THE PARTY WALL ACT EXPLAINE
A commentary on the Party Wall etc. Act 1996
FOURTH EDITION. FULLY REVISED AND UPDATED
THE PARTY WALL ACT EXPLAINE D
A commentary on the Party Wall etc. Act 1996
The Fourth Edition
© The authors and The Pyramus & Thisbe Society
Diagrams courtesy of Martin O’Shea
Illustrated by Pongo & Matelot
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Fourth Edition - 2025
ISBN 978-0-9558454-1-3
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Why “Pyramus & Thisbe”?
A brief history of the Society and its foundation
The Pyramus & Thisbe Club (named after the two lovers separated by a wall in Shakespeare’s A Midsummer Night’s Dream, “The Wall is down that parted their fathers”) was founded by John Anstey and fellow colleagues, in 1974 as a forum for discussion on all matters in connection with party walls.
By 2020 the Club’s membership had expanded twelvefold with members throughout England and Wales with numerous regional branches. It had established a reputation for knowledge, expertise and excellence and in 2022 a decision was taken to formally adopt the status of Learned Society and the club became The Pyramus & Thisbe Society.
Membership and participation in the Society is encouraged. For further information please visit our website pyramusandthisbesociety.org
The statements in this book are offered in good faith and whilst the publishers and authors have taken every care in preparing them no responsibility for loss occasioned to any person acting or refraining from acting as a result of any material included in or omitted from this publication can be accepted by the authors, the publishers, the officers or members of The Pyramus & Thisbe Society.
Introduction to the fourth edition
The first edition of The Party Wall Act Explained, widely known as The Green Book, published in 1993, was primarily aimed at practitioners as guide to future reform, but it also became the indispensable manual and guide for parliamentarians during the passage of the Bill that became the Party Wall etc. Act 1996.
The book received high praise during the House of Lords debate, with the late Lord Dubs describing it as “a clear explanation of legislation” and “a model of clarity.”
The book was re-written when the Party Wall etc. Act came into force nationally and this is its fourth edition. This, and all previous versions, have been written by leading practitioners in party wall matters and as such it represents the cumulative wisdom of many experts and aspires to explain the legislation with the clarity once praised in the House of Lords.
Work on the fourth edition was led by Fareed Fetto, National Chairman of the P&T Society, Michael Kemp and Martin O’Shea. In the course of their work widespread consultation took place amongst members, experienced practitioners and the legal profession. These contributions, from individuals too numerous to name here, are gratefully acknowledged.
It represents the most comprehensive revision to date and has been substantially re-written. Care has been taken to ensure that opinions expressed are either supported by robust case law or truly and fairly represent a wide consensus amongst practitioners. Deliberations were concluded in February 2025 and, where relevant, this publication reflects the writers’ understanding of current law and practice at that date.
Even with the greatest care, errors can slip through the editing process. Interpretation, current practice and the law develop over time. It is proposed to review this edition from time to time and provide appropriate updates on the P&T website.
History of Party Wall legislation
The Party Wall etc. Act 1996 was the first national Act, covering England and Wales, to regulate works to or close to party walls, party structures and fence walls. Prior to 1996 there were a number of local Acts in different parts of the country but only inner London had comprehensive legislation.
London’s legislation has a long history dating back over 800 years and the Party Wall etc. Act is very similar in content, scope and wording to Acts passed in London in the 19 th Century and in particular to the London Building Acts (Amendment) Act 1939. This legislation formed the framework for the current legislation.
This background is important to owners, practitioners and their advisers because much of the case law passed under predecessor legislation is still relevant to the current Act as is the way that predecessor legislation was operated by practitioners and the legal system.
The Act: A brief introduction
The Party Wall etc. Act 1996 provides owners of land and buildings with certain rights and obligations to other owners in relation to party structures and other structures in the proximity of boundaries. At the same time it provides a framework for a disciplined approach to exercising these rights. These matters are generally dealt with under Sections 1 to 5.
Section 6 introduces obligations on anyone excavating near another owner’s building or structure. Notices must be served and procedures followed.
