What is a Party Wall?

When undertaking construction or renovation works that involve shared boundaries, many property owners in England and Wales encounter the term “party wall.” Despite being a critical legal concept in property law, especially under the Party Wall etc. Act 1996, the term is often misunderstood. This article offers a comprehensive explanation of what a party wall is, how it is defined under law, why it matters in construction and development, and what obligations it places on property owners.

Understanding the Party Wall: Legal Definition

A party wall is a shared wall or structure that separates and is jointly owned by the owners of adjoining properties. According to the Party Wall etc. Act 1996 (the Act), a “party wall” can take several forms:

1. A wall that forms part of a building and stands on land of different owners (more than just the foundation projecting over).

2. A wall that does not form part of a building but separates buildings belonging to different owners (a boundary wall used in common).

3. A party fence wall, which is a wall standing on the land of different owners but not forming part of any building, and used to separate adjoining lands.

Key Types of Party Walls

To determine if a wall is a party wall, you must understand the type of structure and its positioning. The Act recognises three main types:

Party Walls forming part of a building: These are walls built astride the boundary line and form part of one or more buildings. A classic example is a terraced house wall shared with a neighbour.

Party Fence Walls: These are freestanding boundary walls built astride the boundary line but not forming part of any building.

Party Structures: These include shared floors and ceilings between flats or maisonettes in a multi-occupancy building.

Why Party Walls Matter in Construction

Party walls are legally significant because of the rights and responsibilities they confer on adjoining owners. If one neighbour (known as the building owner) wants to carry out works affecting the wall, they must comply with specific notice procedures and obtain necessary consents from the other party (the adjoining owner).

Typical examples of works that may affect a party wall include:

Building a new wall on the line of junction.

Cutting into a party wall to insert steel beams or flashing.

Raising or thickening the wall.

Demolishing and rebuilding the wall due to structural defects.

Excavating near the foundation of a party wall or neighbouring structure.

The Party Wall etc. Act 1996: Overview

The Act provides a statutory framework for preventing and resolving disputes relating to party walls, boundary walls, and excavations near neighbouring buildings. It applies across England and Wales and came into force on 1 July 1997.

The key objectives of the Act are to:

Define what constitutes a party wall.

Establish procedures for giving notice of works.

Set out dispute resolution processes through surveyors.

Protect the rights of adjoining owners.

Ensure that damage is avoided or appropriately compensated.

The Act requires you to serve a Notice before starting works and allows the adjoining owner to either consent or dissent — with dissent triggering a formal dispute resolution process involving surveyors.

When Must You Serve a Party Wall Notice?

A building owner must serve a formal Notice under three scenarios:

1. Works on an existing party wall – including repairs, raising the height, cutting into it, or demolishing and rebuilding it.

2. Construction on the line of junction – when building a new wall astride or up to the boundary.

3. Excavation within 3 or 6 metres of a neighbouring structure and below the depth of its foundations.

Notice periods vary depending on the work:

Two months' notice for works to a party structure.

One month's notice for new walls on the boundary or excavation.

If the adjoining owner consents in writing, the works can proceed. If they dissent, the parties must appoint surveyors to resolve the matter and issue a legally binding Award.

What is a Party Wall Award?

An Award is a document prepared by one or more surveyors that determines:

What works are allowed.

How they will be carried out.

What protections must be in place for the adjoining owner.

Who pays for the work and surveyor costs.

The award ensures fairness and clarity and is enforceable in court. Either party can appeal the award within 14 days in the county court if they believe it was made improperly.

Rights and Responsibilities of Owners

Building Owners’ Rights:

Carry out specified work to the party wall, party structure, or foundations.

Access the neighbour’s land with notice to carry out works.

Building Owners’ Duties:

Serve correct notice.

Avoid unnecessary inconvenience.

Compensate for any damage.

Comply with any party wall award.

Adjoining Owners’ Rights:

Consent or dissent to proposed works.

Appoint their own surveyor.

Require security for expenses.

Claim compensation for damage.

Common Misunderstandings

“It’s my wall - I can do what I want.” Incorrect. If it is a party wall as defined under the Act, you cannot lawfully carry out works without notice - even if you built it originally.

“Party walls only apply to terraced houses.” False. Work to a flat, semi-detached house, and even commercial buildings can require Notice under the Act.

“There’s no need for a surveyor if we agree.” Not entirely accurate. While agreement avoids a dispute, a formal record like a Schedule of Condition is strongly advisable to prevent arguments over damage later.

What Happens if You Ignore the Act?

Failure to comply with the provisions of the Act can result in:

Injunctions stopping the work.

Court action and liability for damages.

Delays to the project.

Increased costs, including legal fees and remedial works.

The Role of Surveyors

When a dispute arises, both parties typically appoint surveyors under section 10 of the Act. These surveyors are not advocates but must act impartially. If the two surveyors cannot agree, they appoint a third surveyor who makes the final decision.

Surveyors ensure that:

The works are properly assessed and documented.

Damage is prevented or rectified.

The rights of both parties are respected.

They also determine costs and responsibility for payment of the award.

Practical Examples

Loft conversion: Inserting steel beams into a shared wall to support a new floor or roof structure.

Basement excavation: Digging below neighbouring foundations within three or six metres.

Rear extension: Building a wall astride the boundary or cutting into the existing party wall.

All these require appropriate notices and potential agreements or awards.

Conclusion: What is a Party Wall and Why It Matters

A party wall is not just a physical structure - it represents a legal relationship between neighbours that must be handled with care and precision. Under the Act, property owners have a statutory duty to notify, consult, and, if necessary, resolve disputes through an agreed framework.

Understanding what a party wall is, and knowing when and how the Act applies, can help homeowners, developers, architects, and surveyors avoid unnecessary conflict, delay, and legal costs.

If you are planning work near a shared wall or boundary, it is wise to consult a qualified surveyor experienced in neighbourly matters early in the process to ensure compliance and maintain good neighbourly relations.

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If you are planning work that is covered by the Act, or if you have received notice of work from a neighbour and want advice on how best to protect your property please contact: