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Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
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Party wall · London & Hertfordshire
Party wall notices and surveyors: when the Act applies, what it costs, and how not to lose three months
By Anderson & the LCCL Construction Team
Finchley N3 · Design & build, LABC award winners 2024 and 2026
If you share a wall with a neighbour and you are extending, converting the loft or digging a basement, the Party Wall etc. Act 1996 almost certainly applies. It is not planning and it is not building control — it is a separate legal process between you and next door, and it is the item that most often delays a London project when it is left late. LCCL serves the notices at cost as part of every design and build contract and manages the surveyor process where a neighbour dissents. This page explains when the Act applies, what the notices and awards cost in 2026, the timeline, and how we run it so it never holds the build.
Quick answer
Notices served at cost — £300 each — within every LCCL contract. If a neighbour dissents and a surveyor is appointed, awards typically start from £750 per neighbour, and you pay both surveyors' fees.
Separate from planning and building regulations. The Act applies whether or not you need either.
Two months' notice for work to the wall or excavation; one month for a new wall on the boundary. Left late, the process can add three months to a semi or terrace project.
A free 30-minute phone call with our team, no obligation.
Notices
£300 each, at cost
Surveyor award
From £750 per neighbour
Notice period
1–2 months
Included in
Every design & build contract
LABC Building Excellence Award 2024
Best Residential Extension in London — Bohun Grove, East Barnet EN4: rear extension, hip-to-gable loft conversion and whole-house renovation
LABC Building Excellence Awards 2026
London Regional Winner, Best Conversion or Alteration — Weech Road, Hampstead NW6: penthouse loft conversion and full renovation
One contract
Architecture, structural engineering, planning, construction and project management — all under one contract
Guaranteed & insured
12-month workmanship guarantee; 10-year LABC structural warranty
What LCCL's party wall service includes
Available on its own, or included in every LCCL design and build contract.
A check at survey stage of which neighbours are affected and which sections of the Act apply — shared wall, excavation within 3 m or 6 m, new wall on the boundary
Notices drafted and served on your behalf at cost (£300 each) — Section 1, 3 or 6 as the work requires — with the drawings and structural details the neighbour is entitled to see
Served at design stage, so the notice period runs while the planning application or lawful development certificate is in
A conversation with the neighbours, with the drawings, before the letter lands — we will come with you
Where the neighbour consents: the consent recorded and a schedule of condition of their property offered so there is no dispute later
Where the neighbour dissents: the appointment of surveyors managed, the award agreed, the schedule of condition recorded — including an agreed surveyor acting for both sides where the neighbour is willing
The award's working hours, access and protection requirements built into the site programme
Final inspection and sign-off against the schedule of condition at completion
All notices, consents, awards and schedules in your handover pack for when you sell
What does the party wall process cost in London in 2026?
Notices are at cost. Surveyors' fees only arise if a neighbour dissents — and you pay for both sides.
Outcome
What happens
Guide cost
Neighbour consents in writing within 14 days
No surveyor; a schedule of condition is still sensible
£300 per notice (at cost), nothing more
Agreed surveyor — one surveyor acts for both of you
Award and schedule of condition by one surveyor
From £750 per neighbour
Two surveyors — the neighbour appoints their own
Two surveyors agree the award; you pay both fees
£1,500 – £3,000+ per neighbour, more on a basement
What triggers a notice
Section of the Act
Notice period
Cutting into, raising or underpinning a shared wall — loft steels, chimney removal, basement
Section 2 (works to a party structure)
2 months
Excavating within 3 m of a neighbour's foundations and deeper than them — most extension footings — or within 6 m on a basement
Section 6 (adjacent excavation)
1 month
Building a new wall on or astride the boundary — a side return or extension flank wall
Section 1 (line of junction)
1 month
What the £300 covers: drafting and serving the notice with the drawings and structural details the Act requires, tracking the 14-day response, and recording consent. What you pay if a surveyor is appointed: the surveyors' fees for the award and the schedule of condition — the building owner pays both sides. The figure on your itemised estimate is the figure you pay — nothing is added afterwards. Every extension, loft and basement estimate from LCCL lists the notices and an allowance for awards, so the cost is visible before you sign.