There are provisions for compensation, for rights of entry and for the safeguarding of certain easements.
The Act lays down strict procedures for the resolution of disputes and these are in sections 10 to 14. They provide for the appointment of a surveyor or surveyors who have the power to settle disputes.
Later sections deal with the usual miscellaneous matters in an Act, including the fact that it may be an offence to step outside the Act’s provisions.
Important definitions are found in section 20. These should be read and understood before considering this commentary.
The Act refers to owners and surveyors using the pronouns “he” and “him”. This book uses “he” and “him” when directly quoting from the Act but uses gender neutral pronouns elsewhere.
The Party Wall etc. Act 1996
An Act to make provision in respect of party walls and excavation and construction in proximity to certain buildings or structures; and for connected purposes (18 July 1996).
Be it enacted by the Queen’s Most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same, as follows:-
Comment
The word “etc.” in the title refers to those provisions of the Act which deal with matters such as adjacent excavation, which are not strictly to do with party walls or structures.
The Act came into force on the 1st July 1997.
Section 1(1)(a)&(b)
Construction and repair of walls on line of junction
New building on line of junction S.1(1)(a)&(b)
1.(1) This section shall have effect where lands of different owners adjoin and -
(a) are not built on at the line of junction; or
(b) are built on at the line of junction only to the extent of a boundary wall (not being a party fence wall or the external wall of a building), and either owner is about to build on any part of the line of junction.
Interpretation
This section regulates proposals to construct walls either at, (meaning against, or up to) or astride (meaning over) the legal boundary between owners (known as the line of junction), where there exists at present no wall at all, or only a boundary wall positioned wholly on one owner’s land and belonging solely to that owner. In that case, if either owner wants to ‘build’ at, or astride the line of junction, they follow the procedures set out in the subsections below.
S.1 does not apply if there is an existing building at the line of junction, whether on one or other side.
S.1 does apply where a boundary wall already exists (on either side of the line of junction).
S.1 does not apply if there is a boundary wall astride the line of junction. Such a wall is a party fence wall under s.2 and subject to s.2 rights.
Section 1(1)(a)&(b)
Comment
The presence of an ordinary fence or hedge on the line of junction will not mean that the line of junction is “built on”.
It is generally accepted that the works described at s.1(2) to s.1(7) inclusive would be works in pursuance of the Act and so access would be available to the adjoining owner’s land subject to compliance with s.8 of the Act.
Some property deeds may define walls and fence walls as party walls regardless of the defined position of the line of junction. It is good practice to check property deeds whenever these are available.
New building on line of junction S.1(2)
(2) If a building owner desires to build a party wall or party fence wall on the line of junction he shall, at least one month before he intends the building work to start, serve on any adjoining owner a notice which indicates his desire to build and describes the intended wall.
Interpretation
See Diagrams 1 and 3 at Appendix I.
This type of wall would stand astride the line of junction, and therefore on the land of two owners (see definitions for a party fence wall and party wall in s.20).
Notice needs to be served not less than one calendar month before the works are due to commence. The possible consequences and actions following such a notice appear in the next subsection.
Comment
The notice has to indicate the desire to build and to describe the intended wall. No other requirements are given. S.3(1) sets out requirements for notices under s.2 and compliance with that section should avoid any argument over validity of s.1 Notices.
Section 1(3)(a)&(b)
New building on line of junction S.1(3)(a)&(b)
(3) If, having been served with notice described in subsection (2), an adjoining owner serves on the building owner a notice indicating his consent to the building of a party wall or party fence wall —
(a) the wall shall be built half on the land of each of the two owners or in such other position as may be agreed between the two owners; and
(b) the expense of building the wall shall be from time to time defrayed by the two owners in such proportion as has regard to the use made or to be made of the wall by each of them and to the cost of labour and materials prevailing at the time when that use is made by each owner respectively.
Interpretation
Having received a notice the adjoining owner may agree to the proposal by serving a notice of consent. See subsection (4) for what happens if the adjoining owner does not consent.
