Party Wall Advice for House Extensions
Building an extension close to a neighbouring property may require formal Party Wall Notices before work begins. Understanding the process early can help avoid unnecessary delays and disputes.
Planning an extension often involves more than obtaining planning permission and preparing Building Regulations drawings.
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Depending on the position of the proposed work, the Party Wall etc. Act 1996 may also apply.
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Many homeowners associate the Act with major structural work to a shared wall. However, it can also apply to a relatively straightforward rear or side extension where new foundations are excavated close to a neighbouring building.
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The best approach is to check the position early and deal with any necessary notices before construction begins.
The Party Wall Act Can Apply Even When You Build on Your Own Land
A rear or side extension may require Party Wall Notices because the new foundations are close to a neighbouring building.
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The Act can apply even where the extension itself is entirely within your own property boundary.
What Is the Party Wall etc. Act 1996?
The Party Wall etc. Act 1996 provides a framework for preventing and resolving disputes between property owners where certain types of building work may affect a neighbouring property.
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The Act does not prevent homeowners from extending or improving their property.
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Its purpose is to make sure that adjoining owners are notified properly and that the relevant procedures are followed before notifiable work begins.
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The process can also provide a clearer record of the work being undertaken and the condition of neighbouring property before construction starts.
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Is a Party Wall Agreement the Same as Planning Permission?
No.
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Party wall matters are separate from planning permission and Building Regulations approval.
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Receiving planning permission does not remove the need to comply with the Party Wall etc. Act where it applies.
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Equally, obtaining Building Regulations approval or structural calculations does not replace the need to serve the appropriate Party Wall Notices.
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An extension project may therefore involve several separate steps:
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planning permission or confirmation that the work falls within permitted development rights;
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Building Regulations drawings and approval;
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structural calculations;
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Party Wall Notices where required; and
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a Party Wall Award where the adjoining owner does not consent to the notified work.
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These matters should be considered together before the builder starts work.
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When Does the Party Wall Act Apply?
The Act can apply in three main situations.
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1. Building a New Wall on or Close to the Boundary
A notice may be required where a homeowner wants to build a new wall at or astride the boundary line between two properties.
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This can be relevant to rear extensions, side extensions and wraparound extensions.
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Where a wall is built entirely on the homeowner’s own land but close to the boundary, the position still needs to be considered carefully.
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A homeowner cannot normally build a new wall astride the boundary without the adjoining owner’s written consent.
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2. Carrying Out Work to an Existing Party Wall or Party Structure
A Party Wall Notice may be required where work affects an existing shared wall or structure.
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Common examples include:
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cutting into a party wall to support a steel beam;
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inserting padstones or structural supports;
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raising the height of a party wall;
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rebuilding or repairing a party wall;
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underpinning a party wall;
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removing a chimney breast from a shared wall;
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cutting off projections to allow a new wall to be built; and
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carrying out structural alterations affecting a shared wall.
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This type of work can arise during an extension, loft conversion, basement project or internal reconfiguration.
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3. Excavating Close to a Neighbouring Building
This is one of the most common reasons an extension project falls within the Act.
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A notice may be required where the proposed foundations are excavated within 3 metres of a neighbouring building or structure and extend deeper than the bottom of the neighbour’s foundations.
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A notice can also be required for deeper excavations within 6 metres in certain circumstances.
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This means that the Act may apply even where the new extension walls and foundations are entirely within the homeowner’s own land.
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For many terraced and semi-detached houses, extension foundations are likely to be relatively close to a neighbouring property. The excavation rules should therefore be checked as part of the design process.
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What Is a Party Wall?
A party wall is commonly understood as the shared wall between two terraced or semi-detached houses.
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However, the definition can be wider than this.
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A party wall may include:
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a wall standing astride the boundary between two properties;
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a wall forming part of one building and separating it from another;
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a wall built wholly on one owner’s land but used by both owners to separate their buildings;
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a shared floor or other structure separating flats; and
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certain masonry walls standing astride the boundary.
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A timber fence, hedge or lightweight garden screen is not normally treated as a party wall.
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The legal position depends on the construction and location of the wall rather than the way it is described informally.
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Does Every Extension Need a Party Wall Notice?
No.
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An extension does not automatically require a Party Wall Notice.
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The answer depends on:
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the position of the boundaries;
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the distance between the proposed excavation and neighbouring buildings;
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the likely depth of the new foundations;
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the depth of the neighbour’s foundations;
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whether a new wall is being built at or astride the boundary;
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whether the design affects an existing party wall; and
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whether steel beams or other structural elements will be inserted into a shared wall.
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A detached house with generous space around it may not trigger the Act.
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A terraced or semi-detached house with close neighbours is more likely to require consideration.
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Each project should be reviewed on its own facts.
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Do You Need a Party Wall Notice for a Rear Extension?
Often, but not always.
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The foundations for a rear extension may be within 3 metres of a neighbouring house or rear addition.
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Where the proposed excavation is deeper than the bottom of the neighbouring foundations, the work may fall within the Act.
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A notice may also be needed where the extension involves:
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building a wall at or astride the boundary;
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connecting to an existing party wall;
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cutting into a party wall;
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installing structural support; or
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altering a shared structure.
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The position should be checked once the extension layout and foundation assumptions are known.
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Do You Need a Party Wall Notice for a Side-Return Extension?
A side-return extension frequently requires careful Party Wall consideration.
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Victorian and Edwardian terraced houses often have narrow side-return areas close to the boundary and the neighbouring rear addition.
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The project may involve:
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new foundations close to the neighbour’s building;
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construction close to the boundary;
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alterations to an existing shared wall;
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steel beams supporting a wider internal opening; and
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changes to the original rear wall of the house.
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A wraparound extension can raise similar issues because it combines rear and side-return construction.
