Party Wall Agreements Guide for London

If you're planning building work in London—whether a loft conversion, basement excavation, extension, or structural alterations—you'll likely need to navigate the Party Wall etc. Act 1996. This legislation protects both building owners undertaking work and adjoining owners who might be affected. Understanding the process, requirements, and costs of party wall agreements is essential for avoiding disputes, delays, and potential legal action. This comprehensive guide explains everything London property owners need to know about party walls.

What is the Party Wall Act?

The Party Wall etc. Act 1996 provides a framework for preventing and resolving disputes in relation to party walls, boundary walls, and excavations near neighbouring buildings. It applies throughout England and Wales and is particularly important in London where terraced and semi-detached properties with shared walls are common.

The Act gives building owners rights to carry out certain works while also protecting the interests of adjoining owners. Crucially, it's a civil matter—local authorities don't enforce it. If you don't comply, your neighbour can seek an injunction stopping your work and claim damages.

What is a Party Wall?

Under the Act, a party wall is:

• A wall that stands on the land of two or more owners and forms part of a building (e.g., the shared wall between terraced or semi-detached houses)
• A wall that stands on the land of two owners but doesn't form part of a building (e.g., a garden wall along a boundary with footings on both sides)
• A wall that stands entirely on one owner's land but is used by two or more owners to separate their buildings (less common)

Party structures can also include floors and other parts of buildings shared between properties (common in conversions and flats).

When Do You Need Party Wall Agreements?

The Act covers three types of work:

1. Work Directly to Party Walls (Section 2):

• Cutting into a party wall
• Removing chimney breasts on party walls
• Inserting a damp-proof course
• Raising a party wall
• Demolishing and rebuilding a party wall
• Underpinning a party wall
• Cutting into party walls to install beams (e.g., for loft conversions)
• Protecting party walls during works

2. Building New Walls on or at Boundaries (Section 1):

• Building a new wall on the boundary line
• Building a new wall entirely on your land but with foundations extending under your neighbour's land
• Building up to the boundary line (but not directly on it)

3. Excavation Near Neighbouring Buildings (Section 6):

• Excavating within 3 metres of a neighbouring building, going deeper than its foundations
• Excavating within 6 metres of a neighbouring building, cutting a line at 45 degrees down from the bottom of its foundations

This commonly applies to basement conversions, new extensions with deep foundations, and underpinning works.

Works Not Requiring Party Wall Agreements

Not all work needs party wall procedures:

• Drilling into party walls to fix shelves, cabinets, or wall hangings
• Plastering or decorating party walls
• Installing electrical sockets or switches (if not cutting deeply into the wall)
• Replacing floorboards
• Routine maintenance that doesn't affect the structure
• Work entirely on your property not affecting party walls or close to boundaries

When in doubt, consult a party wall surveyor—proceeding incorrectly can cause serious problems.

The Party Wall Process: Step-by-Step

Step 1: Prepare Detailed Plans

Before serving notices, prepare detailed drawings showing:

• Exact location and scope of proposed works
• How party walls will be affected
• Foundation depths and proximity to neighbouring properties
• Structural changes proposed

Step 2: Serve Party Wall Notices

You must serve notices to all adjoining owners (neighbours sharing party walls or affected by excavations) at least:

• Two months before starting work for Section 2 (party wall) works
• One month before starting work for Section 1 (new wall on boundary) works
• One month before starting work for Section 6 (excavation) works

Notices must be in writing and include:

• Your name and address
• Nature and details of proposed works
• Date you intend to start (at least one or two months ahead)
• Plans and drawings
• Explanation of your neighbour's rights

Serve notices to all affected owners—if a property has multiple owners (e.g., mortgaged properties), serve all of them.

Step 3: Wait for Response

Your neighbour has 14 days to respond. They can:

• Consent: Agreeing to the works in writing. You can then proceed but should still create a schedule of condition (photographic record of their property before work starts) to protect both parties
• Dissent or Not Respond: Refusing consent or not responding within 14 days triggers the dispute resolution procedure

Many neighbours don't respond simply because they're unfamiliar with the process, not because they object. Non-response is treated as dissent, triggering surveyor appointment.

Step 4: Appoint Surveyors (If Dispute Arises)

When neighbours dissent or don't respond, surveyors must be appointed. Three options exist:

• Agreed Surveyor: Both parties agree on a single surveyor to act impartially for both. Most cost-effective option (typically £1,000-£2,500 total)
• Two Surveyors: Each party appoints their own surveyor. The building owner pays both surveyors' fees (typically £2,500-£5,000+ total)
• Third Surveyor: If two surveyors can't agree, they appoint a third surveyor to make final decisions. Rare but adds significant cost

The building owner (you, undertaking the work) pays all reasonable surveyor fees, even your neighbour's surveyor if they appoint one.