If the adjoining owner consents to a party wall/fence wall, it may be built half on each side of the line of junction, although the owners are free to decide exactly where to build it. Paragraph (b) covers the eventuality that one owner may make more use of the wall at the time of its construction than the other.
Indes of key terms
Index of key terms
This index lists only the most relevant or important references to certain words and terms. Indexing every single reference would create an unwieldy and impractical document.
Access 3, 9, 69-75
< for adjoining owners etc acting as building owners 75
< for building owners etc 69-71
< for surveyors 74-75
Accounts 121-123
Adjacent excavation 47-60
< explanatory drawings 158-163
Adjoining occupier
9,13, 40-41, 54, 60-61, 63-64, 65, 72, 75, 108, 128
< definition 106
Adjoining owner
< definition 136
< multiple 55, 136, 137
Agreed Surveyor 78, 79, 83, 85, 93
Appeal 99, 103
Appointing Officer 90, 138
Appointments 78-82
Arches over passageways 18
“As built” drawings 59
Award
< binding 102, 103
< content 93, 95, 96, 97, 98,
< example 96, 160-167
< ex parte 87-89
< service 99
Boundary disputes 14, 80
Boundary wall explanatory drawing 153
Building or structure, meaning 49, 174
Change of ownership 142,143
Chimney breast/stack 28, 30, 42
Compensation 13, 63, 64
Concrete overspill 114
Consent
< conditional 45, 46
< general requirements of 45, 46
< s.1, 5-8
< s 3, 39-41
< s.5, 45-46
< s.6, 57
< special foundations 66-67
Costs see also “Expenses”
< apportionment 15, 17, 27
< award 95, 97
< counter notice 42
< special foundations 103
Counter Notice 42-43
Courts 86,102,103,141,149
Court cases 39, 58, 61, 78, 89
Crown property 134, see also “Exemptions”
Cut away/into/remove 20-24
Damage 63, 107
< building owners obligation to make good 110
< right to payment in lieu of 110
Damp proof course 21
Dangerous Structure Notice 40-51
Debt. 131
Decoration(s) 30,32,33
Defect/want of repair
16, 17, 30, 31, 35, 106, 107
Definitions 15,18, 136-149
< adjoining owner 136
< adjoining occupier 136
< appointing officer 138
Indes of key terms
< building or structure 49, appendix 3
< building owner 139
< foundation 140
< owner 141
< partition 18, 145
< party fence wall 2, 144
< party structure 145
< party wall 13, 146
< special foundations 148
< surveyor 149
Demolish/demolition 19, 77
De Novo 83
Deviations and variations 68
Diagrams see appendix 1, 152-164
Dispute/s
< section 1. 8, 9, 12, 14
< section 2. 25
< section 3. 39-40
< section 5. 45-46
< section 6. 52, 55, 57, 58
< section 7. 63, 64
< section 8. 75
< section 10. 79-103
< section 11. 104, 113
< section 12. 117, 118, 120
< section 13. 121, 122
Indes of key terms
Dissent 8, 45, 57
Disrepair 16, 17, 27
Disturbance 108
Dormers 16
Due diligence 8, 58
Easements 23, 24, 76-77
Effectively 87
Electronic communications 124-5
Embassies 135
Emergency 72, 75
Enclosure see “Subsequent use of”
Engineers and other consultants 64, 97, 98, 116
Enter/entry see “Access”
Excavation(s) 67-60
< safeguarding 51
< services 48
< shallow 48
< trial holes 49
Exemptions 132-135
Ex Parte see “Award”
Expenses 132-136
< apportionment accordance to use made of, 5, 105-107
< liability of adjoining owner 109, 112, 115
< liability of building owner 104, 108, 109, 110, 113
< settlement of, see “Accounts”
Expose 29
External wall 2, 7, 15, 16, 23, 30, 50, 53, 106
Fair allowance 19, 62, 108
Fees 95, 97, 98, 131
