The Act came into force on 1 July 1997 and applies throughout England and Wales.

It provides a framework for preventing and resolving disputes in relation to party walls, boundary walls and excavations near neighbouring buildings. It is based on some tried and tested provisions of the London Building Acts, which applied in inner London for many decades before the Act came into force.

Anyone intending to carry out work (anywhere in England and Wales) of the kinds described in the Act must give Adjoining Owners notice of their intentions. Where the intended work is to an existing party wall (section 2 of the Act) a notice must be given even where the work will not extend beyond the centre line of a party wall.

Adjoining Owners can agree with the Building Owner’s proposals or reach agreement with the Building Owner on changes in the way the works are to be carried out, and in their timing. Where there is no written consent or agreement, the Act provides for the resolution of ‘disputes’.

• Various work that is going to be carried out directly to an existing party wall or structure (see Questions 4 to 19)
• New building or free standing wall at or astride the boundary line between properties (see Questions 20 to 25)
•  Excavation within 3 or 6 metres of a neighbouring building(s) or structure(s), depending on the depth of the hole or proposed foundations (see Questions 26 to 29).

 The Act recognises two main types of party wall.
 
 Party wall type (a)
 
 A wall is a "party wall" if it stands astride the boundary of land belonging to two (or more) different owners.
 Such a wall:

•  is part of one building (see diagram 1), or
•  separates two (or more) buildings (see diagram 2), or
•  consists of a “party fence wall” (see diagram 3) 

A wall is a "party fence wall" if it is not part of a building, and stands astride the boundary line between lands of different owners and is used to separate those lands (for example a garden wall). This does not include such things as wooden fences.
 
 Party wall type (b)
 
 A wall is also a “party wall” if it stands wholly on one owner’s land, but is used by two (or more) owners to separate their buildings (see diagram 4).
 
An example would be where one person has built the wall in the first place, and another has butted their building up against it without constructing their own wall. Only the part of the wall that does the separating is "party" - sections on either side or above are not "party".
 
The Act also uses the expression "party structure". This is a wider term, which could be a wall or floor partition or other structure separating buildings or parts of buildings approached by separate staircases or entrances (for example flats) – see diagram 5.

The Act provides a Building Owner, who wishes to carry out various sorts of work to an existing party wall, with additional rights going beyond ordinary common law rights. Section 2 of the Act lists what work can be done. The most commonly used rights are:

• to cut into a wall to take the bearing of a beam (for example for a loft conversion), or to insert a damp proof course all the way through the wall
• to raise the height of the wall and/or increase the thickness of the party wall and, if necessary, cut off any projections which prevent you from doing so
• to demolish and rebuild the party wall
• to underpin the whole thickness of a party wall
• to protect two adjoining walls by putting a flashing from the higher over the lower, even where this requires cutting into an Adjoining Owner’s independent building. 

If you intend to carry out any of the works mentioned in Question 4, you must inform all Adjoining Owners - see Questions 7 and 8. You must not even cut into your own side of the wall without telling the Adjoining Owners of your intentions - but see Question 6.

The Act contains no enforcement procedures for failure to serve a notice. However, if you start work without having first given notice in the proper way, Adjoining Owners may seek to stop your work through a court injunction or seek other legal redress.

An Adjoining Owner cannot stop someone from exercising the rights given to them by the Act, but may be able to influence how and at what times the work is done - see Question 10.

The Act also says that a Building Owner must not cause unnecessary inconvenience. This is taken to mean inconvenience over and above that which will inevitably occur when such works are properly undertaken.

The Building Owner must provide temporary protection for adjacent buildings and property where necessary. The Building Owner is responsible for making good any damage caused by the works or must make payment in lieu of making good if the Adjoining Owner requests it.

In specific circumstances where party walls are demolished and rebuilt (s.2(2)(b) of the Act) section 11(5) provides that the cost of the work shall be shared. Where use is made of party walls previously built at the cost of the Adjoining Owner, the Act makes provision for a fair payment to be made to the Adjoining Owner.

