It’s easy to assume that just because you own your property, you can build wherever and however you want. But when your project creeps close to a neighbour’s space—or, worse, straddles the boundary—you’re entering legal territory. That’s where the Party Wall Act comes in.
Section 1 of the Party Wall etc. Act 1996 applies to new building work at the boundary line between two properties. The law came into force on 1 July 1997, and it’s valid across England and Wales. (Scotland and Northern Ireland? Sorry, you’re playing by different rules.)
Whether you're planning to build a wall, fence, or any other permanent structure that touches or crosses a boundary, the Act requires you to notify your neighbour and—depending on their response—either move forward with shared costs or handle it yourself. Now, you may be wondering, How Much Notice Do You Need to Give? Well, the law sets out a clear time frame for notifying your neighbour before starting the work.
Here’s the simple definition: a party wall is a wall shared by two properties. It might sit directly on the boundary or fully on one person’s land but still serve both buildings. That includes the garden fence you both pretend not to care about—until one of you starts knocking it down at 7 AM. Want more details? What Is Section 1 of the Party Wall Act? It’s the section that kicks off the whole process, setting the rules for party walls and how to handle those inevitable neighbourly discussions.
Section 1 covers new walls and fences built on or at the boundary line. It also applies if the wall is intended to serve both properties. Key situations include:
Building a new wall on the boundary line (aka “line of junction”)
Excavating within 3 to 6 metres of an adjoining structure
Constructing a building astride or right up to the boundary
If you're the building owner, you must serve a written notice to your neighbour at least one month in advance before construction begins. The notice should clearly state your intentions and include detailed plans if possible.
One of two things can happen:
Your neighbour agrees in writing—great! Work can begin as planned.
They don’t respond or object—you enter what’s known as a dispute.
In the case of a dispute, Section 10 of the Act kicks in. That means both parties must appoint surveyors (or agree on one) to resolve the issue fairly and legally.
Ah yes, the money question. The cost is usually shared in proportion to how each party will benefit. If you’re building a wall to serve both properties, expect to split the bill. If your neighbour consents but won’t benefit from the wall? That’s your expense to carry.
If your building work damages your neighbour’s property cracked walls, shifting fences, or worseyou’re on the hook. Compensation is required under the Act, and it’s better to resolve it quickly than argue over it for years at the garden gate.
If the neighbour doesn’t give consent within 14 days, you can still proceed but only by placing the wall entirely on your own land and covering the full cost. No shared benefit, no shared bill.