Beginner's Guide

What is the Party wall act?

The party wall act provides the necessary framework for preventing and resolving disputes the act was introduced to minimise disputes by making sure property owners use surveyors to determine the way and time in which certain works are carried out.  The regulations apply to any building works that may affect the party wall/boundary, and excavations near neighbouring buildings.

If you live in a semi-detached property and wish to carry out building works, the last thing you want is an illegitimate claim for damages from your neighbour. Equally, if your neighbour is carrying out work you would want your property protected from damages and any unnecessary nuisances. 

What is a party wall?

A party wall Is a wall that stands on the land of two owners and forms part of a building, or a wall that is on one owner’s land but is used by two or more owners to separate their buildings. As mentioned before if you live in a semi-detached house, you will share a party wall with your neighbour, however, party walls are not limited to walls that directly separate properties.  Some examples of party walls are;

  • Internal and external walls that divide semi-detached and terraced houses.
  • The floors and ceilings between flats.
  • Garden walls, also known as Party Fence walls.

Works that invoke the Act.

Three main types of works invoke the act;

  • Excavation and Construction Near Neighbouring Buildings: This usually happens when the Building Owner wants to build an extension or a new building near or on the boundary line with an Adjoining Owner's property. The Party Wall Act provides guidelines for excavations within a certain distance of a neighbouring building or structure, as these activities can impact the structural integrity of nearby properties.
  • Alterations to Party Walls: This includes changes made to the shared wall between two properties, often referred to as a "party wall". Such alterations could include cutting into the wall to insert beams for a loft conversion, removing chimney breasts from the wall, or even demolishing and rebuilding the wall.
  • Construction of New Walls on the Boundary Line: This involves the construction of a new wall at the boundary line between two properties. The new wall could either straddle the boundary line (a "party wall") or be built entirely on the land of the Building Owner but up to the boundary line. This is a common occurrence when the Building Owner wants to build an extension or a new structure on their land.

It's important to remember that all of these works typically require notice to be served on the Adjoining Owners under the Party Wall Act, and that disputes can be resolved by appointed surveyors if parties cannot agree.

Some of the most common works that invoke the party wall act are;

  • Building a new wall on the boundary line between two properties.
  • Removing or altering an existing party wall or party fence wall.
  • Excavating near a neighbouring property, such as for a new foundation or basement
  • Carrying out work on a shared chimney stack.
  • Installing new beams or lintels that extend into a neighbouring property, generally occurs during extensions and loft conversions. 
  • Building a new structure that is attached to a neighbouring property.
  • Carrying out work on a boundary wall or fence, where the work will affect the foundation or stability of the wall or fence.

Party wall notices.

A Party Wall Act Notice is a document that is served to the adjoining owners informing the adjoining owners of the planned works. 

The notice will expire within a year but once served, the Adjoining Owners have 14 days to provide a written agreement, or otherwise, the notice will automatically fall into dispute. The notice will also fall into dispute if the Adjoining Owners refuse to agree.

Section 1 of the act covers buildings on the line of junction. Essentially this section gives the building owner the right to build a wall/fence/structure on or astride the boundary line. If you wish to build on the line of junction, you are required to serve notice to the adjoining owner one month before the start of construction. This notice is required for building both on the boundary line and stride the boundary line. If the adjoining owner consents to the notice the wall/fence will be built in a position that is agreed on, or half on the land of the two owners. If the adjoining owner does not consent to the notice then the wall/fence must be built entirely on your land at your own expense. When it comes to the issue of who pays for the wall/fence, it is decided by who benefits from the wall the most and not its position relative to the boundary line.  When building a wall astride the line of junction, you must compensate the adjoining owner for any damages caused to their land.  It is important to undertake a schedule of condition report to record the adjoining owner’s property before works commence. 

Section 3 of the act covers works to an existing party wall that severs both the building owner and the adjoining owner. This section covers works such as loft extensions, ground extensions, chimney breast removals etc.  Section 3 is one of the most common notices served under the act, almost all work will fall under this notice. Section 3 must be served at least two months before the works commence. The adjoining owner must consent within 14 days otherwise there is a dispute and party wall surveyors must be appointed.

Note that some works on a party wall may be so minor that they are not covered by the act. For example, installing wall units or shelving, cutting into a party wall to add or replace electric wiring, removing old plaster etc. The key point to consider is if the works might have possible consequences for the structural strength of the party wall. 