Some works on a party wall may be so minor that service of notice under the Act would be generally regarded as not necessary.
Things like:

• drilling into a party wall to fix plugs and screws for ordinary wall units or
• shelving
• cutting into a party wall to add or replace recessed electric wiring and sockets replastering

may all be too minor to require a notice under the Act.
 
The key point is whether your planned work might have consequences for the structural strength and support functions of the party wall as a whole, or cause damage to the Adjoining Owner’s side of the wall. If you are in doubt about whether your planned work requires a notice you might wish to seek advice from a qualified building professional.

Essentially, an Adjoining Owner is anyone with an interest greater than a yearly tenancy in the adjoining property.

The adjoining property may have a freehold owner, a leasehold owner and/or a long term tenant, each or all of whom may be an 'Adjoining Owner' under the Act.

Where there is more than one owner of the property, or more than one adjoining property, it is your duty to notify all Adjoining Owners.

It is obviously best to discuss your planned work fully with the Adjoining Owners before you (or your professional adviser on your behalf) give notice, in writing, about what you plan to do. If you have already ironed out possible snags with your neighbours, this should mean that they will readily give consent in response to your notice. You do not need to appoint a professional adviser to give the notice on your behalf.
 
 Whilst there is no official form for giving notice under the Act, your notice must include the following details:

• your own name and address (joint owners must all be named, e.g. Mr A & Mrs B Owner)
• the address of the building to be worked on (this may be different from your main or current address)
• a full description of what you propose to do (it may be helpful to include plans but you must still describe the works)
• when you propose to start (which must not be before the relevant notice period has elapsed).

The notice should be dated and it is advisable to include a clear statement that it is a notice under the provisions of the Act.
 
 (It is advisable to seek professional advice prior to issuing a Notice, as to whether the intended works are notifable, as once a notice is issued the process has to complete through to an Award, incurring fees).
 
 You may deliver the notice to the Adjoining Owner(s) in person or send it by post. Where the neighbouring property is empty or the owner is not known, you may address the notice to "The Owner", adding the address of the premises, and fix it to a conspicuous part of the premises.

You do not need to tell the local authority about your notice.

At least two months before the planned starting date for work to the party wall, and one month for a Party fence wall. The Adjoining Owner may agree to allow works to start earlier but is not obliged to even when agreement on the works is reached. The notice is only valid for a year, so do not serve it too long before you wish to start.

A person who receives a notice about intended work may:

• give his consent in writing, or
• dissent from the works proposed, in writing (the procedure explained in Question 11 below, comes into play or
• do nothing.

If, after a period of 14 days from the service of your notice, the person receiving the notice has done nothing, a dispute is regarded as having arisen - see Question 11.
 
 A person who receives notice about intended work may, within one month, give a counter-notice setting out what additional or modified work he would like to be carried out for his own benefit. A person who receives a notice, and intends to give a counter-notice, should let the Building Owner know within 14 days.
 
 If you receive a counter-notice you must respond to it within 14 days otherwise a dispute is regarded as having arisen - see Question 11.
 
 As mentioned in Question 8, your notice should not come as a surprise. If you have already ironed out possible snags with your neighbours, this should mean that they will readily give consent in response to your notice.
 
 It should be noted that where consent is given you are not relieved of your obligations under the Act, for example to avoid unnecessary inconvenience or to provide temporary protection for adjacent buildings and property where necessary. The notice of consent is simply confirmation that, at that time, there is nothing 'in dispute'. Should a difference arise at a later date (for example in respect of damage caused) the procedure explained in Question 11 then comes into play.

The best way of settling any point of difference is by friendly discussion with your neighbour. Agreements must always be put in writing. It is prudent to have a Party Wall Award drawn up even with consent, to aviod disputes during or after the works which may result in any defects/problems being blamed on you as Building Owner. The Party Wall Award would include times, access and a detailed schedule of condition prior to commencing.

If you cannot reach agreement with the Adjoining Owners, the next best thing is to agree with them on appointing what the Act calls an "Agreed Surveyor" to draw up an "Award". The Agreed Surveyor should NOT be the same person that you intend to employ or have already engaged to supervise your building work - see Question 12.

Alternatively, each owner can appoint a surveyor to draw up the award together. The two appointed surveyors will select a third surveyor (who would be called in only if the two appointed surveyors cannot agree).

