Most “making use” scenarios are triggered by Section 2 rights, typically where the new works connect to or rely on a party wall. A common catch-all is Section 2(2)(k):
“…to execute any other necessary works incidental to the connection of a party structure with the premises adjoining it.”
In plain English: if your new extension/loft/basement connects to the party wall (e.g., steels into it, roof abutment, enclosure of a flank), you’re using that wall instead of building your own new one. Section 11(11) then steps in to rebalance costs between neighbours.
The legal core — Section 11(11)
“Where use is subsequently made by the adjoining owner of work carried out solely at the expense of the building owner the adjoining owner shall pay a due proportion of the expenses incurred by the building owner in carrying out that work; and for this purpose he shall be taken to have incurred expenses calculated by reference to what the cost of the work would be if it were carried out at the time when that subsequent use is made.”
Key takeaways
- It applies when Owner B later uses work originally paid for solely by Owner A.
- The payment is a “due proportion” (commonly around 50% for equal use of a standard shared wall), assessed at current prices — not what it cost years ago.
- Surveyors determine the sum objectively (see “How we calculate” below).
What counts as “use” or “enclosure”?
Typical examples where Section 11(11) is likely to apply:
- Enclosing on an existing party wall for a new side/rear extension rather than building a new independent wall.
- Raising a previously raised party wall: if Owner A raised the party wall for a loft; years later Owner B raises to match or encloses against the raised portion.
- Cutting in beams/joists or forming abutments/flashings where the structural reliance is on Owner A’s earlier works.
- Using a party fence wall (garden wall) as part of a new structure.
Not usually “use”: purely decorative finishes, cabling, or minor fixtures that don’t rely on the wall structurally.
How surveyors calculate the payment
The objective is to reach a fair, current-day share of the relevant wall/work actually being used.
- Define the extent of “used” work
- Length, height, thickness, and which elements are being relied on (e.g., foundations, brickwork, copings, DPCs).
- If only part of the raised thickness/height is used, the proportion is adjusted.
- Build a current-day cost model
- Using BCIS indices, current contractor quotations, published price books, or internal cost libraries.
- Preliminaries, reasonable overheads/profit, and access costs linked to that wall are considered where appropriate.
- Exclude items not integral to the wall’s function (e.g., finishes on Owner A’s side).
- Apply a fair proportion
- 50% is common for like-for-like, equal mutual benefit.
- Proportion may move up or down where use is unequal (e.g., partial height, one owner gains more structural benefit, or the other owner previously contributed).
- Credits and adjustments
- Prior contributions already made are netted off.
- If the wall is in defect and the new user avoids costs they’d otherwise incur, that may influence apportionment (separate Section 2(2)(b) / 11(5) logic may also arise where repair is the driver).
When do you have to pay?
- Timing: Usually on or before “making use” — many Awards require payment prior to fixing into or enclosing upon the wall.
- Form: The figure and timing are set out in a Party Wall Award so it’s binding and enforceable.
- If unpaid: The benefiting works typically must not proceed until payment is made; late payment can accrue interest, and the Award can be enforced.
Worked mini-examples
- Rear extension enclosing on neighbour’s previously built party wall:
Current rebuild cost for the relevant wall section (foundation + brickwork + DPC + copings) = £8,000 → 50% = £4,000 enclosure payment. - Loft party wall raise:
Owner A raised 225 mm party wall by 1.2 m five years ago. Owner B now raises their roof and encloses for 1.2 m. Current cost model for that raised portion only = £3,600 → 50% = £1,800. - Partial use (half-height/shorter run):
Calculate only the portion actually used, then apply proportion (50% or adjusted).
Common pitfalls (and how to avoid them)
- Using historic invoices
Section 11(11) requires current cost, not what it cost in 2009. - Assuming it’s always 50%
It’s a due proportion, not a fixed tariff. Unequal use ≠ equal share. - Paying for finishes
The payment covers the wall as a structure (and associated essentials). Decorative finishes and non-structural items are usually out. - Proceeding without an Award
Get the figure, timing, and method of payment into the Award to avoid site-stopping arguments.
Practical workflow
- Serve/receive valid notices for the works that connect to the party wall (usually under Section 2).
- Appoint surveyor(s) (agreed or two-surveyor route).
- Costing & proportion agreed by the surveyor(s).
- Award records: the sum, due date (often before fixing/enclosing), and any security if appropriate.
- Pay — and proceed with clarity and legal protection.
Get Your Enclosure Cost Right First Time
Simple Survey (RICS) — Nationwide • Fixed Fees • Plain English
Email team@simplesurvey.co.uk with your drawings and a brief of the proposed connection. We’ll confirm notice strategy, calculate a fair Section 11(11) figure, and draft a clear, enforceable Award.
Simple Survey — Fixed Nationwide Costs (Guide)
| Service | What you get | Fixed Fee (incl. VAT) |
|---|---|---|
| Party Wall Notice (per Adjoining Owner) | Drafting, validity check, service & tracking | £25 |
| Agreed Surveyor Award | One impartial surveyor acting for both owners | £300 |
| Building Owner’s Surveyor Award | Acting as Building Owner’s Surveyor in a two-surveyor setup | £300 |
| Section 11(11) Enclosure Calculation | Current-day cost model, due-proportion advice, Award wording | £150 |
| Complex Engineering Input | Only if necessary/proportionate | Not Simple Survey Costs |
Our fees are always fixed. We’re nationwide. We’re both experienced and RICS-qualified.
FAQ — Section 11(11) “Making Use” Costs
Q1: Is it always 50%?
No. 50% is common for equal structural benefit. Surveyors can adjust for partial use, differing thickness/height, or previous contributions.
Q2: Do I pay what my neighbour originally spent?
No. The Act requires the sum be based on what it would cost today to do the same work.
Q3: What exactly is included in the cost?
Usually: foundations, walling (including DPC/cappings), and reasonable prelims/OP linked to that wall. Finishes and unrelated items are normally excluded. VAT depends on reclaim status and is stated in the Award.
Q4: Can I refuse to pay and still build?
If an Award requires payment before making use, you risk breach of Award (and enforcement) by proceeding without paying.
Q5: Is this the same as paying for access?
No. Access is governed by Section 8 and set out in the Award; enclosure is a separate Section 11(11) cost for using the wall.
Q6: Does this apply to garden party fence walls?
Yes—if you make use of a party fence wall structurally, an enclosure share can apply.
Q7: We already paid something years ago—does that count?
Yes. The surveyors will credit prior contributions or adjust the “due proportion” accordingly.
Ready to proceed with certainty?
Email team@simplesurvey.co.uk and we’ll map your notice route, calculate a fair enclosure share, and capture it in a clean, enforceable Award.