Flashing 21, 25
Flue(s) 23, 30,31, 42, 76, 77
Footings/foundation(s) see also “Special foundations” and “Concrete overspill”
< cutting away of projections 23
< shallow 48, 51, 113-114, diagrams 11-12, 161, 162
Hinder(s) 129
Hoardings see “Lay open”
Impartiality 79, 84, 149
Implementation date 1
Incapable 83, 86
Inconvenience 19, 62, 64, 66, 108
see also “Unnecessary inconvenience“
Injunction 36, 76, 78, 137, 147
Injury 60, 74
Insulation 29
Inns of Court 132-133
Inspections 97
Jurisdiction 93, 95
Land registry search 37
Lay lopen 19, 65, 108
Liability 60
Light 76
Line of Junction 1-14
< access for works 3, 69
< consent 5
< dispute 14
< status 2
Local authority 90, 91, 138, 149
Loss 9, 60, 61, 63, 64, 108
Making good payment in lieu of 30-33, 110, 111
Materials for raising 16
Modifications 135
Neglect(ed)(s)
Indes of key terms
49, 51,83, 84, 87, 88, 89, 90
Notice(s)
< access 72,73,75
< consent to 15, 55, 67
< counter notice 43
< line of junction 4, 9
< requirements of 36-7, 56
< retrospective 93
< s.2 36-37
< s.6 55-58
< service 36, 124, 127
Obstructs 129
Offence(s) 73, 128-130
Openings 21, 22
Owners
< change of, 142-144
< definition of 141-143
< identifying 37
< multiple 52, 54, 136, 137, 141
Overhanging 24
Parapet 25, 34, 109
Partitions 18, 145
Indes of key terms
Party fence wall see also “Line of junction”
< construction of 1 to 14
< definition 3, 15, 144
< explanatory drawing 153
< projection of footings 11, 12, 13
< rights of entry 3, 9
< works to existing 16, 17, 22, 23, 27, 28
Party Wall etc Act v, vii, 1, 151
Party wall type a and b:
< definition 146, 147
< diagrams 153-158
Payment in lieu 110
Plans and sections
36, 43, 56, 59, 63
Police officer 71
Power and Kyson v Shah 2023 court of appeal 40, 78, 93
Projecting/projection(s) 11, 23, 24, 32, 114,146
Protection
< hoardings 65
< weather 29
Proportion see “Expenses”
Pyramus and Thisbe Society iii, appendix 3
Pyramus and Thisbe Society guidance notes see Appendix 3
Raise, raising 16, 27
Reasonable
> costs 97
> inspections 97
Rebuild(ing) 17-19, 27, 28, 65, 77
Recovery of sums 131
Reduce(d), reducing 20-22, 28
Refuse(s) 84, 87-89, 90, 92, 128
Repair see “Defect”
Responsibilty
> damage 30-33
> expenses 104-107
Security 117, see also “Expenses”
< amount 117
< nature of 117, 118
< time limits 117, 119, 120
Service see “Notice”
> award 99
> documents 124-127
> notices 124-127
Special foundations
< consent needed 65, 67
< counter notice 42
< definition 148
< details of 11, 37
< future cost implications 113, 114
< notice requirements 11, 36
Statute/statutory:
< cannot vary 38, 39,
< comply with 16, 68
< deemed compliance with 35
< duty 82
< instrument 150
< notice 41
< provisions 150, 151
< requirements 18, 38, 68, 81
< role (of surveyors) 93-102
Subsequent use 5, 6, 115, 116
Surveyors
< appointment of 77-92
< duties 93-102
< in writing 81
< replacement of 81, 83-89,92
< selection 90, 92
Thicken/thickness 16, 20
Indes of key terms
Third surveyor
< award 100, 101
< costs of award 100
< permanence of appointment 81
< referral 94
< replacement of 92
< selection of 78
Time and manner 95
Trial holes see “Excavation”
Ultra vires 102
Unauthorised works 36
Underpin/underpinning 16, 51, 52. 158.159. 161. 162
Unnecessary inconvenience 9, 44, 61, 62
Variations see “Deviations”
Want of repair see “disrepair”
Weathering 29
Weather-proofing 25
The fourth edition of THE PARTY WALL ACT EXPLAINED