Not all Party Wall Notices are the same, and this is something that trips up a surprising number of people, including some who have prior experience of the party wall process but haven’t encountered every type of work the Act covers. Getting the right notice prepared and served correctly is one of the most fundamental parts of what we do at ALD Surveying, and understanding the difference between the three types is essential before any notifiable work begins.
The Party Wall etc. Act 1996 sets out three distinct types of notice, each applying to different categories of work. Using the wrong type, or serving it too late, can invalidate the notice entirely and expose you to legal risk.
Section 1: The Line of Junction Notice
The first is the Section 1 Line of Junction Notice. This applies when a building owner intends to build a new wall at the boundary line between two properties, or astride that boundary. It’s relevant when you’re not touching an existing party wall but are constructing something new that sits on or along the boundary line. The notice period for this type is one month, meaning it must be served at least one month before work is due to begin. This type of notice is common in scenarios like side extensions where a new boundary wall forms part of the build. If you’re planning something like this as part of a wider extension project, our coverage of extension-specific matters in Do I Need a Party Wall Notice for a House Extension? goes into further detail.
Section 3: The Party Structure Notice
The second type is the Section 3 Party Structure Notice. This is the most frequently encountered notice in residential party wall work and applies when the building owner intends to carry out works to an existing party wall or party structure. This includes cutting into the wall to insert beams or steel supports, raising or demolishing part of the wall, and making good or underpinning a shared structure. The notice period here is two months, which reflects the more significant nature of the works involved. Loft conversions and rear extensions are two of the most common triggers for a Section 3 notice, and we cover each of those scenarios in Do I Need a Party Wall Notice for My Loft Conversion? and Do I Need a Party Wall Notice for a House Extension? respectively.
Section 6: The Adjacent Excavation Notice
The third is the Section 6 Adjacent Excavation Notice. This applies when a building owner plans to excavate within three metres of a neighbouring structure where the excavation will go deeper than the neighbour’s foundations, or within six metres where the excavation line intersects with a 45-degree line drawn downward from the base of the neighbour’s foundations. Basement conversions and deep foundation work are the most common triggers. The notice period for this type is also one month. The Section 6 notice is sometimes underestimated in terms of its scope, and many homeowners assume excavation rules only apply to major groundworks when in fact even a relatively modest excavation close to the boundary of a semi-detached property can fall within the Act’s remit.
When More Than One Notice Applies
A point we always stress to clients is that more than one type of notice can apply to the same project. A basement conversion that involves cutting into the party wall, excavating close to the neighbour’s foundations, and potentially building a new wall along the boundary could conceivably require all three notices. In practice, the most common combination is Section 3 and Section 6, particularly for lower ground floor extensions and subterranean projects.
The consequences of serving the wrong notice or failing to serve one at all are worth taking seriously. Beyond the legal exposure, there’s the practical issue of works being halted mid-project if a neighbour decides to take formal action. At that point, the cost and disruption involved can far outweigh what it would have cost to get the notices right from the start.
Preparing the correct notices, serving them to the right parties, and managing the response process is exactly what a qualified party wall surveyor is there to do. For more information on what happens after a notice is served and how the Party Wall Award process works, take a look at Party Wall Notice vs. Party Wall Award: What’s the Difference?. Details of all the services offered by ALD Surveying can be found on our Party Wall Notices page.