In all cases, surveyors appointed under the dispute resolution procedure of the Act must consider the interests and rights of both owners and draw up an award impartially.

Their duty is to resolve matters in dispute in a fair and practical way.

Where separate surveyors are appointed by each owner, the surveyors must liaise with their appointing owners and put forward the respective owners’ preferred outcome. However, the surveyors do not act as advocates for the respective owners. They must always act within their statutory jurisdiction and jointly prepare a fair and impartial award.

The term "surveyor" is defined in the Act as any person who is not a party to the matter. The surveyor should have a good knowledge of construction and of administering the Act. As Chartered Surveyors and members of The Pyramus & Thisbe Club we offer first class service in this regard.
 
 You and your neighbour should not choose the person you have engaged to supervise the building works to be the "Agreed Surveyor". It is difficult to be the person responsible for ensuring the completion of the work at the same time as giving full regard to the rights of the neighbours. Your neighbour may also be less inclined to agree to jointly appoint a person to resolve a dispute if that person is already engaged by you in another capacity. 

The surveyor (or surveyors) will prepare an "award" (also known as a "party wall award"). This is a document which:

• sets out the work that will be carried out
• says when and how the work is to be carried out (for example, not at weekends if the buildings are domestic properties)
• specifies any additional work required (for example necessary protection to prevent damage)
• often contains a record of the condition of the adjoining property before the work begins (so that any damage to the adjoining land or buildings can be properly attributed and made good)
• allows access for the surveyor(s) to inspect the works while they’re going on (to see that they are in accordance with the award).

It is a good idea to keep a copy of the award with your property deeds when the works are completed. 

The surveyor (or surveyors) will decide who pays the fees for drawing up the award and for checking that the work has been carried out in accordance with the award. Usually the Building Owner will pay all costs associated with drawing up the award if the works are solely for his benefit. 

The Award is final and binding unless it is amended by the Court. Each owner has 14 days to appeal to the county court against an award. An appeal should only be made to the county court if an owner believes that the surveyors’ determination is fundamentally wrong.

An appeal should not be undertaken lightly and an owner considering an appeal may well wish to seek legal advice.

Your agreement with the Adjoining Owner, or the award in the event of a dispute, will set this out.

The general principle in the Act is that the Building Owner who initiated the work pays for it if the works are solely for his benefit. However, there are cases where the Adjoining Owner may pay part of the cost, for example:

• where work to a party wall is needed because of defects or lack of repair for which the Adjoining Owner may be responsible (in full or in part).
• where an Adjoining Owner requests that additional work should be done for his benefit.

Where the dispute resolution procedure is called upon, the award may deal with apportionment of the costs of the work. The dispute procedure may be used specifically to resolve the question of costs if this is the only matter in dispute.

If a dispute has arisen and the neighbouring owner refuses to appoint a surveyor under the dispute resolution procedure, you can appoint a second surveyor on his behalf, so that the procedure can go ahead - see Questions 11 and 12. In these circumstances you will not be able to appoint an “agreed surveyor”. Your own surveyor will advise you on the appointment of a second surveyor on behalf of the Adjoining Owner.

Under the Act, an Adjoining Owner and/or occupier must, when necessary, let in your workmen and your own surveyor or architect etc., to carry out works in pursuance of the Act (but only for those works), and allow access to any surveyors appointed as part of the dispute resolution procedure.
 
 You must give the Adjoining Owner and occupier notice of your intention to exercise these rights of entry. The Act says that 14 days’ notice must usually be given. It is an offence, which can be prosecuted in the magistrates’ court, to refuse entry to or obstruct someone who is entitled to enter premises under the Act, if the offender knows or has reasonable cause to believe that the person is entitled to be there.
 
 If the adjoining property is closed (for example an unoccupied property) your workmen and your own surveyor or architect etc. may enter the premises after following proper procedures if they are accompanied by a police officer.
 
 You should discuss access for other works with your neighbour. It is often in the best interests of the Adjoining Owner to allow access voluntarily to build a wall or carry out works for which there is no statutory right of access, as this will allow a better finish to the side of the wall that they will see.

