You must serve party wall notice at least two months before starting work covered by Section 2 (work to an existing party wall) and at least one month for Section 1 (new building on the boundary) and Section 6 (excavation) notices. Your neighbour then has 14 days to respond; if they dissent or fail to respond, surveyors are appointed to agree an Award.
If you're planning building work that affects a shared wall, boundary, or involves excavation near a neighbour's property, understanding party wall notice timelines is essential. Serving notice too late can delay your project by weeks or even months. This guide explains exactly when to serve each type of notice under the Party Wall etc. Act 1996, helping you plan your building project with confidence.
The Party Wall etc. Act 1996 sets out specific notice periods that building owners must observe before starting certain types of work. These aren't suggestions or guidelines; they're legal requirements. Getting them wrong doesn't just risk neighbourly relations; it can expose you to legal liability and significant project delays.
Understanding the Three Types of Party Wall Notice
Before examining the timelines, it's important to understand party wall requirements. The Act covers three distinct categories of work, each with its own notice requirements. The type of work you're planning determines which notice you need to serve and how far in advance.
Section 1 Notices: Building on the Line of Junction
A Section 1 notice applies when you intend to build a new wall at or astride the boundary line between your property and your neighbour's. This commonly arises when building an extension that will sit on the boundary, or when constructing a garden wall.
Under Section 1(2) and 1(5) of the Act, you must give your neighbour at least one month's notice before beginning the work. This notice period begins from when the notice is served, not from when you send it.
The notice must specify:
Your name and address
The nature of the proposed work
The date on which the work is intended to begin
Your neighbour (the 'adjoining owner') then has one month from receiving the notice to respond with a counter-notice under Section 1(3), which may indicate that they wish the wall to be built as a party wall astride the boundary (if you proposed building entirely on your land) or built entirely on your land (if you proposed a party wall).
Section 2 Notices: Work to Existing Party Structures
Section 2 notices cover work to existing party walls, party fence walls, or party structures. This is the most common type of notice served in practice, particularly for loft conversions, extensions, and renovation projects in terraced or semi-detached properties.
Under Section 3(2)(a) of the Act, you must give at least two months' notice before beginning work covered by Section 2. This longer notice period reflects the potentially more disruptive nature of work to shared structures.
Work that requires a Section 2 notice includes:
Cutting into a party wall to insert a beam or joist
Raising a party wall
Demolishing and rebuilding a party wall
Demolishing a shared garden wall (party fence wall) and building a party wall in its place
Cutting away projections (such as chimney breasts) from a party wall
Underpinning a party wall
The two-month notice period is the minimum required by statute. In practice, allowing additional time is often sensible, particularly for complex projects or where relationships with neighbours may require careful management.
Section 6 Notices: Excavation Near Neighbouring Buildings
Section 6 notices apply to excavation work near neighbouring buildings, even where no party wall exists. This section is frequently relevant for basement excavations, foundations for extensions, and significant landscaping work.
Under Section 6(5), you must give at least one month's notice before beginning excavation that falls within the scope of Section 6.
Section 6 applies in two circumstances:
The Three-Metre Rule: If you propose to excavate within three metres of a neighbouring building or structure, and that excavation will go below the level of the neighbour's foundations, you must serve a Section 6 notice.
The Six-Metre Rule: If you propose to excavate within six metres of a neighbouring building or structure, and that excavation will intersect a 45-degree line drawn downward from the bottom of the neighbour's foundations, you must serve a Section 6 notice.
The six-metre rule catches deeper excavations that might affect neighbouring foundations even though they're further away. This is particularly relevant for basement excavations in London, where significant depths are common.
Notice Period Summary Table
Notice Type |
Covers |
Minimum Notice Period |
Statutory Reference |
|---|---|---|---|
Section 1 |
New walls on or at the boundary |
1 month |
Section 1(2) or 1(5) |
Section 2 |
Work to existing party structures |
2 months |
Section 3(2)(a) |
Section 6 |
Excavation near neighbouring buildings |
1 month |
Section 6(5) |
What Happens After You Serve Notice?
Serving notice is just the first step in the party wall process. What happens next depends on how your neighbour responds.
