As a firm of RICS Chartered Surveyors, one of the most common questions we get from people looking to extend their homes is “Do I need a party wall agreement for my works?”. This is to be expected because whilst virtually everyone knows about planning and Building Regulations, there is generally much more confusion about the Party Wall Act. In this article, we will try to help answer that question, and hopefully by the end of it you will know if your works need a party wall agreement.
Note: During this article we will refer to both “party wall agreements”, and “party wall awards”. The two terms are interchangeable. The more formal terminology is “party wall award”, but “party wall agreement” is also commonly used.
Under the Party Wall etc. Act 1996 (the ‘Act’), certain types of building work must be formally notified to your neighbours, and if they dissent to that notice, the matter then progresses to a party wall award.
However, understanding when an agreement is required, and when it isn’t, can be confusing. The answer typically depends on the type of work being carried out, rather than its scale or cost.
There are three broad categories where a party wall agreement (more formally, a Party Wall Award) is likely to be necessary:
1. Works Directly to a Party Wall or Party Structure
This is the situation most homeowners associate with the Act.
If your plans involve cutting into a shared wall, underpinning it, increasing its height, inserting steel beams, removing chimney breasts, or otherwise altering the structure, notice must be served on any affected adjoining owners.
Once notice is served, your neighbour has three possible responses:
- They can consent, allowing work to proceed without an award.
- They can dissent and appoint a surveyor, triggering the need for an award.
- They can dissent and appoint the same surveyor (an agreed surveyor) to act impartially for both parties, who will, independently and impartially, prepare a party wall award.
In practice, most structural works to a shared wall will lead to a party wall award being required. The award sets out how the works will be carried out, protects both parties’ rights, and includes a schedule of condition of the neighbour’s property before the works start in the event that there are any reports of damage.
What to ask yourself:
- Am I carrying out works to a party wall or structure?
- If so, do those works involve cutting into it, raising or underpinning it, cutting away from it, or otherwise altering or exposing it?
If you answered yes to either of the above, then you will likely need to serve party wall notices, and in the event of a dissenting neighbour, you will need a party wall agreement.
2. Excavations Close to a Neighbouring Property
Even if you never touch the party wall itself, you may still need an agreement.
Excavations within 3 metres (and in some cases 6 metres) of a neighbour’s structure fall under the Act if they are deeper than the existing foundation. This commonly applies to:
- Rear extensions
- Side extensions
- Basement works
- New foundations for garden rooms or outbuildings
These situations often cause confusion because the work appears to be entirely on the building owner’s land. Nonetheless, the law is clear: if the excavation meets the technical thresholds, notice must be served and a party wall award may follow.
What to ask yourself:
- Am I excavating within 3m of an adjoining property or structure (not including fences)?
- If so, are the excavations deeper than the bottom of its foundations? The answer is usually yes unless the structure is new, or part of a tall building like a block of flats.
- If I am not excavating within 3m, but am excavating within 6m, am I using particularly deep foundations, such as piles?
If the answer to any of the above is yes, then a party wall notice will be required, which will lead to a party wall award in the event of a neighbour dissenting.
3. Construction of a New Wall at the Boundary Line
If you intend to build a new wall right up to, or astride, the boundary, the Act will typically apply.
Building on the boundary (a “Line of Junction Notice”) gives neighbours certain rights of consent or dissent. Building up to the boundary can also trigger the need for notification and, depending on your neighbour’s response, a formal party wall award.
It is important to mention that this type of notice is required even when you are building wholly on your own land. This sometimes causes confusion, but this rule is in place to avoid a neighbour being suddenly surprised by the construction of a new wall right on their boundary.
Under the Act, you can request to build a wall partly on your neighbour’s land, effectively creating a new party wall. However, you can only do this if they consent to the notice, otherwise it must be built entirely on your own land. A neighbour may consent to having a wall built partly on their land in the event that they may later want to use that wall for an extension of their own – something they would not be able to do if the wall is built entirely on your land. Read more about building on the boundary line.
Common Scenarios Where Homeowners Ask This Question
A few examples help illustrate when the requirement applies:
- Loft conversions: Cutting into the party wall to install steel beams → agreement required if the neighbour dissents.
- Rear extension: New foundations within 3 metres of the neighbour → likely agreement required.
- Chimney breast removal: Alteration to a shared wall → agreement required if neighbour dissents.
- Garden outbuilding: If the foundation depth triggers the excavation rules (3m / 6m) → agreement may be required.
- Internal refurbishments: Purely non-structural works → no party wall agreement needed.
What If My Neighbour Consents?
This is an important point that causes misunderstanding.
If you serve notice and your neighbour consents in writing, no party wall award is needed and the works can proceed. However, consent does not remove your obligations: you must still undertake the works carefully and avoid causing unnecessary inconvenience or damage.
For larger or more complex projects, many homeowners still prefer to have an award prepared, even with a consenting neighbour, simply because it provides a clear record and reduces the risk of disputes later.
Why the Party Wall Award Matters
When required, a party wall award:
- sets out how the works will be carried out
- often includes method statements or drawings
- records the condition of the adjoining property before works begin
- defines access arrangements
- provides a framework for handling any damage, should it occur
It protects both parties, not just the neighbour. Building owners often find significant value in having a clear agreement in place once contractors are on site.
Summary: Do You Need a Party Wall Agreement?
You may need one if:
- You are cutting into, altering, or working directly on a shared wall
- You are excavating near a neighbour’s property or structure
- You are building a wall on or next to the boundary
You won’t need one if:
- The works are entirely internal and non-structural
- You are not affecting shared structures or excavating near them
- Your neighbour has consented to the notice
If you are unsure whether your project requires a party wall agreement, or you need assistance serving notices or appointing a surveyor, feel free to contact us for straightforward, professional advice.
