Party walls
How much notice do you need to give under the Party Wall Act?
Short answer
At least one month for a new wall on the boundary (section 1) and for excavation near a neighbour's building (section 6). At least two months for work to an existing party wall (a party structure notice, section 3). Work can start sooner only if the neighbour agrees in writing.
The Act sets no maximum. Party structure notices and excavation notices stop having effect if the work has not begun within 12 months of service and is not prosecuted with due diligence. Section 1 has no equivalent lapse wording. gov.uk's statement that notice must be given "between 2 months and a year" before work starts is wrong for sections 1 and 6.
The periods, side by side
| Notice | Section | Minimum notice | If the neighbour says nothing for 14 days | When it stops working |
|---|---|---|---|---|
| New party wall or party fence wall astride the boundary | 1(2) | One month | No consent. You may only build the wall wholly on your own land, at your own expense (1(4)). Not a dispute | No lapse wording in section 1 |
| New wall wholly on your own land, up to the boundary | 1(5) | One month | No reply is required. The booklet says that unless the neighbour objects, work may start after the month. Any dispute goes to surveyors (1(8)) | No lapse wording in section 1 |
| Party structure notice, for work under section 2 | 3(2)(a) | Two months | Deemed dispute (5) | Ceases if not begun within 12 months and not prosecuted with due diligence (3(2)(b)) |
| Excavation within 3 m or 6 m | 6(5) | One month | Deemed dispute (6(7)) | Ceases on the same terms (6(8)) |
| Counter notice from the neighbour, asking for extra work | 4(2)(b) | Served within one month of your party structure notice | If you do not consent within 14 days, deemed dispute (5) | Not applicable |
If an owner on whom a party structure notice or a counter notice has been served does not serve a notice indicating his consent to it within the period of fourteen days beginning with the day on which the party structure notice or counter notice was served, he shall be deemed to have dissented from the notice and a dispute shall be deemed to have arisen between the parties.
Section 6(7) uses the same words for excavation notices. Section 1 works differently. Silence on a notice for a wall astride the boundary is not a dispute. It simply means you have no consent, so the wall must go wholly on your side.
If, having been served with notice described in subsection (2), an adjoining owner does not consent under this subsection to the building of a party wall or party fence wall, the building owner may only build the wall (a) at his own expense; and (b) as an external wall or a fence wall, as the case may be, placed wholly on his own land, and consent under this subsection is consent by a notice served within the period of fourteen days beginning with the day on which the notice described in subsection (2) is served.
The "2 months to a year" error
gov.uk's guide Party walls and building work, on its "When and how to tell them" page, says notice must be given "between 2 months and a year" before work starts. It still said so when we checked on 28 September 2026. It is wrong in three ways:
- Line of junction notices (section 1) and excavation notices (section 6) need one month, not two.
- "A year" is not a maximum notice period. The Act has none. The 12 month figure is when a party structure or excavation notice ceases to have effect, and only if the work has also not been prosecuted with due diligence (sections 3(2)(b) and 6(8)).
- Section 1 contains no lapse provision at all. The government's own explanatory booklet treats a section 1 notice as "only valid for a year", which is guidance, not the wording of the Act. The Act's 12 month limit in section 1 is on something else: the right to place projecting footings under the neighbour's land runs from one month to twelve months after service (section 1(6)).
The explanatory booklet, which the same gov.uk guide links to, gives the periods correctly: two months for party structure notices, one month for line of junction and 3 or 6 metre notices.
A party structure notice shall (a) be served at least two months before the date on which the proposed work will begin; (b) cease to have effect if the work to which it relates (i) has not begun within the period of twelve months beginning with the day on which the notice is served; and (ii) is not prosecuted with due diligence.
Counting the days
The 14 days run from, and include, the day the notice is served. A party structure notice served on 1 March gives the neighbour until 14 March to consent. If no consent arrives, a dispute is deemed to have arisen from 15 March. The earliest the work can begin, without written agreement to start sooner, is two months after service.
Keep proof of the date. Notices can be delivered in person or posted (section 15(1)), and emailed only if the recipient has said they will accept email and given an address (section 15(1A)).
Other time limits in the Act
| What | Period | Section |
|---|---|---|
| Notice before entering the neighbour's land to carry out work | At least 14 days, except in an emergency | 8(4) |
| Neighbour fails to appoint a surveyor after your written request | 10 days, then you may appoint one for them | 10(4) |
| Appeal against a party wall award | 14 days from service of the award, to the county court | 10(17) |
| Neighbour's objection to your account for shared work | One month from service of the account | 13(2) |
What this means for you
Serve notices early enough for the longest period that applies. A loft conversion with beams in the party wall needs two months; an extension on the boundary with deep foundations needs one month, or two if it also involves work to an existing party wall under section 2. Do not serve so early that the work cannot start within 12 months.
Parallel does not act as a party wall surveyor. On projects we design, we prepare the drawings that accompany the notices.
Sources
- Party Wall etc. Act 1996, section 1: new building on line of junction legislation.gov.uk
- Party Wall etc. Act 1996, section 3: party structure notices legislation.gov.uk
- Party Wall etc. Act 1996, section 4: counter notices legislation.gov.uk
- Party Wall etc. Act 1996, section 5: disputes arising under sections 3 and 4 legislation.gov.uk
- Party Wall etc. Act 1996, section 6: adjacent excavation and construction legislation.gov.uk
- Party Wall etc. Act 1996, sections 8, 10, 13, 15 and 22 legislation.gov.uk
- Party walls and building work: when and how to tell them gov.uk
- The Party Wall etc Act 1996: explanatory booklet, paragraphs 9, 23, 25, 29 and 47 gov.uk