Party Wall Temporary Works

When people think about the Party Wall etc. Act 1996, they usually think about notices, Party Wall Awards and surveyors.

What is discussed far less often is what actually happens during construction.

A rear extension may require an existing wall to be temporarily exposed. A basement excavation may require shoring and temporary support. A structural opening may need steelwork and temporary propping before the permanent structure is installed. A loft conversion may leave parts of a party wall exposed to the weather while the new roof is being formed.

These temporary stages can sometimes carry more risk than the finished building itself.

For that reason, temporary works can become an important part of the Party Wall process.

This guide explains what temporary works are, why they matter, what protections the Party Wall etc. Act 1996 provides, and what building owners and adjoining owners should expect before construction begins.

What are temporary works?

Temporary works are structures, measures or arrangements needed during construction but which do not normally form part of the completed building.

Examples can include:

• temporary propping;
• shoring;
• excavation supports;
• temporary weatherproofing;
• hoarding;
• protective fans;
• temporary roof coverings;
• temporary retaining works;
• trench support;
• temporary structural bracing;
• temporary access platforms; and
• protection to an adjoining building while permanent works are being completed.

They are often removed once the permanent structure has been completed.

Temporary works can therefore be easy to overlook when architectural drawings are prepared.

However, from a Party Wall perspective, the period between removing the existing structure and completing the new one can be extremely important.

Why temporary works matter in Party Wall projects

Consider a simple example.

A homeowner wants to create a large opening at the rear of a terraced house.

The finished design may include a substantial steel beam supporting the wall above.

Once completed, the arrangement may be perfectly stable.

But before the steel beam is installed, part of the existing wall may need to be removed.

That means the structure must be supported temporarily while the permanent beam is positioned.

The risk exists during the construction sequence, not necessarily in the finished design.

The same principle applies to excavation.

A completed reinforced foundation may be extremely strong.

However, the period when soil has been removed and the new foundation has not yet been completed can be the stage at which neighbouring structures are most vulnerable.

This is why Party Wall surveyors frequently need to understand not only what is being built, but also how it will be built.

Does the Party Wall Act specifically deal with temporary protection?

Yes.

Section 7 of the Party Wall etc. Act 1996 contains important protections for adjoining owners.

Where exercising rights under the Act exposes part of the adjoining land or building, the building owner must, at their own expense, provide and maintain appropriate temporary protection where necessary.

The legislation specifically refers to measures including hoarding, shoring, fans and temporary construction for the protection of adjoining land or buildings and the security of adjoining occupiers.

This is an important part of the legislation.

The Act does not simply provide a building owner with rights to undertake certain works. Those rights come with responsibilities.

Temporary works and unnecessary inconvenience

Section 7 also provides that rights under the Act should not be exercised in a way or at a time that causes unnecessary inconvenience to an adjoining owner or occupier.

That does not mean construction must be completely inconvenience-free.

Building work inevitably creates some disruption.

The important distinction is between unavoidable inconvenience associated with reasonably carrying out the work and inconvenience that could reasonably have been prevented.

Temporary works can therefore help reduce disruption as well as physical risk.

For example:

• secure hoarding may keep a neighbouring garden usable;
• temporary waterproofing may prevent rain penetration;
• properly designed shoring may reduce the risk of movement;
• protection to paving may prevent avoidable damage; and
• sensible sequencing may shorten the period during which neighbouring property is exposed.

What can a Party Wall Award say about temporary works?

Where a dispute has arisen and surveyors are appointed under Section 10, the surveyor or surveyors can determine matters connected with work to which the Act relates.

Government guidance explains that a Party Wall Award can specify how and when works are undertaken and can require additional measures necessary to protect neighbouring property.

In practice, an Award relating to more substantial works may therefore include provisions dealing with matters such as:

• temporary support;
• excavation sequencing;
• trench lengths;
• temporary weather protection;
• working methods;
• protection of exposed walls;
• temporary access;
• structural engineering information;
• temporary works design;
• making good; and
• restrictions on changing the approved construction method without review.

For a broader explanation of Awards, see our guide to Party Wall Awards.

