When Do I Need a Party Wall Agreement?

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When Do I Need a Party Wall Agreement?

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Planning building works in London? Certain projects that affect a shared wall, boundary, or nearby foundations require a Party Wall Agreement (also called a Party Wall Award) under the Party Wall etc. Act 1996. This guide explains when you legally need one, how the process works, and why using a chartered party wall surveyor in London helps avoid costly delays and disputes.

What Is a Party Wall Agreement?

A Party Wall Agreement is a legally binding document prepared by an appointed surveyor that regulates how works affecting a shared or adjoining structure are carried out. It typically sets out:

  • The exact works permitted and methods of construction.
  • Working hours and access arrangements.
  • A Schedule of Condition of the adjoining owner’s property pre-works.
  • Procedures for resolving disputes and making good any damage.
Illustration of London terraced houses with a chartered party wall surveyor discussing a Party Wall Agreement under the Party Wall etc. Act 1996

When Do You Need to Serve a Party Wall Notice?

Before starting any notifiable works, you must serve the correct notice(s):

1) Works to a Party Wall or Party Structure — Section 2 Notice

  • Cutting into a party wall (e.g. inserting steel beams for a loft conversion).
  • Removing or enclosing a chimney breast attached to a shared wall.
  • Raising, thickening, underpinning, or demolishing a party wall.
  • Inserting flashing or damp-proof courses.

2) Excavation Near Neighbouring Foundations — Section 6 Notice

  • Excavating within 3 metres of a neighbouring structure to a lower level than its foundations.
  • Excavating within 6 metres where piling or deep foundations trigger the 45° line criteria.

Common examples: rear/side extensions with deep foundations, underpinning, and basement construction.

3) New Walls on or at the Boundary — Section 1 Notice

  • Building a new wall on the line of junction (boundary).
  • Building a new wall astride the boundary (requires neighbour’s written consent).
  • Constructing a new party fence wall (e.g. a garden wall built on the boundary).

Do You Always Need a Full Party Wall Agreement?

If you serve a valid notice and your neighbour consents in writing within 14 days, an Award may not be required. If they dissent or do not reply within 14 days, a dispute is deemed to have arisen under the Act and surveyor(s) must be appointed to agree a formal Award.

Why Use a Chartered Party Wall Surveyor?

  • Correct, legally valid notices under the Act.
  • Independent, impartial administration of the process.
  • Robust Schedule of Condition to protect all parties.
  • Clear procedures for access, method statements, and damage resolution.

Hourican Associates are regulated by RICS, and members of the FPWS, CIOB, and MCABE.

Typical London Projects That Trigger the Act

  • Loft conversions involving steel beams.
  • Rear and side extensions.
  • Basement excavations and underpinning.
  • Chimney breast removals.
  • New boundary or party fence walls.

Transparent Fixed Fees

Party Wall Notice Service

£150 + VAT

Per adjoining owner

Schedule of Condition Survey

£385–£585 + VAT

Basement surveys priced separately

Full Party Wall Award

£1,100–£1,500 + VAT

Serving notice, survey & agreeing the Award

London Areas We Cover

We work across all London boroughs including:

Chelsea, Kensington, Fulham, Chiswick, Clapham, Richmond, Westminster & more.

Frequently Asked Questions

If your works fall under Sections 1, 2, or 6 of the Party Wall etc. Act 1996, serving notice is a legal requirement. Failing to do so can result in injunctions, delays, and potential costs.

Yes, but notices must be drafted correctly and reference the correct section(s) of the Act. Many owners appoint a surveyor to ensure validity and avoid delays caused by defective notices.

If there is no response within 14 days, it is deemed a dissent. Each owner must appoint a surveyor (or agree to one Agreed Surveyor) who will produce a Party Wall Award.

Allow 4–8 weeks from serving notice to agreeing the Award, depending on complexity, access for inspections, and neighbour cooperation. Serve notice well before your intended start date.

Usually the building owner (carrying out the works) pays all reasonable surveyor costs, including the adjoining owner’s surveyor, where appointed.

No. Starting notifiable works without valid notice and, where required, an Award can lead to injunctions, delays, and additional costs. Wait until the process is complete.

The Schedule of Condition provides an objective record before works begin. Any damage caused by the works must be made good at the building owner’s expense or compensated as set out in the Award.

A neighbour may dissent, which triggers the surveyor process, but cannot prevent lawful works. The Award regulates how and when the works proceed to protect both parties.

Section 1 (new walls on/at boundary): at least 1 month.
Section 2 (works to party structures) and Section 6 (excavations): at least 2 months. Serve notices early to accommodate surveys and Award preparation.

Provide clear descriptions of the works, drawings showing the proposals and sections where relevant, your intended start date, and your contact details. Your surveyor can prepare compliant notices for you.
Richard Hourican. Specialist Party Wall surveyor, London

Richard Hourican, Company Director

BSc (Hons). HND Build. MCIOB. C.Build E MCABE. ARICS. MFPWS. MPTS

As a specialist Party Wall surveyor, Richard Hourican will protect your interests during building works.

Are you planning a building project – perhaps an extension, loft conversion or basement – that is on or adjacent to your property’s boundary line? Or has a ‘Party Wall’ notice dropped on the doormat informing you of a neighbour’s impending works?

It’s essential to understand all the implications of building plans. If you don’t, it could cost thousands. Our job is to ensure everything is done correctly – and that it doesn’t!

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