What moves the cost: the number of neighbours (a terrace has two, a semi one, a corner terrace three); whether they consent; whether they accept an agreed surveyor; and the scale of the work — a basement dig with underpinning is the case where two surveyors and a detailed award are the norm and the fees run into thousands. A conversation over the fence with the drawings in your hand is the single cheapest thing you can do.
Party wall by project type
Extensions on a semi or terrace
Almost always Section 6 — the new foundations are within 3 m of the neighbour's and deeper — and Section 1 where the flank wall sits on the boundary. One notice per affected neighbour; most consent.
Loft conversions
Section 2 — the new floor steels bear on the party wall and the dormer or gable is built against it. On a terrace, both neighbours; on a semi, one. The neighbours' objection is usually informal rather than formal — talk to them first.
Basements
Every section at once: underpinning the shared wall (Section 2), excavation within 3 m or 6 m (Section 6), and often a new wall on the line of junction. Two surveyors, a detailed award and a full schedule of condition are the norm, and the process is started with the planning application, not after it.
Planning
How the party wall process fits the programme
It runs alongside the approvals, not after them. That is the whole trick.
Stage
When
Time
What we do
1. Check who is affected
At the measured survey
Day 1
Which neighbours, which sections, which notices
2. Serve notices
With the planning or LDC submission
14 days to respond
Notices with drawings and structural details; a conversation with the neighbours first
3. Consent or dissent
Day 14
—
Consent recorded, or surveyors appointed (agreed surveyor where possible)
4. Award and schedule of condition
During the notice period
4–8 weeks
Award agreed, condition of the neighbour's property recorded, requirements built into the programme
5. Start on site
After the notice period and the award
—
Never before — starting early puts you in the wrong
Planning & building regulations
The party wall process is separate from both
Planning permission or a lawful development certificate does not satisfy the Party Wall Act, and neither does building-regulations approval — they are three separate consents from three different parties (the council, building control and your neighbour). A project needs all three that apply to it, and the party wall process is the only one with a fixed notice period you cannot shorten.
We run all three from the same drawings, at the same time, so the two-month notice period is spent waiting for the planning decision rather than added on afterwards.
The Act gives a neighbour 14 days to consent; silence counts as dissent and triggers surveyors. Most neighbours consent when they have seen the drawings and met the people doing the work — which is why we go round with you before the letter arrives. Where a neighbour appoints their own surveyor, the award still usually lands inside the two-month notice period if the notices went out at design stage.
Projects where we ran the party wall process
Bohun Grove, East Barnet EN4 — rear extension, hip-to-gable loft and whole-house renovation
LABC 2024 Best Residential Extension in London
Semi-detached family home One programme loft + extension + renovation
A total renovation of a family semi: a rear extension opening into a full-width kitchen and dining space with floor-to-ceiling glazing and skylights, a hip-to-gable loft conversion with a rear dormer, two Lusso Stone bathrooms, enlarged bedrooms, new windows throughout, a regulated outbuilding and landscaping.
Because the loft and extension ran under one contract, the steelwork for the open-plan ground floor and the loft floor was designed together and lifted in on the same day — one crane hire, one scaffold, one building-control file.
See the Bohun Grove project · All projects
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ANDERSON · FOUNDER, LCCL CONSTRUCTION
Anderson's advice: start the party wall process the week you sign
Most clients underestimate the party wall timeline — on a semi-detached or terraced house it can add three months to the project if it is left until the drawings are finished. We serve the notices at design stage, not build stage, so the two-month notice period runs while the planning application is in.