Adjoining Owners’ rights include:

• appoint a surveyor to resolve any dispute;
• require reasonably necessary measures to be taken to protect their property from foreseeable damage;
• not to suffer any unnecessary inconvenience;
• be compensated for any loss or damage caused by relevant works;
• ask for security of expenses before you start significant work so as to guard against the risk of being left in difficulties if you stop work at an inconvenient stage.

If you plan to build a party wall or party fence wall astride the boundary line, you must inform the Adjoining Owner by serving a notice - see Questions 7 and 8. You may want to base your notice on Example Letter 4. However, there is no right to build astride the boundary without your neighbour's agreement in writing - see Question 22.

You must also inform the Adjoining Owner by serving a notice if you plan to build a wall wholly on your own land but up against the boundary line.

The Act contains no enforcement procedures for failure to serve a notice. However, if you start work without having first given notice in the proper way, Adjoining Owners may seek to stop your work through a court injunction or seek other legal redress.

At least one month before the planned starting date for building the wall. The notice is only valid for a year, so do not serve it too long before you wish to start.

If the Adjoining Owner agrees within 14 days to the building of a new wall astride the boundary line, the work (as agreed) may go ahead. The expense of building the  wall may be shared between the owners where the benefits and use of that wall will be shared.
 
 The agreement must be in writing and should record details of the location of the wall, the allocation of costs and any other agreed conditions.
 
 If the Adjoining Owner does not agree, in writing, within 14 days, to the proposed new wall astride the boundary line, you must build the wall wholly on your own land, and wholly at your own expense. However, you have a right to place necessary footings for the new wall under your neighbour’s land – see Question 23 - subject to compensating for any damage caused by building the wall or laying the
 foundations. There is no right to place reinforced concrete under your neighbour’s land without their express written consent.
 
 You may start work one month after your notice was served.

Unless your neighbour objects, you may start work one month after your notice was served. You have the right to place footings and foundations extending under the Adjoining Owner’s land. However, there is no right to place reinforced concrete foundations under your neighbour’s land without their express written consent.
 
 The wall will be built wholly at your own expense and you will have to compensate any Adjoining Owner for any damage to his property caused by the building of the wall, or the placing of footings and foundations under his land.

If there is a disagreement about any work of the kinds covered in Questions 22 and 23, including compensation, the dispute can be settled under the procedure described in Questions 11 to 17.

The surveyor(s) can assist the owners in reaching agreement but cannot decide who is right if the boundary location is in dispute (see Questions 37 and 38 in Part 4 of this booklet).

See Question 18. 

If you plan to:
- excavate, or excavate and construct foundations for a new building or structure, within 3 metres of a neighbouring owner’s building or structure, where that work will go deeper than the neighbour’s foundations (see diagram 6); or
- excavate, or excavate for and construct foundations for a new building or structure, within 6 metres of a neighbouring owner’s building or structure, where that work will cut a line drawn downwards at 45° from the bottom of the neighbour’s foundations (see diagram 7)
 
 you must inform the Adjoining Owner or owners by serving a notice - see Questions 7 and 8.
 
 Note that, for the purposes of section 6 of the Act, “Adjoining Owners” may include your next-but-one neighbour if they have foundations within 6 metres.
 
 The notice must state whether you propose to strengthen or safeguard the foundations of the building or structure belonging to the Adjoining Owner. Plans and sections showing the location and depth of the proposed excavation or foundation and the location of any proposed building must also accompany the notice.
 
 The Act contains no enforcement procedures for failure to serve a notice. However, if you start work without having first given notice in the proper way, Adjoining Owners may seek to stop your work through a court injunction or seek other legal redress. 

At least one month before the planned starting date for the excavation. The notice is only valid for a year, so do not serve it too long before you wish to start.

If the Adjoining Owner gives written notice within 14 days agreeing to the proposed works, the work (as agreed) may go ahead. If the Adjoining Owner does not respond, or objects to the proposed work, a dispute is regarded as having arisen - see Questions 11 to 17.

After the work has been completed, the Adjoining Owner may request particulars of the work, including plans and sections.

See Question 18. 