If Your Neighbour Consents
The ideal outcome is that your neighbour provides written consent to your proposed works. If they do, and you complete the work without causing damage, the matter is concluded. No surveyor appointments are necessary, and no party wall award is required.
Consent should be in writing and should clearly state that the adjoining owner agrees to the works described in the notice. This written consent protects both parties should any dispute arise later.
If Your Neighbour Dissents
If your neighbour responds in writing stating that they do not consent to the works, or if they wish to protect their interests through a party wall award, a dispute is deemed to have arisen under Section 10 of the Act.
At this point, surveyors must be appointed. You and your neighbour can either:
Appoint an agreed surveyor: A single surveyor who acts impartially for both parties
Each appoint your own surveyor: Your surveyor and your neighbour's surveyor then work together (and may appoint a third surveyor if they cannot agree)
The surveyors will then prepare a party wall award, which is a legal document setting out the rights and responsibilities of both parties regarding the proposed works.
If Your Neighbour Doesn't Respond
Under Section 5 of the Act, if your neighbour does not respond to your notice within 14 days, a dispute is deemed to have arisen. This is known as "deemed dissent."
Deemed dissent does not mean your neighbour objects to the work. It simply means the formal party wall process must be followed. The practical effect is the same as if they had expressly dissented: surveyors must be appointed and an award must be made before work can begin.
This 14-day response period is important for your planning. If you serve a Section 2 notice, for example, the timeline might unfold as follows:
Day 0: Notice served
Day 14: If no response, deemed dissent arises
Days 14-60+: Surveyors appointed, award prepared
Day 60+: Two-month notice period expires; work can begin (assuming award is in place)
Building Your Project Timeline
Understanding the notice periods is only useful if you can integrate them into your overall project planning. Here's how to approach this.
Start with Your Target Start Date
Work backwards from when you want to begin construction. If you're planning to start a loft conversion on 1 June, and the work involves inserting steel beams into a party wall (requiring a Section 2 notice), you need to have served notice by 1 April at the latest.
However, this assumes everything proceeds smoothly. In practice, allowing more time is prudent.
Allow Time for the Award Process
If your neighbour dissents or doesn't respond, surveyors must prepare a party wall award before work can begin. While there's no statutory timeline for this, a straightforward award typically takes 2-4 weeks once surveyors are appointed. Complex matters can take longer.
For a Section 2 notice with a two-month notice period, you might plan as follows:
Month 1: Serve notice; wait for response; if no response within 14 days, appoint surveyors
Month 2: Surveyors prepare award; notice period continues
Month 3: Award in place; notice period expired; work can begin
This suggests serving notice at least three months before your intended start date for Section 2 work, even though the statutory minimum is two months.
Consider Multiple Notices
Many projects require more than one type of notice. A rear extension with a basement, for example, might require:
A Section 2 notice for work to the party wall
A Section 6 notice for the basement excavation
Possibly a Section 1 notice if building a new wall on or at the boundary
These notices can be served simultaneously, but you need to ensure all applicable notice periods have expired before the relevant work begins. The longest notice period effectively sets your timeline.
Factor in Planning and Building Regulations
Party wall matters are separate from planning permission and building regulations approval. You can serve party wall notices before obtaining these other approvals, but you cannot begin work until all necessary consents are in place.
A common approach is to serve party wall notices shortly after submitting planning applications, so the timelines run in parallel. This can significantly reduce overall project duration.
Common Timeline Mistakes to Avoid
In our experience as party wall surveyors, certain timing mistakes recur frequently. (See our FAQ for more common questions.) Being aware of these can help you avoid costly delays.
Starting Work Before the Notice Period Expires
This is the most serious timing error. Work begun before the relevant notice period has expired is technically unlawful, regardless of whether your neighbour has consented. Consent allows you to proceed without a formal award, but it does not shorten the statutory notice period.
If you start work prematurely, your neighbour can seek an injunction to stop the work. Even if they don't take legal action, you lose the protection the Act provides if a dispute arises later.
Assuming Consent Means You Can Start Immediately
Related to the above, some building owners assume that once their neighbour consents, they can begin work straight away. The Act does not support this interpretation. The notice periods exist to give adjoining owners time to consider the implications of the proposed work, and they apply regardless of the response.
