If you are a Building Owner planning party wall works in London, LENIO guides you through the whole Party Wall etc. Act 1996 process, from serving the right notices on your neighbours to agreeing the Party Wall Award. Every matter is handled personally by a Chartered Civil and Building Engineer (ICE and CABE).
Under the Party Wall etc. Act 1996, the term Building Owner refers to the person planning the works. If you are carrying out, or intending to carry out, works that may affect a shared wall, boundary line or neighbouring foundation, you are the Building Owner.
This does not mean you own the wall outright. In many cases, the party wall or boundary is shared between properties. As the Building Owner, you carry the duty to notify affected neighbours before notifiable works begin.
“Owner” has a specific meaning under the Act. It covers anyone who holds the freehold, holds a leasehold for a term of more than one year, or is under contract to purchase such a freehold or leasehold. The same applies to your neighbours, which is why notice sometimes has to be served on both a leaseholder and a freeholder for the same property.
The Party Wall Act is often described only as an obligation. In fact it grants a Building Owner positive rights that a neighbour cannot refuse. Provided the correct notice is served, you are entitled to carry out works such as these.
Not all building work requires a Party Wall Notice. However, many common London renovation projects do fall under the Act. As a Building Owner, your first step is to confirm whether your project is notifiable.
Works that extend close to a boundary line or involve excavation near neighbouring foundations often trigger the Act. Rear extensions are one of the most common notifiable building owner party wall projects.
Inserting steel beams into a party wall requires notice under Section 3 of the Act. Most loft conversions in terraced or semi-detached London properties involve this type of notifiable work.
Deep excavations near neighbouring structures trigger Section 6 of the Act. These projects carry the highest party wall risk and require careful survey work before construction starts.
Removing a chimney breast that is built into a party wall affects the shared structure. This requires a Party Wall Notice served on the Adjoining Owner before any works begin.
Building a new wall at or near the boundary line falls under Section 1 of the Act. This includes garden walls, new structures and works on an existing shared boundary.
Cutting into, raising, thickening or underpinning a party wall all require notice under Section 3. This applies to any work that physically alters the shared structure between properties.
Read more about party wall notices, or see the full party wall process.
Speak directly with a party wall surveyor in London. One short call is enough to confirm what applies to your project and what needs to happen next.
Call LENIO for Free AdviceSecuring planning permission confirms your local authority permits the development. However, it does not cover your obligations under the Party Wall etc. Act 1996. Both requirements apply independently, and this is true even for Permitted Development works that need no planning application at all.
Many Building Owners discover this only after construction begins. In some cases, works start before the correct Party Wall Notice has been served. This puts the Building Owner in breach of the Act, and a neighbour can apply for an injunction to stop the works until the process is followed, which usually means high legal costs and delay.
The safest approach is to confirm your party wall obligations before your contractor is booked. Starting the process early gives you enough time to follow the Act correctly without delaying your project.
Once a Party Wall Notice is served, the Adjoining Owner has 14 days to respond. Their response determines the next stage of the building owner party wall process.
If the Adjoining Owner consents in writing within 14 days, the process moves forward without the need for surveyors. Works may then proceed in accordance with the agreed terms.
In practice, consent is common on straightforward projects. However, even where a neighbour consents, a Schedule of Condition is advisable before works begin to protect both sides.
If the Adjoining Owner dissents, or if 14 days pass with no response, a dispute is treated as having arisen under the Act. This does not stop your project.
At that point, surveyors are appointed and a Party Wall Award is prepared. The Award sets out how and when works may proceed. Your project continues through the correct statutory route.
As your party wall surveyor for building owners, LENIO manages every stage of the process from initial review through to post-construction support.
We assess your drawings and proposed works against the Party Wall etc. Act 1996. This confirms whether notices are needed, which sections apply and which Adjoining Owners must be notified before works begin.
We identify every affected Adjoining Owner and prepare the correct Party Wall Notice for each. All notices are drafted to the Act’s requirements and served within the correct notice period before works start.
We follow up on every response and keep you informed throughout. If a neighbour consents, the process moves forward. If they dissent or do not reply, we manage the formal steps under the Act.
Before works begin, we carry out a Schedule of Condition survey of each affected neighbouring property. This photographic and written record protects you as the Building Owner if any damage is alleged during construction.
Where a neighbour dissents or does not respond, we prepare a legally binding Party Wall Award. This document sets out how works proceed, access arrangements and protective measures for the Adjoining Owner’s property.
Once the Award is in place, your contractor can proceed on site. We remain available throughout the build to clarify Award provisions, advise on access and ensure works stay within the agreed conditions.
The party wall obligations a Building Owner carries are set out in statute. An incorrect notice, a missed Adjoining Owner or a procedurally flawed Award can delay your project and expose you to legal challenge. The Act also confirms that a Building Owner cannot act as their own surveyor, since a surveyor is defined as any person not being a party to the matter. For this reason, specialist support from the outset is the most practical approach.