Temporary propping

Temporary propping is one of the most common temporary works used during structural alteration.

Props support part of a building while the permanent structure is being changed.

Examples include supporting:

• masonry above a new opening;
• floors while a wall is removed;
• roofs during loft works;
• party walls during structural alteration; or
• sections of a building during installation of new beams.

Why propping needs proper consideration

Removing a structural wall before appropriate support is installed can allow loads to redistribute unexpectedly.

This can result in:

• cracking;
• movement;
• deformation;
• local structural failure; or
• damage to finishes in neighbouring properties.

The temporary support should therefore be appropriate for the loads involved and the sequence of construction.

For significant structural works, temporary propping may need to be designed or reviewed by a structural engineer rather than left entirely to site judgement.

Acrow props are not automatically a complete temporary works design

Acrow props are commonly used during domestic construction.

They can be extremely useful, but the fact that a contractor intends to use Acrow props does not by itself demonstrate that the temporary support arrangement is adequate.

Questions may include:

• What exactly are the props supporting?
• How is the load transferred into the prop?
• What supports the bottom of the prop?
• How many props are required?
• How are lateral loads controlled?
• How long will the support remain in position?
• Is the existing floor capable of carrying the temporary concentrated load?

The answer depends on the structure.

A responsible Party Wall process should avoid pretending that every temporary support arrangement requires elaborate engineering, while recognising when a project is sufficiently complex that proper design information is appropriate.

Shoring explained

Shoring is temporary support used to stabilise a structure, excavation or surrounding ground.

It is particularly relevant to:

• deep excavation;
• basement works;
• underpinning;
• retaining walls;
• unstable masonry; and
• demolition.

Shoring arrangements can take many different forms depending on the project.

The important Party Wall principle is that an adjoining building should not be unnecessarily exposed to instability while the building owner’s works are taking place.

Excavation support

Excavation is one area where temporary works become especially important.

Section 6 of the Party Wall Act deals with certain excavations close to neighbouring buildings.

You can read our detailed Section 6 Party Wall Notice guide for the statutory distance and depth tests.

But satisfying the notice procedure is only the beginning.

Once excavation starts, contractors need to consider the stability of:

• excavation faces;
• neighbouring foundations;
• surrounding soil;
• temporary trenches;
• boundary structures; and
• any structures close to the excavation.

Why open trenches can create risk

Soil provides lateral support.

Removing it changes the conditions around nearby structures.

This does not mean every extension trench is dangerous.

But excavation depth, ground conditions, neighbouring foundations, water and construction sequence can all affect risk.

For this reason, Party Wall Awards sometimes regulate how long or how extensively excavation can remain open before new foundations are formed.

Hit-and-miss excavation

One technique sometimes used where excavation takes place particularly close to an existing structure is sectional or “hit-and-miss” excavation.

Instead of excavating the entire length at once, work is carried out in alternate sections.

Once those sections have been completed and stabilised, the intervening sections are excavated.

Simple Survey has a dedicated guide explaining Party Wall hit-and-miss foundation bays.

The principle is straightforward: reduce the length of unsupported ground at any one time.

Whether this is appropriate depends on the engineering and ground conditions of the particular project.

Temporary works during underpinning

Underpinning deserves particular attention because the construction sequence is fundamental to the safety of the work.

The finished underpinning may eventually strengthen the structure.

But during construction, the contractor is excavating beneath or adjacent to foundations that are already supporting a building.

Work is therefore commonly undertaken in carefully controlled stages.

Temporary considerations may include:

• excavation sequence;
• maximum open pin length;
• temporary support;
• timing of concrete placement;
• curing periods;
• structural connections; and
• the order in which subsequent bays are opened.

For more detail, read our dedicated guide to underpinning under the Party Wall Act.

Temporary weatherproofing

Temporary weather protection is often overlooked because it is not part of the final architectural design.

Yet it can be extremely important.

Section 2 of the Party Wall Act expressly recognises situations where a party wall or structure is exposed and requires adequate weathering.

When can a party wall become exposed?

