Party Wall Notices are intended to be served before notifiable works begin. If a notice is issued after works have started (or after they have finished), it may help to open a dialogue and manage what happens next, but it does not “rewind time” or automatically legitimise work that should have been notified in advance.
The Party Wall etc. Act 1996 is a front-loaded procedure: it gives building owners rights to carry out certain works, but in return it requires advance notification and, where necessary, an Award that controls the works and protects the adjoining owner.
What people mean by “retrospective” Party Wall Notices
A notice is usually described as “retrospective” where it is served:
- after notifiable works have already started, or
- after the notifiable works have been completed, and the parties are trying to document what happened or deal with damage and fees.
The practical problem is that the Act is designed around proposed works and minimum notice periods.
The legal starting point: notice is required before you exercise the Act’s rights
For works to an existing party wall (the classic “section 2” works), the Act expressly requires notice before those rights are exercised. For example, section 3 provides that before exercising rights under section 2, the building owner shall serve a party structure notice describing the proposed work and the start date.
Government guidance also makes the position clear: if works start without notice being given, the adjoining owner can seek to stop the work by injunction or pursue other redress.
RICS guidance for homeowners is similarly direct: before you start the specific works you must either have the neighbour’s written agreement or a Party Wall Award.
Why this matters: minimum notice periods still apply
The Act’s procedures are built around lead-in time:
- Two months’ notice for works to an existing party wall/party structure (section 2 via section 3 notice)
- One month’s notice for new walls at the boundary (section 1) and qualifying excavations (section 6)
- The adjoining owner may agree in writing to an earlier start, but they are not obliged to.
So, if a building owner serves a notice “after the fact”, they have already missed the procedure the Act expects.
So is a retrospective notice “valid”?
It depends on what stage the project is at. In professional terms, it’s usually more helpful to think in three scenarios:
Scenario 1: Works are ongoing, but the notifiable stage has not started yet
This is more common than people realise. You may see general building activity (strip-out, deliveries, internal works), but the notifiable elements (cutting into the party wall for steels, underpinning, or excavation close to your foundations) may still be ahead.
In that situation, a notice served now is not really “retrospective” — it can still be a proper notice for the upcoming notifiable works, provided:
- it clearly describes what is proposed, and
- the statutory notice period is observed (unless you agree in writing to an earlier start).
Practical point: if you believe notifiable works are imminent, you should respond promptly and request clarity on programme and method, because the Act expects you to reply within 14 days.
Scenario 2: Notifiable works have started, and they are still continuing
This is where matters become more sensitive. Serving notice late does not erase the fact that the works began without the correct steps. Government guidance notes the Act has no enforcement procedures for failure to serve notice, but it remains a civil matter and the adjoining owner may seek an injunction or other legal redress.
However, a late notice can still be useful to:
- force the parties into the statutory dispute process for the remaining works, and
- put an Award in place to control how the ongoing works are completed.
If you are the adjoining owner, your options typically include:
- dissenting and appointing a surveyor (or proposing an agreed surveyor) to secure an Award quickly,
- requesting reasonably necessary protective measures (and, where appropriate, security for expenses),
- insisting on a Schedule of Condition being recorded as soon as possible (even mid-project it can still help narrow arguments), noting it is not mandatory but is strongly advised.
If you are the building owner, best practice is to pause the notifiable elements, regularise the process, and avoid letting the situation escalate into urgent legal action.
Scenario 3: The notifiable works are already complete
This is where the phrase “retrospective notice” causes most confusion.
Once the notifiable works are finished, you cannot realistically use a notice to give the adjoining owner the advance warning and the time to respond that the Act is designed to provide. Government guidance emphasises the adjoining owner can seek redress where work begins without notice.
At this stage, the practical focus often shifts to:
- inspection and evidence gathering,
- whether any damage has occurred and what caused it,
- how repairs/compensation should be dealt with,
- and whether any agreement can be reached to avoid wider dispute.
You can still agree a private document “after the event”, but it is important to understand that this is not the same thing as having followed the statutory process at the correct time.
A common misconception: “Can we just do a retrospective Award?”
You will sometimes hear the term “retrospective Award” used informally in the industry. What matters is whether the surveyor(s) have proper jurisdiction and whether the process is being used for remaining notifiable works (which can still be regulated), or whether it is essentially an attempt to paper over completed works.
If your priority is protection and resolution, a more reliable approach is often:
- record the condition carefully,
- put proper controls in place for any remaining notifiable works,
- and deal with damage/compensation in an evidence-led way.
What should you do next?
If you are the adjoining owner (you received the late notice)
- Respond in writing within 14 days (even if works are already happening).
- Ask for the drawings, structural details, excavation information and programme.
- If you are concerned, dissent and appoint a surveyor (or propose an agreed surveyor) to secure an Award for the remaining notifiable works.
- Request a Schedule of Condition and, where appropriate, consider security for expenses.
- If there is immediate risk or serious non-compliance, take advice quickly—Government guidance recognises injunction as a potential remedy where work has begun without notice.
If you are the building owner (you served late or have realised you should have served)
- Stop the notifiable elements until the position is clarified.
- Serve correct notices for any remaining notifiable works and allow the statutory periods unless written agreement is given to start earlier.
- Offer a Schedule of Condition and a clear point of contact to reduce anxiety and avoid escalation.
- Where dissent is likely, move promptly to an agreed surveyor or two surveyors so an Award can control the remainder of the works.
Speak to Howorth for practical, project-specific guidance
If you have received a Party Wall Notice after works have started, or you are trying to understand whether anything can still be regularised under the Act, we can help you map out the most proportionate next step.
Email mail@howorth.uk or call 07794 400 212.