How to Serve Party Wall Notices for a London Extension or Loft Conversion

**The three types of work that trigger the Party Wall etc. Act 1996**:

The Party Wall etc. Act creates three separate notice requirements for different types of work:

**1. Section 1 Notice — New wall at or along the line of junction (boundary)**:

• A Section 1 notice is required where you propose to build a new wall astride the boundary line (half on your land, half on the neighbour's land) or directly on the boundary line. This notice is used for:
• •A new party wall where none existed before
• •Building on or along the common boundary where you have not previously agreed the use of the boundary

In practice, Section 1 notices are less commonly needed for London residential extensions because the new extension wall is typically built entirely within the homeowner's own land (set back from the boundary, or on the inner face of an existing boundary wall). However, where a side return extension is built directly against the neighbour's boundary, Section 1 may be relevant.

*Section 1 notice timing*: 1 month's written notice required before work starts.

**2. Section 3 Notice — Works to an existing party wall or party structure**:

• A Section 3 notice (party structure notice) is required where you propose to carry out work directly to an existing party wall or party floor — the shared structural element between the two properties. This notice is used for:
• •Cutting into the party wall to insert joist hangers or beam bearings for a loft conversion floor
• •Cutting into the party wall to install a steel beam (where the beam bears on the party wall)
• •Raising the height of the party wall (where the extension or loft is higher than the existing shared wall and the party wall must be raised)
• •Building into or forming pockets in the party wall
• •Pinning timbers into the party wall
• •Underpinning the party wall foundation (for basement projects)
• •Weatherproofing the party wall (where work exposes the face of the party wall on the neighbour's side)

*Section 3 notice timing*: 2 months' written notice required before work starts.

For a typical London loft conversion, Section 3 notices are almost always required — the new loft floor joists (or joist hangers for them) must bear on or connect to the party wall on both sides. Similarly, for a rear extension where a structural steel beam is installed in the rear wall (which may be or adjoin the party wall), Section 3 may be required depending on the structural arrangement.

**3. Section 6 Notice — Excavations within 3m or 6m of a neighbouring structure**:

• A Section 6 notice is required where you propose to:
• •Excavate within 3m of a neighbouring structure (typically the adjacent house) to a depth greater than the neighbour's foundations
• •Excavate within 6m of a neighbouring structure where the excavation would cut a line drawn at 45° from the bottom of the neighbour's foundations

For London rear extensions, Section 6 notices are very commonly required. The foundations of the extension are almost always within 3m of the party wall and the footings of the adjacent house — and the new extension foundations must be dug deeper than the adjacent house's shallow Victorian strip footings (to reach adequate bearing depth, or to comply with Building Regulations).

*Section 6 notice timing*: 1 month's written notice required before work starts. However, Section 6 is almost always served concurrently with Section 3 where both apply — and the more restrictive 2-month notice period effectively applies.

**Summary — which notices are required for common London project types**:

| Project type | Typical notices required | |---|---| | Rear extension (single-storey) | Section 6 (excavation within 3m); Section 3 (if beam bears on party wall) | | Rear extension (double-storey) | Section 3 (party wall raised) + Section 6 | | Side return extension | Section 1 or 3 + Section 6 | | Loft conversion (dormer, floor into party wall) | Section 3 (joist hangers or beam bearing on party wall) | | Basement conversion | Section 3 + Section 6 (underpinning) | | Structural opening in rear wall (no extension) | Section 3 if wall is party or adjacent to party wall |

**Number of neighbours to be notified**:

• In a London terrace:
• •Rear extension: typically both immediate neighbours (left side and right side) must receive Section 6 notices (both are within 3m of the excavations)
• •If the extension involves work to the party wall on one side only (e.g., a steel beam bearing on the left-hand party wall only), the Section 3 notice goes to the left neighbour only
• •For a mid-terrace loft conversion: both neighbours may need Section 3 notices (loft floor joists may bear on both party walls)
• •For a semi-detached house with one party wall: typically only the shared side neighbour receives notices

**The content of a party wall notice**:

• A party wall notice must contain the following information to be valid:
• •Your name (the 'building owner' — the person carrying out the works)
• •The address of the property where the works are being carried out
• •The full name and address of the neighbour (the 'adjoining owner')
• •Description of the proposed works
• •The proposed start date (and the notice period — confirming the notice meets the 1 or 2 month requirement)

The notice must be in writing. There is no prescribed form — a clear letter is acceptable. Notices can also be served via a party wall surveyor (the surveyor prepares and serves the notice on your behalf).

**How to serve the notice**:

• •By hand delivery (letter through the letterbox) — keep a photo of delivery
• •By first class or recorded post to the property address
• •In cases where the property is tenanted: the notice should go to the owner, not the tenant. Where the owner's address is unknown, service on the property address is generally acceptable

*Service on absent owners*: Where the adjacent property is uninhabited or the owner's whereabouts are unknown, after attempting service and documenting that the notice has been served by fixing it to the building, this may be accepted as valid service — but legal advice is recommended in this situation.

*Service on multiple owners*: Where the adjacent property is jointly owned (both owner names on the Land Registry title), the notice must be served on both owners.

**What happens after the notice is served — the three possible responses**:

*Response 1 — Consent (agreement)*:

The adjoining owner may respond in writing with consent to the proposed works within 14 days of receiving the notice. This is the simplest outcome — the works can proceed without the need for a party wall award. In practice, consent is common for routine loft conversions and extensions on straightforward terraced properties where the works are unlikely to cause damage.

