Building Owner Party Wall Information

Hourican Associates Ltd | 09-02-2026

I’m a Building Owner — what do I need to do under the Party Wall etc. Act 1996 before I start building? If your works affect a shared wall, boundary, or involve excavation close to a neighbouring property, you may need to follow the Party Wall process to keep your London project compliant and moving.

Does the Party Wall Act apply to your project?

In London, the Party Wall process is commonly triggered by: loft conversions, rear extensions, basement works, chimney breast removals, and deeper foundations near neighbouring buildings.

• Works to an existing party wall / party structure: cutting into, raising, underpinning, or structural alteration.
• New walls at boundaries: building at or up to the boundary (line of junction) — see boundary works guidance.
• Excavations close to neighbouring buildings: typically within 3m / 6m where depth criteria apply — see excavations advice.

If you’re unsure, we recommend a quick review of your drawings by an experienced Building Owner’s Party Wall Surveyor before notices are served.

Your obligations as the Building Owner

As the Building Owner, your responsibilities usually include:

1. Planning early — minimum notice periods are typically 1 or 2 months depending on the notice type, and more complex projects may take longer to agree an Award.
2. Identifying all relevant adjoining owners — in converted buildings (flats), there can be multiple owners to notify, and serving the correct people is essential.
3. Serving valid Party Wall Notice(s) — incorrect details can cause delays and increase cost. See Party Wall Notices in London.
4. Following the dispute procedure if there is dissent or no consent — surveyor(s) will agree an Award that sets out how works may proceed.

Speak to your neighbours first (it saves time and money)

We always advise building owners to speak to neighbours before serving formal notice. Neighbours who feel informed are often less likely to immediately appoint a separate surveyor, which can keep the process more proportionate on straightforward projects.

Serving notices correctly (and to the right people)

The Party Wall procedure starts with issuing valid notices. Without valid notice(s), the statutory process cannot properly progress. It’s also vital that notices go to all relevant owners — in some cases this may include more than one adjoining owner (for example, where the adjoining property is divided into flats).

If you want a head start, you can generate basic forms here: Create free Party Wall notices & acknowledgements — and if you’d like us to handle it professionally end-to-end, see our Party Wall Notice service.

Responses to your Party Wall Notice

When an adjoining owner receives notice, they will typically choose one of these routes:

• Consent to the works as described (in writing). Even with consent, a Schedule of Condition is usually prudent.
• Dissent and appoint their own surveyor — see Adjoining Owner Surveyor Services.
• Dissent and agree to one Agreed Surveyor acting impartially for both owners (often the most efficient route for smaller projects).

What if there’s no response within 14 days?

For notifiable party structure works and notifiable excavations, where there is no written consent within 14 days the statutory procedure treats a dispute as having arisen, and surveyor(s) are appointed to resolve matters by Award. If you’re facing difficulties, see our guide to Party Wall dispute resolution.

Costs: who pays surveyor fees?

In most residential projects, the building owner pays the reasonable costs of the Party Wall process, including the adjoining owner’s surveyor if one is appointed, because the works are for the building owner’s benefit. Adjoining owners’ surveyors commonly charge on an hourly basis and fees are usually agreed between surveyors; if surveyors cannot agree, the Third Surveyor can be called upon within the statutory process.

Basements & underpinning: expect a more detailed Award

Where works involve underpinning and basement excavation, the Party Wall Award is typically more detailed to reflect the greater risk. Depending on the project, provisions such as security for expenses and special foundation considerations may be relevant and are usually dealt with within the Award where applicable. If you’re planning below-ground works, see: Basement Party Wall Survey and Basement Schedule of Condition.

Even with consent: consider a Schedule of Condition

If your neighbour consents, it can still be prudent to have a Schedule of Condition covering areas at risk. Once works start, neighbours often notice existing cracks more closely and may assume they are new. A clear pre-works record helps prevent misunderstandings and disputes.

Frequently Asked Questions

Planning works? Send your drawings for a fast, fixed-fee proposal

If you’d like a fee proposal, please attach drawings showing the proposed works. We’ll confirm whether the Act applies, identify which notice(s) are required, and recommend the most cost-effective route (including whether an Agreed Surveyor may be appropriate).

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This page is general guidance and is not legal advice. The Party Wall etc. Act 1996 can be fact-sensitive and only a court can give an authoritative interpretation.