and your neighbour when a casual conversation about your building plans beforehand will help smooth this path.

For anyone who really is wondering whether they need an agreement in place, then the answer is unmistakably ‘Yes’ because the Act not only protects your neighbour from any work you and your builders carry out, but it also helps to protect you when there’s an agreement between you and your neighbour.

More information

For more help and information about whether you need a party wall agreement, there’s a very useful page on the .Gov site that explains more.


  • Steve Lumley

    Steve Lumley has years of experience writing about property. His output has covered everything from property investment, news for landlords and student tenants to articles on how to run a successful portfolio and starting out as a property investor. He has also written several books on the subject.

    View all posts
  • Paul James

    Paul James, is a marketing expert with a passion for property. As well as being a property investor, Paul has also worked within the marketing departments of some of the UK’s leading estate agents. Paul is the founder of Property Road.

    View all posts
Guide To Selling With An Online Estate Agent

Selling With An Online Estate Agent Guide


The Complete Guide To Selling With An Online Estate Agent

When you subscribe to our email newsletter. Plus, receive a 7-day crash course on how to get higher offers on ANY type of property.

You can unsubscribe at any time.
See our Privacy Policy.