This can happen when:

• an existing extension is demolished;
• a neighbouring building is reduced in height;
• a roof is removed;
• an attached structure is taken down;
• a new extension is constructed in stages; or
• one side of a previously enclosed party wall becomes exposed externally.

A wall designed to sit internally between two buildings may not have been built to resist prolonged exposure to rain.

Temporary protection can therefore be essential.

What might temporary weatherproofing include?

Depending on the situation:

• temporary sheeting;
• waterproof membranes;
• temporary flashings;
• coverings to exposed masonry;
• protection to roof junctions;
• temporary caps to wall tops; or
• temporary roof arrangements.

The objective is not cosmetic perfection.

The objective is to protect the building while the permanent weathering detail is completed.

Permanent flashing versus temporary weather protection

These are different issues.

Temporary weatherproofing protects the structure during construction.

Permanent flashing forms part of the finished building.

The Act includes rights relating to cutting into an adjoining owner’s wall in certain circumstances to insert flashing or other weatherproofing where a new wall is erected against it.

Simple Survey has a separate guide covering Party Wall waterproofing and flashing.

Temporary roof protection

Roof alterations can leave a property particularly vulnerable.

Rain entering an open roof can cause significant damage very quickly.

Projects involving loft conversions, mansards and major roof alterations should therefore consider how the building will remain protected between demolition and completion of the new roof.

Depending on the works, protection could involve:

• temporary roof sheeting;
• tarpaulins;
• temporary framed coverings;
• staged removal of existing roofing; or
• sequencing the works to minimise exposure.

Again, the solution should be proportionate to the project.

Hoarding and site separation

Temporary hoarding can perform several functions.

It can:

• separate construction activity from neighbouring land;
• improve site security;
• protect adjoining occupiers;
• control debris;
• define an access route; and
• prevent accidental encroachment.

Section 7 specifically refers to hoarding where part of adjoining land or a building is laid open through work being carried out under the Act.

Protective fans

Protective fans are temporary platforms or structures designed to catch falling debris.

They are more common on larger or higher-rise projects but are specifically recognised within Section 7 of the Act.

For small domestic projects they may rarely be necessary.

Their inclusion in the legislation nevertheless demonstrates the broader principle: if works expose neighbouring land or occupiers to a foreseeable construction risk, proportionate temporary protection should be considered.

Temporary works and Party Wall access

Temporary works sometimes need to be installed from the adjoining owner’s land.

For example, scaffold or temporary protection may be needed on the neighbour’s side to safely carry out notifiable work.

Section 8 of the Party Wall Act contains rights of entry where access is necessary for work carried out in pursuance of the Act.

The legislation requires notice of entry, ordinarily 14 days unless there is an emergency.

However, Section 8 should not be treated as a general construction access licence.

What Section 8 does not automatically cover

A building owner should not assume Party Wall rights allow them to use a neighbour’s property simply because doing so would make the project easier.

Examples requiring separate consideration can include:

• general storage of materials;
• skips;
• welfare facilities;
• contractor parking;
• crane oversailing;
• scaffold used purely for non-notifiable works; or
• general site logistics unrelated to works under the Act.

For a detailed explanation, read our guide to Party Wall access rights and our comparison of oversailing licences and Party Wall access.

Temporary works drawings

Not every small domestic project requires a dedicated temporary works drawing package.

But as the structural complexity increases, surveyors may reasonably want more information.

This could include:

• temporary propping plans;
• excavation sequences;
• underpinning sequences;
• shoring details;
• method statements;
• structural calculations;
• temporary roof details; or
• construction-stage sections.

The objective should be proportionality.

A straightforward loft beam installation should not necessarily be treated like a basement beneath a five-storey building.

Equally, major excavation should not be managed using vague statements such as “contractor to support as required”.

What drawings are legally required with Party Wall Notices?

For Section 6 excavation notices, the Act requires plans and sections showing the site and depth of the proposed excavation.

Simple Survey explains the requirements in detail in What Drawings Are Needed with a Party Wall Notice?.

Temporary works information may then be requested where reasonably necessary to resolve the dispute and understand how the works are to be carried out.

Who designs temporary works?

Responsibility depends on the project and contractual arrangements.

