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What is the Party Wall Act?

terraced cottages with party walls
(Image credit: getty images)

If you’re looking to carry out building work on a terraced or semi-detached house or flat, then it is likely you will have a shared wall with a neighbouring property.

The Party Wall Act prevents building work undertaken by one neighbour undermining the structural integrity of shared walls or neighbouring properties. It is also designed to avert and resolve potential disputes with neighbours.

Will it Affect my Plans to Renovate?

If you live in a semi, terrace, flat, or your detached home is sited within close proximity to neighbouring houses, it might.

The key things to remember are which walls constitute as ‘party walls’ and the type of work subject to the Act.

Walls and other built elements include:

  • floors and ceilings between flats
  • shared boundary walls, such as those between semis and terraced homes
  • any other walls which touch the boundary are covered.

Type of work

More extensive work is covered by the Party Wall Act. This includes:

  • converting a loft which includes cutting into boundary walls to support new beams
  • underpinning
  • inserting a damp-proof course
  • increasing the thickness
  • demolishing and rebuilding a party wall
  • extending above a storey which lies on the boundary
  • building a new wall for an extension, for example, up to or on the boundary
  • excavation work for new foundations, subject to condition (see below). You’ll need to assure your neighbour of the safeguards in place to protect their foundations.

Superficial tasks are not included, such as:

  • fitting shelves
  • replastering
  • wallpapering
  • electrical rewiring

If you plan to undertake any work covered by the Act, you’ll also have to give ‘Notice’ of the commencement of work to your neighbour.

You must give Notice under the Party Wall Act if you’re excavating for new foundations deeper than the foundations of your neighbours’ home, within three metres of the boundary, or within six metres if a 45° will be formed between the bottom of your new foundations and those belonging to your neighbour.

You don’t need planning permission for your plans to serve notice.

How Do I Give ‘Notice’?

If your project is covered by the Act, you give Notice with a letter setting out your intentions, sent to all the owners of every neighbouring property affected.

A sample letter is included within The Party Wall Act booklet (download or order your copy at

Remember to include all the key information, including:

  • the date the Notice is served
  • the date work will start
  • all parties’ names and addresses
  • a description of the proposed work

If you don’t do this, your Notice will be invalid.

When Do I Need to Give Party Wall Notice?

Once complete, present this, together with a copy of the Act and explanatory booklet, to your neighbour two months before starting. (If you are excavating near a neighbouring building then you need to give at least one month’s notice.)

Your neighbour will have 14 days to provide written approval or rejection. Let them know a template is available for both options in the explanatory booklet.

  • If they provide approval, your Notice will be valid for a year to complete work
  • If they reject or do not respond within 14 days, then you’re deemed to be in dispute

What Happens if the Neighbours Object?

Talk to your neighbours and explain your plans in detail to reach an agreement.

If approval is impossible, then you will have to assign an ‘agreed surveyor’ or two surveyors to prepare a Party Wall Award. This ‘Award’ covers:

  • the work that can be carried out
  • how the works will proceed
  • timings
  • measures for preventing damage
  • the payment of surveyors’ fees
  • the current condition of both properties
  • most importantly, costs payable to the adjoining owner if damage occurs.

What Does a Party Wall Surveyor Do?

In short, party wall surveyors help mitigate risk to all parties, and ensure that projects can progress without delay.

If you correctly serve notice on your neighbours and damage occurs, any disputes over that damage will be dealt with by surveyors rather than at common law.

Is a Party Wall Notice Mandatory?

If things turn sour with your neighbour and they suspect that the work being carried out will adversely affect their home, they can seek a court injunction to stop you from continuing.

If you haven’t obeyed the Act and you cause major damage to your neighbour’s property, the judge can award compensation for any loss or damage resulting from the works, including legal costs.

An approved Notice is the only way to prevent this.

Cost of a Party Wall Notice

For a straightforward job outside London with an adjoining owner dissenting to the works, fees are likely to be in the region of £1,000-2,000 plus VAT.

Fees will depend on the nature and complexity of the work being undertaken as well as the number of adjoining owners. And it is not always the case that the person instigating the work will pay all parties’ fees.

To get an accurate quote, consult a RICS accredited surveyor. It’s also worth consulting them if you have had a Party Wall Notice served on you.