If your neighbour intends to carry out building work which involves one of the following categories:

• work on an existing wall or structure shared with another property (section 2 of the Act) - see Questions 4 to 18
• building a free standing wall or a wall of a building up to or astride the boundary with a neighbouring property (section 1 of the Act) - see Questions 19 to 24; or
• excavating near a neighbouring building (section 6 of the Act) - see Questions 25 to 28
  

they must notify you in writing before they start work see Question 8, 20 and 26. 

If you receive a notice from your neighbour you should reply to it in writing within 14 days of receiving it. You do not need to appoint a professional adviser to respond to the notice on your behalf.
 
 You can agree or disagree with what is proposed.
 
 If you do not respond to a notice about an intended new wall built up to (but not astride) the line of junction, the work can commence after the one month notice period. The Building Owner may place any necessary footings and foundations under your land (but not reinforced concrete foundations without your prior written consent).
 
 If you do not respond, in writing, within 14 days to a notice about an intended new wall built astride the line of junction, the Building Owner must build the wall entirely on his own land. The work can commence after the one month notice period. The Building Owner may place any necessary footings and foundations under your land (but not reinforced concrete foundations without your prior written consent).
 
 If you receive a notice about work to an existing party structure, or a notice about excavations within 3 or 6 metres of your foundations, and you have not responded, in writing, within a period of 14 days from receipt of the notice, a dispute is regarded as having arisen. The procedure explained in Questions 11 to 15 then formally comes into play.
 
 If you disagree with the work described in a notice under the Act you should explain why. The Building Owner can then consider your objection and perhaps amend his proposal. Agreement might then be reached, without the need to use the formal dispute resolution procedure.

You should let your neighbour know (in writing) about the Act. 

The Act contains no enforcement procedures for failure to serve a notice. However, if your neighbour starts work without having first given notice in the proper way, you may seek to stop the work through a court injunction or seek other legal redress. You may wish to take professional legal advice before commencing such action. 

See Questions 11 - 17.
 
Where the proposed works are minor and/or not intrusive on your building or land, you may have only minor objections that you cannot agree or perhaps simply want some assurance that the correct procedures are followed.
 
 In these circumstances, and particularly in residential circumstances where surveyors fees would significantly increase the project costs, the appointment of an agreed surveyor to resolve the dispute is preferable, especially so if the proposed surveyor is not otherwise involved in your neighbour’s project.

See Question 18.
 
Even where you object to what your neighbour is building on his land, it is often to your benefit to allow access, for example for scaffolding or to allow pointing of the wall, as the wall will probably be visually more acceptable if access is given.

If there is a risk that you will be left in difficulties if the Building Owner stops work at an inconvenient stage, you can ask him, before he starts work, to make available an amount of money that would allow you to restore the status quo if he fails to do so.

The money remains his throughout, but if, for example, you need to have a wall rebuilt, you, or more commonly the surveyors, can draw on that security to pay for the rebuilding.

This provision is usually reserved for particularly intrusive or complex works.

No. The Act does not change the ownership of any wall, nor does it change the position of any boundary. Boundaries can still run through the centre of a wall, so that each owner may technically own half of a wall. However, it may help in understanding the principles of the Act if owners consider themselves joint owners of the whole of a party wall rather than the sole owner of half or part of it.
 
 The Act sets out what rights an owner has in relation to works to a party wall and what he is obliged to do before he can exercise those rights.

No. The Act does not contain any provision that could be used to settle a boundary line dispute. Such disputes can be resolved through the courts or through alternative dispute resolution procedures (which may be simpler, quicker and cheaper), for example mediation, decision by an independent expert or arbitration.

Yes, but only in relation to works covered by the Act, and only when the correct notices have been given and the procedures correctly followed.

No, so long as the Adjoining Owner agrees, in writing, to the work starting earlier than as stated in the notice.

It is good practice to prevent debris collecting in (or animals entering) the small gap between two adjacent independent structures and the Act allows for any works “incidental to the connection of a structure with the premises adjoining it”. There are several proprietary products that can effectively seal the gap between two buildings without having to cut into or permanently fix to either building. The Building Owner erecting the second structure would usually carry out this work.