Section 6 of the act covers the excavation and construction of foundations for a new building or structure, within 3 - 6 meters of any part of a neighbouring owner building or structure, where any part of the works will go deeper than the neighbour’s foundations.  You must inform the adjoining owners by serving a notice of at least one month before the works commence.  The notice must state if you plan to strengthen or safeguard the foundations belonging to the adjoining owner. Plans and sections must also accompany the notice.

The Role and Powers of a Party Wall Surveyor

Party wall surveyors are responsible for advising clients on their rights and responsibilities under the Party Wall Act. They explain the act, the requirements, and how it applies to their project.

Party wall surveyors are also responsible for preparing and serving party wall notices to adjoining property owners. The notices signal the intention to carry out work and can include details of the proposed work and the expected duration.

Party wall surveyors can conduct surveys to determine the condition of the party wall, including its structural integrity and whether the proposed work will impact it.

If an adjoining owner dissents from the notice, a building surveyor can appoint an impartial party wall surveyor to act on behalf of both parties and ensure the work is carried out in compliance with the Party Wall Act.

Where necessary, building surveyors can prepare party wall agreements to determine the proposed work's terms and conditions.

Sometimes, disputes may arise between adjoining property owners during the party wall process. Surveyors can act as mediators to help resolve disputes.

Overall, the Party Wall surveyor plays a crucial role in ensuring compliance with the Party Wall Act, protecting the rights and interests of all parties involved, and ensuring that the work is carried out safely and to a high standard.

When it comes to the fees of the Party Wall Surveyor, the building owner undertaking the works will pay all costs associated with drawing up the award, if the works are solely for the building owner’s benefit. In cases where work is necessary due to a defect or need for repair, the adjoining owner may have to pay costs. 

Party Wall Awards

A party wall award is the final piece of documentation in the party wall process that ensures that the adjoining owners and building owners are adequately protected if damage occurs from the building works.

A party wall award can determine:

  • The time frame and manner for executing the works.
  • A right for building owners to execute work under the party wall act.
  • The rights of the building owner to execute works, form a neighbouring property.
  • Imposing time restrictions for access-related matter, for example, such as only working between 9 am to 5 pm, where access is required.
  • Requiring temporary protective measures for support of weathering.
  • Security for expenses.

The award is a final legally binding document unless it is altered or modified by a court appeal. Each adjoining owner has 14 days from the service of the award to appeal to the court against the award. 

What can happen if the Act is not followed by the BO?

Whilst there is no fixed penalty for failing to serve a notice, an adjoining owner would have various legal actions they would be able to commence against a building owner.

For Example, Mr Nelson planned a loft conversion for his home, which involved cutting into his neighbour’s property, Mrs Whites’ property. Mr Nelson was not aware of the party wall act and proceeded without serving any party wall notices to Mrs White.

Upon hearing the sound of heavy machinery, Mrs White became very concerned about the stability of her property. She contacted a party wall surveyor who advised her about the Party Pall Act and the need for proper notice.

Mr Nelson learnt that he had failed his obligations under the Party Wall Act and was in breach of the law. This jeopardised the construction of his loft conversion and created tension with Mrs White. 

As a result of the legal proceedings, Mr Nelson was ordered to stop the construction works until the Party Wall notices were served and proper precautions were put in place to protect Mrs White’s property. Mr Nelson was also Liable for the legal costs. 

The Party wall surveyor examined the proposed works and undertook a schedule of conditions to assess any potential risks. Through communication mediated by the surveyors Mr Nelson and Mrs White came to an agreement. The Party wall award outlined the precautions that need to be taken during the construction process.  


Complying with the Party wall act is crucial for anyone planning building works involving shared walls/boundaries and excavations near neighbouring buildings. By understanding the act’s purpose, the types of work covered and the importance of serving proper notices, you can ensure a smoother process and maintain good relationships with your neighbours. When faced with disagreements, it is wise to seek the advice of a party wall surveyor to ensure compliance with the act. By Adhering to the requirements of the act you can protect the interests of all parties involved and avoid any illegitimate claims.  The party wall act will help you achieve legal compliance but also provide a smooth construction experience, benefiting both you and your neighbours.

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We are a team of party wall surveying experts based throughout London and the surrounding areas. Here, we share informative property survey blogs created by industry experts.



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