Step 5: Schedule of Condition

Surveyors inspect and document the current condition of neighbouring properties through:

• Photographs of all relevant areas
• Written descriptions of existing cracks, defects, and condition
• Video surveys for comprehensive records

This provides a baseline to assess any damage caused by your works. Neighbours must provide reasonable access for this inspection.

Step 6: Party Wall Award

Surveyors prepare a Party Wall Award—a legal document detailing:

• Exact works to be undertaken
• How and when works will be carried out
• Protections for the neighbouring property
• Access rights if required
• Working hours and noise limitations
• How the property will be made good if damaged

Both parties receive copies. Once served, works can commence. The Award is binding and can be enforced through courts if necessary.

Step 7: Undertake Works

Carry out works in accordance with the Award. If you deviate from what's agreed, you may be in breach, potentially facing injunctions or damages claims.

Step 8: Post-Work Inspection

After completion, surveyors may inspect neighbouring properties again to identify any damage caused. If damage occurred, you're responsible for making good or compensating your neighbour.

Costs of Party Wall Agreements

The building owner pays all party wall costs, including neighbours' surveyor fees if they appoint one:

Agreed Surveyor (one surveyor for both parties): £1,000-£2,500

• Simple extension or loft conversion with straightforward party wall issues
• Cooperative neighbours
• Standard terrace or semi-detached property

Two Surveyors (each party appoints their own): £2,500-£5,000

• More complex works
• Multiple affected neighbours
• Basement conversions or significant excavations
• Properties in premium areas where surveyors' fees are higher

Complex Projects: £5,000-£10,000+

• Large developments affecting multiple neighbours
• Significant basement excavations or structural work
• Disputes requiring extensive negotiations
• Third surveyor appointment

Costs typically cover:

• Reviewing plans and preparing Awards
• Site visits and inspections
• Schedules of condition (photography and documentation)
• Negotiations between parties
• Serving Awards
• Post-work inspections if required

Common Mistakes and How to Avoid Them

Starting Work Without Serving Notices: The most serious mistake. Neighbours can seek injunctions stopping your work and claim damages. Always serve proper notices with adequate notice periods.

Serving Notices Too Late: Remember the two-month (Section 2) or one-month (Sections 1 and 6) notice periods. Starting work earlier than stated in your notice is a breach.

Incomplete or Vague Notices: Notices must clearly detail proposed works. Vague descriptions can be challenged. Include proper drawings and specifications.

Not Serving All Affected Owners: If excavating, you must serve notices to all properties within the relevant distance (3m or 6m). Missing someone can cause problems.

Assuming Consent Means No Need for Precautions: Even with consent, create schedules of condition to protect yourself against unfounded damage claims.

Ignoring the Award Terms: Once an Award is agreed, you must follow it. Deviating from agreed working hours, methods, or scope breaches the Award.

DIY Approach for Complex Works: While property owners can technically handle party wall matters themselves, professional surveyors are strongly recommended, particularly for substantial projects. Mistakes can be very costly.

Your Rights as a Building Owner

The Act gives you important rights:

• Right to undertake necessary works to your property
• Right of access to neighbouring property if reasonably required (with notice)
• Protection from unreasonable refusal of necessary works
• Right to appoint a surveyor to protect your interests

However, these rights come with responsibilities—you must follow proper procedures, compensate for any damage, and work reasonably to minimise disturbance.

Your Neighbour's Rights

Understanding your neighbour's rights helps ensure smooth processes:

• Right to be notified before work starts
• Right to appoint their own surveyor (at your cost)
• Right to refuse consent (triggering surveyor appointment)
• Protection from damage—you must make good any damage caused
• Right to compensation if their property is affected
• Right to reasonable working hours and methods

Maintaining good relationships with neighbours makes the process much smoother, even when formal procedures are required.

Party Walls in Different Property Types

Terraced Houses: Typically have party walls on both sides. Most extensions, lofts, or basements require party wall notices to both neighbours.

Semi-Detached Houses: One party wall, usually requiring notice to one neighbour for most works.

Detached Houses: No party walls, but excavation works within 3-6 metres of neighbouring properties still trigger Section 6 requirements.

Flats: Can be complex with party walls, party floors, and multiple owners in the same building. May need notices to multiple neighbours above, below, and beside.

Resolving Disputes

If disputes arise despite the Award:

• Surveyors should attempt to mediate
• Third surveyor can make binding decisions
• As a last resort, either party can appeal to county court (within 14 days of Award)
• Court appeals are expensive and time-consuming—avoided where possible

Most disputes resolve through professional surveyor involvement without court action.