Free Tool

Party Wall Calculator

Check whether your building project triggers the Party Wall etc. Act 1996 and find out which notices you need to serve on your neighbours. Answer a few questions about your project and get an instant assessment of your party wall obligations.

When do you need a party wall notice?

The Party Wall etc. Act 1996 requires you to notify your neighbours before carrying out certain types of building work. Three situations trigger the Act:

S.1
New wall on the boundary
S.2
Work to a shared wall
S.6
Excavation near neighbour

Multiple sections can apply to the same project. Each affected neighbour must be served individually.

Look up your property (optional)

Enter your address and we'll auto-detect your property type and shared boundaries from OS building data.

Check your project

If you are unsure, choose the boundary closest to where the building work will take place.

This includes inserting beams, removing chimney breasts, raising the wall height, or any structural alteration to a shared wall.

Count each property that shares a boundary or structure affected by your project.

Understanding the three sections

Section 1 — New wall

Applies when you want to build a new wall on or along the boundary line between your property and your neighbour’s. This is common with boundary garden walls and some extension foundations. Notice period: 1 month.

Section 2 — Shared wall

Applies when you are carrying out work to an existing party wall or party structure. This includes cutting in beams, raising the wall, removing chimney breasts, or underpinning. Notice period: 2 months.

Section 6 — Excavation

Applies when you are excavating within 3 metres of a neighbouring building to below their foundation level, or within 6 metres where the excavation intersects a 45-degree line from their foundations. Notice period: 1 month.

Need to serve a party wall notice?

If your project triggers the Party Wall Act, we can generate legally compliant notices for each of your neighbours in minutes. Choose Self-Serve for just the paperwork from £49, or our Guided Consent Package from £99 for full delivery, tracking, follow-ups, and consent management.

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Frequently asked questions