Temporary works might be designed by:

• the structural engineer;
• a specialist temporary works engineer;
• the contractor;
• a specialist subcontractor; or
• another competent designer.

Party Wall surveyors do not ordinarily replace the engineer responsible for designing the works.

Their role is different.

They may review whether sufficient information has been provided to understand the impact on adjoining property and may seek specialist engineering input where reasonably necessary.

The role of an advising engineer

For complicated projects, an adjoining owner’s Party Wall surveyor may seek advice from an independent structural engineer.

This is particularly common with:

• basements;
• underpinning;
• deep excavation;
• unusual structures;
• substantial temporary works; or
• challenging ground conditions.

The engineer’s role is generally to advise the Party Wall surveyor on structural issues relevant to adjoining property.

It should not become an excuse to redesign the entire development unnecessarily.

The level of review should remain proportionate to the risk.

Temporary works and changes during construction

One of the most common practical problems occurs when a contractor changes the construction method after the Party Wall documentation has been completed.

Perhaps:

• strip foundations become piles;
• the excavation becomes deeper;
• additional temporary propping is needed;
• the contractor changes the underpinning sequence;
• steelwork moves;
• a different structural opening is formed; or
• temporary access requirements change.

Section 7 requires works carried out under the Act to follow the plans, sections and particulars agreed between the owners or determined through the Section 10 process, with changes dealt with appropriately rather than simply made unilaterally.

Tell your Party Wall surveyor before changing notifiable works

A sensible rule is:

If the change affects the works described in the Party Wall Notice or Award, tell the surveyor before carrying it out.

Not every minor contractor adjustment requires a new Award.

But a material change in structural design, excavation depth, temporary support or methodology may require review.

Our guide Works Started But Now You Need a New Party Wall Notice explains this issue further.

Temporary works and Security for Expenses

Major temporary works can sometimes increase the relevance of Security for Expenses under Section 12.

The principle is particularly important where abandoning the project halfway through could leave the adjoining property exposed or unstable.

For example, imagine a basement project where excavation has begun and substantial temporary support is in place.

If the building owner suddenly runs out of money and the contractor leaves site, the adjoining owner may face a serious problem.

Government guidance specifically recognises Security for Expenses as protection where there is a risk of works being left unfinished at an inconvenient stage.

The amount and form of security will depend on the circumstances.

It is generally more relevant to substantial or intrusive projects than straightforward domestic alterations.

What should Building Owners do?

If you are carrying out Party Wall works involving meaningful structural alteration, temporary works should be considered before construction begins.

A good approach is to:

1. Obtain proper structural information.
   Make sure the permanent design is sufficiently developed.
2. Ask how the building will be supported during construction.
   Do not focus solely on the finished structure.
3. Identify any temporary exposure of neighbouring property.
   Consider weather, security and structural support.
4. Provide information to your Party Wall surveyor early.
   Construction methodology is easier to resolve before the contractor is mobilised.
5. Coordinate the contractor and engineer.
   Both need to understand any requirements contained within the Party Wall Award.
6. Do not change substantial details without review.
   Send revised drawings or methodologies to the surveyor before implementing them.
7. Keep adjoining owners informed.
   Clear communication can prevent temporary works from being mistaken for unexpected permanent alterations.

What should Adjoining Owners look for?

If your neighbour is carrying out significant Party Wall works, it is reasonable to want to understand how your property will remain protected.

Questions may include:

• Will my building be temporarily exposed?
• Is excavation taking place directly alongside my foundations?
• How will the ground be supported?
• Is underpinning proposed?
• Will my roof or wall be exposed to rain?
• Does the contractor need access to my land?
• What happens if the method changes?
• Has a structural engineer considered the temporary stages?

The objective should not be to impose unnecessary construction requirements.

The aim is to ensure that foreseeable risks to adjoining property are properly considered.

Temporary works do not replace health and safety obligations

The Party Wall Act is only one part of the legal framework surrounding construction.

Compliance with a Party Wall Award does not replace obligations relating to:

• Building Regulations;
• construction health and safety;
• structural design;
• planning;
• building control; or
• other statutory requirements.

The Act itself requires works carried out under it to comply with statutory requirements.