What Is a Party Wall Notice?
A Party Wall Notice is a formal written notification served on the adjoining owner before notifiable work begins.
The type of notice depends on the work being proposed.
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The notice should describe the relevant work clearly and include the required information.
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For excavation work, drawings should show the location and depth of the proposed foundations or excavations.
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The homeowner carrying out the work is usually referred to as the Building Owner.
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The neighbouring owner is usually referred to as the Adjoining Owner.
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There may be more than one adjoining owner. For example, a neighbouring property may have both a freeholder and a long leaseholder who need to be notified.
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How Much Notice Should Be Given?
The notice period depends on the type of work.
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As a general guide:
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work to an existing party wall or party structure normally requires at least 2 months’ notice; and
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a new wall at the boundary or excavation near a neighbouring building normally requires at least 1 month’s notice.
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A notice should not be served too early because it will not remain valid indefinitely.
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It is sensible to review the likely programme before starting the process.
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What Can the Neighbour Do After Receiving a Notice?
An adjoining owner can respond in several ways.
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Consent to the Work
The neighbour may provide written consent.
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This is often the simplest outcome.
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Consent does not remove the Building Owner’s responsibility to carry out the work properly and make good any damage caused by the notified work.
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It is often sensible to record the condition of the neighbouring property before construction begins, even where the neighbour is cooperative.
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Dissent and Appoint a Surveyor
The adjoining owner may dissent and appoint a party wall surveyor.
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The Building Owner must then appoint a surveyor as well.
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The two owners may sometimes agree to use the same impartial surveyor, known as an agreed surveyor.
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Alternatively, each owner can appoint a separate surveyor.
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Do Not Respond
Where the adjoining owner does not respond to certain notices within the relevant period, a dispute may be deemed to have arisen.
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The Party Wall process can then move forward through the appointment of surveyors.
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Ignoring the notice does not necessarily prevent the work from progressing, but it can make the process more formal.
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What Is a Schedule of Condition?
A Schedule of Condition is a written and photographic record of the adjoining property before work begins.
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It may record matters such as:
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existing cracks;
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decorative condition;
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plasterwork;
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walls and ceilings;
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external brickwork;
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paving;
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boundary walls; and
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other visible defects.
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The Schedule of Condition can help protect both owners.
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If damage is alleged after work begins, there is a clearer record of the property’s condition before construction started.
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It can therefore reduce arguments and make genuine damage easier to identify.
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What Is a Party Wall Award?
Where the adjoining owner dissents or does not respond, the appointed surveyor or surveyors may prepare a Party Wall Award.
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The Award is a legal document setting out the basis on which the notifiable work can proceed.
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Depending on the project, it may address:
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the work being carried out;
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the drawings and structural details;
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the construction method;
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access arrangements where relevant;
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working hours;
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protective measures;
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the Schedule of Condition;
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the making good of damage; and
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the surveyors’ fees.
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The Award does not replace the builder’s construction contract or the Building Regulations drawings.
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It deals specifically with the notifiable work and the rights and responsibilities arising under the Act.
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Who Pays the Party Wall Surveyor’s Fees?
In most extension projects, the Building Owner carrying out the work will usually be responsible for the reasonable costs arising from the Party Wall process.
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This may include the reasonable fees of the adjoining owner’s surveyor where a separate appointment is made.
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The cost can vary depending on:
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the complexity of the project;
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the number of adjoining owners;
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whether one agreed surveyor or separate surveyors are appointed;
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the quality of the drawings and structural information;
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whether additional visits are needed; and
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whether disagreements arise.
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Dealing with the matter early and providing clear information can help keep the process proportionate.
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Can the Neighbour Stop the Extension?
A neighbour cannot normally use the Party Wall Act simply to prevent lawful work from taking place.
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However, the adjoining owner can influence how and when notifiable work is carried out through the statutory process.
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Starting notifiable work without serving the appropriate notices can create avoidable problems.
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The adjoining owner may seek an injunction or other legal remedy if the work proceeds without the correct procedure being followed.
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The safest approach is to identify the requirements and deal with them properly before construction begins.
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What Happens If You Start Work Without Serving Notice?
Ignoring the Party Wall Act can expose the homeowner to unnecessary risk.
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Possible consequences include:
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disputes with neighbours;
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delays to construction;
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additional professional fees;
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legal costs;
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an application for an injunction;
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difficulty resolving allegations of damage; and
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strained relationships with adjoining owners.
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A retrospective attempt to resolve the position is usually less satisfactory than serving the appropriate notices at the correct time.
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Speak to Your Neighbours Early
A formal notice may be required, but an early conversation can still be helpful.
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Explaining the project before documents arrive unexpectedly can reduce concern and make the process easier for everyone.
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It is useful to explain:
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what work is proposed;
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when construction is likely to begin;
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how long the project may take;
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whether access may be needed;
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how the site will be managed; and
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who the neighbour can contact if they have questions.
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A professional process and a courteous approach can go a long way.
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Party Wall Advice Should Be Considered Early
Party wall matters should not be left until the builder is ready to start excavating foundations.
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The correct time to review the position is usually once the proposed layout is reasonably clear and before construction dates are agreed.
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Early advice can help identify:
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which adjoining owners need to be notified;
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which types of notice may be required;
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the likely timescale;
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the drawings and structural details needed; and
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whether the construction programme should allow for a Party Wall Award.
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This can reduce delays and give the homeowner a clearer route into the building stage.
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Tell Us About Your Extension
Planning a rear extension, side-return extension, wraparound extension, double-storey extension or a larger renovation project?
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Tell us a little about your property and what you are hoping to achieve. Where appropriate, we can help you identify the professional support you may need, from architectural design and planning advice through to Building Regulations drawings, structural engineering, Party Wall advice and suitable extension contractors.