Talk to the neighbours before the letter lands. A five-minute conversation over the fence, with the drawings in your hand, is the difference between a consent form back in a week and a surveyor's bill.
How LCCL runs the party wall process
Started at the survey, finished before the scaffold goes up. Included in every design and build contract.
WEEK 0
Free consultation call
We tell you on the first call whether the Act is likely to apply to your house and how many neighbours are involved.
WEEKS 1–2
Survey & check
The measured survey identifies the shared walls, the boundary and the neighbours' foundations; the sections of the Act that apply are confirmed.
WEEKS 2–4
Notices served
Notices drafted and served at cost with the drawings and structural details, at the same time as the planning or LDC submission. We visit the neighbours with you first.
WEEKS 4–12
Consent or award
Consent recorded, or surveyors appointed and the award and schedule of condition agreed — running alongside the planning decision, not after it.
BUILD
On site
The award's hours, access and protection requirements are in the programme; the neighbour's property is checked against the schedule at completion and everything goes in your handover pack.
“Everyone at LCCL Construction was skilled, trustworthy and worked to the highest standard. I am delighted with our loft conversion, it is exactly what we wanted and I highly recommend the company - they have transformed the quality of my home. Overall it…”
KashImaging · Google Reviews
“We are very pleased to have used Lccl Construction to do full house renovation and loft conversion to our edwardian terraced house. Project involved total strip out of interiors and remodelling repositioning the interior walls, electrical and plumbing…”
neil smith · Trustpilot
“We did a 3x10m single storey rear extension with LCCL recently. It was scheduled to take 12 weeks to complete but with Alex's experience and agile project management, we are ahead of schedule (finished in 10). Alex, and LCCL,is extremely knowledgeable and…”
Galichet Christophe · Google Reviews
Party wall questions we get asked most
On a semi or terrace, almost always: the new foundations are within 3 m of the neighbour's and usually deeper (Section 6), and the flank wall often sits on the boundary (Section 1). A notice goes to each affected neighbour; if they consent in writing you have your agreement, if they dissent a surveyor's award replaces it.
Notices are £300 each at cost within an LCCL contract. If the neighbour consents, that is the whole cost. If they dissent, surveyors are appointed and awards typically start from £750 per neighbour with an agreed surveyor, or £1,500–£3,000+ per neighbour with two surveyors — and the building owner pays both sides. Basements are the expensive case.
Two months' notice for works to the wall or excavation, one month for a new wall on the boundary, and the neighbour has 14 days to respond. Served at design stage, it runs alongside the planning decision and costs no time; served late, it can add three months to a semi or terrace project.
Silence for 14 days counts as dissent, and surveyors are appointed. It is not a veto — the Act exists to let the work proceed with the neighbour's property protected — but it does mean an award and fees. Talking to the neighbour before the letter arrives is the best way to avoid it.
No. The Party Wall Act regulates how the work is done — hours, access, protection, making good — not whether it is done. Planning is where a neighbour can object to the principle; the party wall process only governs the shared structure and the excavation.
On a semi or terrace, yes — the new floor steels bear on the party wall and the dormer is built against it (Section 2, two months' notice). Semi-detached hip-to-gable and rear dormer combinations almost always fall under permitted development, but neighbours often object informally, so we talk to them with the drawings first.
A record — photographs and notes — of the state of the neighbour's property before work starts, so that any later claim of damage can be checked against it. A surveyor prepares one as part of an award; we offer one even when the neighbour consents, because it protects both of you.
No — three separate consents from three parties: the council, building control and your neighbour. A project needs all that apply, and the party wall process is the only one with a fixed notice period. We run all three from the same drawings at the same time.
Where we run the party wall process
From Finchley N3 we cover North London, North-West London, Central London, South-West and West London, and Hertfordshire — and we also work across the rest of London, Buckinghamshire, Surrey, Kent and Essex. Every terrace and semi we work on — most of North, North-West and Central London — goes through it.