Appointing one “Agreed Surveyor” (jointly by both owners) is often billed as the fastest, cheapest way to resolve a Party Wall dispute under the Party Wall etc. Act 1996. Sometimes, it absolutely is. But “one surveyor for both sides” isn’t a magic bullet—and in certain situations it can carry drawbacks you should weigh before you commit.
Below we set out the main disadvantages, when a two-surveyor route may be wiser, and how to decide what’s right for your project (and neighbour relationship).
The main drawbacks of an Agreed Surveyor
1) No built-in safety net if you disagree with their approach
With two surveyors, differences can be escalated to the Third Surveyor for a quick, expert determination. With an Agreed Surveyor, there is no Third Surveyor. Your only formal remedy is a County Court appeal within 14 days of service—slower, costlier, and higher-stakes than a technical referral.
Implication: If you anticipate points of principle will be contested (methodology, access terms, cost apportionment, security for expenses, etc.), the Agreed Surveyor route reduces your mid-process options.
2) Perception risk: one brain, two clients
Agreed Surveyors must act impartially. Most do. But one person balancing two sets of interests can feel uncomfortable—especially when money or programme pressure bites. Even where the decisions are technically sound, perceived bias can sour neighbour relations and prompt challenges.
Implication: If trust between neighbours is already thin, having separate surveyors can reduce suspicion and keep conversations constructive.
3) Complex or high-risk projects need extra bandwidth
Deep excavations, basement works, intricate interfaces with listed structures, multi-owner freehold/leasehold blocks—these files are busy. Two surveyors can divide tasks, stress-test each other’s reasoning, and move in parallel. A single surveyor may become a bottleneck, delaying agreement.
Implication: For complex programmes with tight lead-ins, the two-surveyor route can be the faster in practice.
4) Fewer checks and balances on scope and drafting
The two-surveyor system is intentionally adversarial-lite: each surveyor tests scope, drawings and terms from their owner’s perspective before anything is agreed. With one surveyor, you lose that iterative scrutiny, raising the risk of over- or under-cooking provisions, or missing nuances that another specialist would have spotted.
Implication: Where the stakes are significant (construction risk, overlapping rights, long-term maintenance duties), the extra pair of expert eyes is valuable.
5) If the Agreed Surveyor stalls, you stall
Should an Agreed Surveyor neglect to act or become incapable, the process has to restart (new appointment and fresh momentum). With two surveyors, the other can proceed ex parte in certain circumstances or seek Third Surveyor assistance to keep things moving.
Implication: The single-point-of-failure risk is real; choose your Agreed Surveyor for capacity as well as competence.
6) Communication bottleneck
All queries, clarifications and changes funnel through one person. That can be tidy—but it can also slow decision-making, especially if multiple adjoining owners, managing agents or design consultants are involved.
Implication: Where there are many stakeholders, separate surveyors can run parallel tracks and reduce lag.
When an Agreed Surveyor can still be a smart choice
- Low-complexity domestic works with clear drawings and cooperative neighbours
- Tight budgets where both owners genuinely prefer one fixed fee and a lean process
- Good relationships, where both sides are comfortable with a single, neutral expert
If you go this route, agree in writing how communications will work, confirm the scope the surveyor will cover, and make sure both owners are confident in the surveyor’s impartiality, experience and capacity.
When two surveyors are usually better
- Basements / deep excavations / piling
- Multiple adjoining owners (freeholder + several long leaseholders)
- Sensitive structures (listed, very old, visibly fragile)
- Tense neighbour relations or prior disputes
- Programmes with little float, where a single holdup would snowball
In these cases, two surveyors often reduce overall risk and time, even if the headline fee is higher.
FAQs
Is an Agreed Surveyor always cheaper?
Often—but not always. If the matter becomes contentious or complex, a second expert’s input (and the ability to refer to a Third Surveyor in the two-surveyor route) can avoid appeals and delays that dwarf any saving.
Can I switch from an Agreed Surveyor to two surveyors later?
Once appointed in writing, an Agreed Surveyor’s appointment can’t be unilaterally rescinded under the Act. If they deem themselves incapable or neglect to act, new appointments can be made, but you can’t simply “fire” them.
Do we still need to select a Third Surveyor with an Agreed Surveyor?
No. There is no Third Surveyor in the Agreed Surveyor route. Determinations rest with the Agreed Surveyor, subject only to court appeal.
What if my neighbour insists on an Agreed Surveyor and I’m uncomfortable?
You’re entitled to appoint your own surveyor. That’s precisely why the Act offers both models.
Will an Agreed Surveyor speed things up?
Sometimes. But if the project is complex or relations are strained, the single-person model can slow things down. Pick the model that fits the risk profile, not just the headline fee.
Transparent, fixed pricing
- Party Wall Notice service: £25 per adjoining ownership (multi-notice bundles discounted).
- Act administration as Agreed Surveyor (single surveyor): typically £300 fixed-fee, depending on complexity and number of notices/owners.
- Two-surveyor route (we act for the Building Owner): fixed-fee proposals from £325 for our side. (The Adjoining Owner’s surveyor often bills hourly; we work to keep those costs reasonable and contained.)
- Complex works (deep excavations, multi-owner blocks): we’ll still offer the fixed pricing as above.
- No surprises, no creeping extras. You’ll know the number before we start.
Bottom line
The Agreed Surveyor route can be the leanest way through—but it’s not universally best. If your project is complex, time-critical, or neighbour relations are fragile, the two-surveyor model with a Third Surveyor safety valve often delivers a smoother, safer outcome.
Unsure which route fits your project?
Email team@simplesurvey.co.uk for an honest, fast recommendation and a fixed-fee proposal that matches your risk, timeline and budget.