Serving Notice Too Early
While it might seem prudent to serve notice as early as possible, notices served more than twelve months before work begins lose their validity. Notices cease to have effect if work does not begin within twelve months.
If your project is delayed beyond twelve months, you may need to serve fresh notices and restart the process.
Forgetting About Multiple Adjoining Owners
If your property adjoins multiple neighbours, you must serve separate notices on each affected adjoining owner. The notice periods run independently for each neighbour, so if one consents quickly and another doesn't respond, you'll be waiting for the deemed dissent process with the second neighbour even if the first has already agreed.
Special Circumstances Affecting Timeline
Emergency Work
The Act makes no specific provision for emergency work. If a party wall requires urgent repair to prevent collapse or other immediate danger, the practical approach is to carry out the necessary emergency work and regularise the position afterwards. However, this should genuinely be an emergency, not a way to circumvent the notice requirements.
Work by Agreement
Parties can agree to vary the statutory notice periods by written agreement. If both you and your neighbour are keen to proceed quickly and are comfortable with the proposed works, you can potentially shorten the timeline by mutual consent. This should be documented clearly in writing.
Leasehold Properties
Where the adjoining property is leasehold, you may need to serve notice on both the leaseholder and the freeholder, depending on the terms of the lease and the nature of the proposed works. This can complicate the timeline, particularly where the freeholder is difficult to contact or slow to respond.
Access Rights and Timeline Implications
Under Section 8 of the Act, building owners have a right of access to adjoining land for the purpose of executing work under the Act. However, this right must be exercised properly.
Section 8(4) requires you to give at least 14 days' notice before exercising a right of access to adjoining premises. This notice is separate from the Section 1, 2, or 6 notice that authorises the work itself.
If your work requires access to your neighbour's property (for example, to erect scaffolding or to execute work from their side of the wall), you must factor this additional notice requirement into your timeline.
Practical Steps for Getting Your Timeline Right
Based on the legal requirements and practical realities discussed above, here is a structured approach to planning your party wall timeline:
Identify all notifiable work: Review your plans and identify every element that falls within Section 1, 2, or 6 of the Act.
Identify all adjoining owners: Determine who needs to be served with notice. This may include multiple neighbours if your project affects more than one boundary.
Determine the longest notice period: If multiple notice types apply, the longest period (typically two months for Section 2 work) effectively sets your minimum timeline.
Add time for the award process: Assume that at least some adjoining owners will not consent, requiring surveyor appointments and an award. Add 3-4 weeks to your timeline for this.
Work backwards from your target start date: Count back the notice period plus the award process time from when you want to begin work. This tells you when to serve notice.
Build in contingency: Things rarely go exactly to plan. Adding an extra 2-4 weeks of contingency is sensible.
Example Timelines
Loft Conversion with Steel Beams
Target start date: 1 June
Work involves: Cutting into party wall to insert beams (Section 2)
Notice period: 2 months
Award process: Allow 3 weeks
Contingency: 2 weeks
Serve notice by: 15 February
Basement Extension
Target start date: 1 September
Work involves: Excavation below neighbour's foundations (Section 6) and underpinning party wall (Section 2)
Notice period: 2 months (Section 2 is the longer requirement)
Award process: Allow 4 weeks (basement work is more complex)
Contingency: 3 weeks
Serve notice by: 1 June
Garden Boundary Wall
Target start date: 1 April
Work involves: Building new wall on the boundary (Section 1)
Notice period: 1 month
Award process: Allow 2 weeks (simpler matter)
Contingency: 2 weeks
Serve notice by: 15 February
Key Takeaways
Section 1 notices (new walls on or at the boundary) require at least one month's notice.
Section 2 notices (work to existing party structures) require at least two months' notice.
Section 6 notices (excavation near neighbours) require at least one month's notice.
If your neighbour doesn't respond within 14 days, a dispute is deemed to arise, requiring surveyor appointments.
Factor in time for the award process (typically 2-4 weeks) when planning your project timeline.
Notices expire after 12 months if work hasn't begun.
Serving notice early is wise, but not more than 12 months before work is intended to start.
Need Help with Party Wall Notices?
Grey & Associates has been helping London homeowners navigate party wall matters since 2008. If you're unsure about notice periods, need assistance serving notices correctly, or require a party wall surveyor, we're here to help.