Note: even with consent, it is best practice (and in many cases required by the Act) to have a Schedule of Condition prepared — a photographic and written record of the condition of the neighbouring property before the works start. This protects both parties — the adjoining owner has evidence of the pre-work condition; the building owner has evidence that any damage claimed was pre-existing and not caused by the works.

*Response 2 — Dissent (dispute), triggering party wall award*:

• If the adjoining owner dissents (or does not respond within 14 days of the notice), a dispute is deemed to exist. In this case:
• •Both parties must appoint party wall surveyors (or agree to use a single 'agreed surveyor')
• •Where each party appoints their own surveyor, the two surveyors work together to produce a Party Wall Award (also called the Award)
• •The Award is a legally binding document that describes: the works to be carried out; the access required; the times of working; any protective measures required; and the rights and responsibilities of each party
• •The Award also typically includes a Schedule of Condition of the adjoining property (prepared by the adjoining owner's surveyor before works start)

*Response 3 — Agreement not reached — third surveyor*:

Where the two party wall surveyors cannot agree on the terms of the Award, either surveyor may refer the matter to a Third Surveyor (who was agreed at the outset of the appointment). The Third Surveyor's Award is binding on all parties.

**Party wall surveyor fees**:

Party wall surveyors' fees in London vary — the market is not regulated for price, and fees range from very low (some surveyors offer fixed-price services for standard residential cases) to very high (for complex disputes or basement projects). Indicative fee ranges:

• •Building owner's surveyor fee (single party wall, standard residential): £600–£1,500
• •Adjoining owner's surveyor fee: typically paid by the building owner (the party doing the works) — approximately the same range as the building owner's surveyor
• •Agreed surveyor (single surveyor acting for both): £800–£1,800
• •Third surveyor referral: additional fee; typically £1,000–£3,000 depending on complexity
• •Schedule of Condition (standalone): £300–£600 per neighbouring property

For a typical London rear extension with two neighbours, the total party wall cost (building owner's surveyor + two neighbouring surveyors' fees) is commonly £1,500–£4,000 — this is the building owner's cost to budget for.

**Rights of access under the Party Wall Act**:

The Party Wall Act also confers a right of access to the adjoining property where the works cannot be carried out without such access — for example, where scaffolding must be erected on or above the neighbouring property to complete the roof of an extension. This right of access is subject to the terms of the Party Wall Award and the builder must give at least 14 days' notice before accessing the neighbouring property.

**The timeline for party wall notices in a typical London rear extension**:

Party wall compliance adds a mandatory minimum time to any project timeline — the notice period cannot be waived by the building owner:

• *Typical timeline*:
• •Day 1: Party wall notices served on all affected neighbours
• •Day 1–14: Response period — awaiting neighbour's consent or dissent
• •If consent within 14 days: works can start after the notice period has expired (2 months from serving a Section 3 notice, 1 month from a Section 6 notice)
• •If dissent (or no response within 14 days): surveyors appointed; Award drafted and agreed
• •Typical time from dissent to Award: 4–8 weeks for a straightforward project
• •Schedule of Condition (photography): carried out before works start, after Award is agreed
• •Works commence: after notice period + any Award

For a project targeting a start date, party wall notices should be served as early as possible — ideally immediately after planning permission is received (or as soon as PD status is confirmed, if no planning permission is needed). Waiting until the contractor has priced the job and the contract is signed before serving notices can easily cause a 2–3 month delay to the programme start.

**Common party wall mistakes in London extension projects**:

1. *Notices served too late*: Serving notices only a few weeks before the planned start date, without allowing the full notice period, is the single most common party wall mistake. Plan the notice period into the programme from the outset.

2. *Wrong section of the Act*: Serving only a Section 6 notice when Section 3 was also required (because the steel beam bears on the party wall). Both must be served — and the longer 2-month period applies where Section 3 is required.

3. *Not notifying all affected neighbours*: On a mid-terrace, not notifying both side neighbours when both are within 3m of the excavations.

4. *No Schedule of Condition*: Starting works without a Schedule of Condition of the adjoining property. If damage is claimed after the works, the absence of a pre-work condition record makes it much harder to demonstrate that the damage was pre-existing.

5. *Commencing before the Award is agreed*: Starting structural works before the Party Wall Award has been formally agreed and issued. The Award protects both parties — working without one exposes the building owner to a potential injunction sought by the neighbour.

6. *Selecting a surveyor based on price alone*: Party wall surveyors' quality varies widely. A surveyor who is slow to prepare the Award, or who produces an Award that is subsequently challenged, costs more in delay than their lower fee saves.

**Who appoints the party wall surveyors in a principal contractor arrangement?**

• The party wall process is the building owner's (homeowner's) legal responsibility — not the contractor's. The building owner must:
• •Serve the notices (or instruct a surveyor to do so)
• •Appoint a party wall surveyor if required
• •Pay both their own and the neighbouring owners' surveyor fees
• •Ensure the Award is in place before structural works commence

In practice, most good London contractors (and architects) will flag the party wall requirement during pre-construction discussions and recommend when notices should be served. Some principal contractors include party wall notice drafting as part of their pre-construction service. However, the legal obligation rests with the homeowner.