In London, building owner party wall matters arise on most renovation projects. Terraced houses, semi-detached homes and converted flats mean that party walls and shared boundaries are the norm, not the exception.
LENIO is led by a Chartered Civil Engineer and Member of the Institution of Civil Engineers (ICE), and a Chartered Building Engineer and Member of the Chartered Association of Building Engineers (CABE). A chartered surveyor leads every instruction personally, for Building Owners and Adjoining Owners across London. See our full range of party wall services, or the GOV.UK party walls guide.
LENIO provides party wall surveyor services for Building Owners across London, backed by two chartered professional memberships.
The Institution of Civil Engineers (ICE)
The Chartered Association of Building Engineers (CABE)Send us your drawings or a short description of the works. We will review them and tell you exactly what the Party Wall Act requires, with no obligation.
No. The Act grants a Building Owner positive rights, such as cutting into a party wall for a beam, raising it, underpinning it or excavating near the boundary. A neighbour cannot refuse notifiable works you are entitled to carry out.
What they can do is insist that a Party Wall Award is prepared, which sets out how and when the works proceed and how their property is protected. The Act is designed to allow reasonable works to go ahead, not to prevent them.
An owner is anyone who holds the freehold, holds a leasehold for a term of more than one year, or is under contract to purchase such a freehold or leasehold. This applies to you and to your neighbours.
It matters because notice must be served on every Adjoining Owner. In a block of flats that can mean both the leaseholders and the freeholder. Serving only the occupier is a common error that invalidates the notice.
It depends on whether the works affect a party wall, boundary line or neighbouring foundation. A loft conversion that involves inserting steel beams into a shared wall requires notice. An extension that excavates near a neighbouring structure may also trigger the Act.
The most reliable way to confirm this is to have your drawings reviewed by a party wall surveyor for building owners. We can tell you within a short call whether your project is notifiable and which notices apply.
No. The Act defines a surveyor as any person not being a party to the matter, so a Building Owner cannot act as their own surveyor or draw up their own Award.
You can serve your own notice if the works are straightforward, but the surveyor role in a dispute must be independent. This is why, once a neighbour dissents, a surveyor has to be appointed.
You must serve notice on every Adjoining Owner whose property may be affected by the proposed works. In terraced or semi-detached properties, this often means more than one neighbour, and in flats it can mean several leaseholders and the freeholder.
We identify all affected Adjoining Owners as part of our initial review. This ensures you serve notice on everyone required and avoids the risk of a missed notice later in the process.
A counter-notice is a formal notice an Adjoining Owner may serve under section 4, requiring additional works to the party wall for their own benefit or convenience, for example chasing in for services or building the wall higher. It must be served within one month of your notice.
Where the additional works benefit the Adjoining Owner, they generally meet the cost of that element. A counter-notice introduces a stage before the Award is finalised and, in most cases, does not stop your project. We manage it on your behalf.
The cost depends on the complexity of the works and how many Adjoining Owners are involved. As a general rule, the Building Owner covers the reasonable costs of the process, including any Adjoining Owner’s surveyor fees where a dispute has arisen.
LENIO provides a clear fee proposal after reviewing your project. We do not charge for initial advice. Call us to discuss your situation and we will give you an honest overview of the likely costs involved.
Yes, in some cases. An Agreed Surveyor can be appointed even after dissent, provided both the Building Owner and the Adjoining Owner agree to the single appointment. Both parties must be comfortable with one surveyor acting for both sides.
If both parties cannot agree on an Agreed Surveyor, each appoints their own, and those two surveyors then select a Third Surveyor as a statutory safeguard. We can advise on which route suits your situation.
A notice is valid for 12 months. If your neighbour consents, you should start the works within 12 months of the notice. Where there is an Award, you should usually start within 12 months of the Award.
If works do not begin within these periods, fresh notices are needed. This catches out projects delayed by planning, funding or contractor availability, so it is worth building the timing into your programme.
Not always. Internal works that do not affect a party wall, shared structure or neighbouring foundation generally do not trigger the Act. Internal decoration, floor works or non-structural alterations are unlikely to be notifiable.
However, if internal works involve cutting into, altering or strengthening a party wall, notice may be required. If you are unsure, the safest step is to have your plans reviewed before works begin.
Each Adjoining Owner responds to their own Party Wall Notice independently. If one consents and another dissents, consent stands for the first and the formal dispute process applies to the second.
In this situation, works may proceed in relation to the consenting neighbour’s boundary. For the dissenting neighbour, surveyors are appointed and a Party Wall Award is prepared before works affecting their property begin.
Whether your project is at the planning stage or your contractor is already booked, the first step is to confirm what the Party Wall etc. Act 1996 requires. LENIO provides free initial advice to Building Owners across London. There is no obligation.