If a building becomes dangerous, government Party Wall guidance recommends raising concerns with local authority building control, while relevant health and safety concerns may also involve the appropriate enforcing authority.

Common temporary works mistakes

1. Focusing only on the finished structural drawings

A permanent steel beam detail does not necessarily explain how the masonry will remain supported while the beam is installed.

2. Starting demolition before temporary support is agreed

Once structural elements have been removed, options become more limited.

3. Leaving walls exposed to rain

A party wall previously protected by an adjoining building may deteriorate rapidly if left unprotected.

4. Excavating too much ground at once

Construction sequencing can sometimes be just as important as foundation size.

5. Treating access as automatic

Temporary scaffold or protection on neighbouring land may require proper consideration under Section 8 or a separate agreement.

6. Allowing contractors to change methodology without telling anyone

A supposedly minor site change can materially alter the Party Wall risk.

7. Using vague phrases such as “support as necessary”

Complex work should be supported by meaningful information rather than relying entirely on contractor judgement after excavation begins.

Frequently Asked Questions

Does every Party Wall project require temporary works drawings?

No.

The information required should be proportionate to the complexity and risk of the works.

Simple structural alterations may need relatively little additional information, while basement or underpinning schemes may justify detailed temporary works proposals.

Can a Party Wall surveyor design the temporary works?

Normally, the structural design should be undertaken by an appropriately competent engineer or designer.

The Party Wall surveyor’s role is primarily to administer the Act and determine matters within its jurisdiction.

Can my neighbour demand any temporary protection they want?

Not automatically.

Protections should be reasonably necessary and proportionate to the works and risk.

The Party Wall procedure is intended to facilitate lawful works while protecting adjoining owners, not to impose unrelated construction requirements.

Can an Award specify how excavation is sequenced?

Where the sequencing is relevant to safely carrying out the notifiable works and protecting adjoining property, the surveyors may regulate the time and manner in which those works are undertaken.

Government guidance confirms that Awards can specify how and when works are carried out and require necessary protective measures.

Can the contractor ignore temporary works clauses in a Party Wall Award?

A Party Wall Award governs the works between the owners.

The building owner should ensure that relevant requirements are communicated to the contractor and followed.

What happens if the contractor discovers something unexpected?

Stop and review the affected element where necessary.

Unexpected foundations, ground conditions or structural details may require advice from the engineer and Party Wall surveyor before the works continue.

Does temporary scaffold automatically fall under the Party Wall Act?

No.

It depends on why the scaffold is needed.

Where access is necessary to execute works properly undertaken under the Act, Section 8 may provide relevant rights.

General scaffolding for unrelated works should not automatically be treated as statutory Party Wall access.

The key point

Party Wall projects are not only about the permanent structure.

The temporary stage of construction can be the point at which neighbouring property is most exposed.

Good Party Wall practice therefore looks beyond the finished architectural drawings.

It asks:

• What is being removed?
• What supports the building while it is removed?
• How is excavation kept stable?
• What happens if a wall becomes exposed?
• How will rain be kept out?
• Is neighbouring land needed?
• What happens if the construction method changes?

Answer those questions early and many potential disputes disappear before they reach site.

Need Advice on Temporary Works and Party Wall Matters?

Simple Survey assists Building Owners and Adjoining Owners throughout England and Wales with Party Wall matters ranging from straightforward extensions and loft conversions to more complex excavation, underpinning and structural projects.

If your project involves temporary propping, excavation support, structural alterations, exposed party walls or complicated construction sequencing, we can review the proposals and explain the Party Wall implications in clear, practical terms.

You may also find these Simple Survey guides useful:

• Section 2 of the Party Wall etc. Act 1996 Explained
• Party Wall Excavation and Section 6 Notices
• Party Wall Underpinning Explained
• What Drawings Are Needed With a Party Wall Notice?
• Understanding Party Wall Awards
• Party Wall Access Rights

Planning works that may affect a neighbouring property? Contact Simple Survey today or send us your architectural and structural drawings. We can review the proposals, identify the relevant Party Wall requirements and help you put the right process in place before construction begins.