The Party Wall Surveyor Decision That Could Save (or Cost) You Thousands
When you serve a party wall notice to your neighbour, their response triggers one of the most important decisions in the entire party wall process: Will you proceed with one “Agreed Surveyor” acting for both parties, or will each party appoint their own surveyor?
Quick Answer: You can choose either one Agreed Surveyor (who acts impartially for both building owner and adjoining owner) or two separate surveyors (one representing each party’s interests). An Agreed Surveyor is typically cheaper (£800-£1,400 vs £1,500-£2,800 for two surveyors) and faster, but provides less independent protection for the adjoining owner. For major structural work, most parties prefer separate surveyors despite higher costs. For straightforward projects with cooperative neighbours, an Agreed Surveyor works well.
This comprehensive guide explains exactly when each option makes sense, the cost differences, legal implications, and how to decide which approach protects your interests while maintaining good neighbour relations.
Understanding Your Surveyor Options Under the Act
The Three Appointment Scenarios
When your neighbour receives your party wall notice, they have 14 days to respond with one of three options:
Option 1: Consent to the Works
- Neighbour agrees in writing to your proposed work
- No surveyors needed (theoretically)
- Rare in practice – most surveyors advise against this
- Risk: No Schedule of Condition = no protection if damage occurs
- Even with consent, many building owners still appoint surveyors for protection
Option 2: Dissent or No Response → Appoint Two Surveyors
- Neighbour formally disagrees OR doesn’t respond within 14 days
- Each party appoints their own surveyor
- Two surveyors work together to prepare the Party Wall Award
- Building owner pays both surveyors’ fees
- Most common scenario in London (70-80% of cases)
Option 3: Agree to Use One “Agreed Surveyor”
- Both parties agree to appoint a single surveyor
- Agreed Surveyor acts impartially for both building owner and adjoining owner
- Must act fairly and not favor either party
- Single fee paid by building owner
- About 20-30% of cases in London
What Is an Agreed Surveyor?
The Legal Definition
Under Section 10(1)(a) of the Party Wall etc. Act 1996:
If a building owner serves a notice…and the adjoining owner consents to it…the matter is not to be taken as being in dispute…unless one or both of the parties requests that a surveyor be appointed.
And under Section 10(1)(b):
Where a matter is in dispute…the dispute shall be determined by a single surveyor agreed upon by the building owner and the adjoining owner or by two surveyors appointed by the two parties…
What This Means:
- An Agreed Surveyor is a single RICS-qualified surveyor appointed by mutual agreement
- They must act impartially and fairly to both parties
- They have the same powers and duties as two surveyors acting together
- They prepare the Party Wall Award just like two surveyors would
- Both parties must genuinely agree to the appointment
The Agreed Surveyor’s Dual Duty
An Agreed Surveyor occupies a unique position:
Duties to Building Owner:
- Ensure work can proceed legally under the Act
- Design practical solutions that allow project completion
- Keep costs reasonable and timelines achievable
- Protect against frivolous objections from adjoining owner
Duties to Adjoining Owner:
- Protect their property from damage
- Ensure adequate Schedule of Condition
- Specify appropriate working methods and safeguards
- Award fair compensation if damage occurs
- Preserve their legal rights
The Balancing Act: The Agreed Surveyor must maintain perfect impartiality. If they favor either party, they breach their professional duty and the award could be challenged.
Example: Agreed Surveyor Impartiality
An Agreed Surveyor is inspecting for a Schedule of Condition. The adjoining owner points out a hairline crack and says “this is clearly new damage from next door’s excavations that started last month.”
If acting as two separate surveyors:
- Building owner’s surveyor would investigate and likely defend building owner
- Adjoining owner’s surveyor would document and advocate for neighbour
As Agreed Surveyor:
- Must investigate objectively
- Check planning records, photos, weather conditions
- Make impartial determination based on evidence
- Cannot automatically favor either party
This is why many adjoining owners prefer their own surveyor—they get dedicated advocacy rather than shared impartiality.
Cost Comparison: One Surveyor vs Two
Typical Fee Structures
One Agreed Surveyor:
| Project Type | Agreed Surveyor Fee | Who Pays |
|---|---|---|
| Simple chimney breast removal | £700-£1,000 | Building owner |
| Standard loft conversion | £900-£1,400 | Building owner |
| Rear extension | £1,000-£1,500 | Building owner |
| Side return extension | £900-£1,300 | Building owner |
| Basement extension | £1,800-£2,800 | Building owner |
Two Separate Surveyors:
| Project Type | Building Owner’s Surveyor | Adjoining Owner’s Surveyor | Total | Who Pays |
|---|---|---|---|---|
| Simple chimney breast removal | £600-£800 | £500-£700 | £1,100-£1,500 | Building owner (both) |
| Standard loft conversion | £800-£1,200 | £700-£1,000 | £1,500-£2,200 | Building owner (both) |
| Rear extension | £900-£1,300 | £750-£1,100 | £1,650-£2,400 | Building owner (both) |
| Side return extension | £800-£1,200 | £700-£1,000 | £1,500-£2,200 | Building owner (both) |
| Basement extension | £2,000-£3,500 | £1,500-£2,500 | £3,500-£6,000 | Building owner (both) |
Typical Savings with Agreed Surveyor: £400-£800 (20-30% cheaper)
Why Two Surveyors Costs More
You might wonder: “If one surveyor can do the job, why does having two cost almost double?”
The answer:
Separate Preparation Work:
- Each surveyor inspects independently
- Each prepares their own Schedule of Condition
- Each reviews structural drawings separately
- Each communicates with their own client
Negotiation Time:
- Two surveyors must discuss and agree on award terms
- Different professional opinions must be reconciled
- More back-and-forth correspondence
- Meetings between surveyors required
Dual Client Service:
- Building owner’s surveyor answers building owner’s questions
- Adjoining owner’s surveyor answers adjoining owner’s questions
- Separate advice given to each party
- Individual client relationship management
Professional Liability:
- Each surveyor carries separate insurance risk
- Each must defend their professional opinion
- Independent quality assurance
However: Two surveyors typically complete work more efficiently than one person trying to balance both roles, and many adjoining owners feel the extra cost is worth the independent representation.
Advantages and Disadvantages: Agreed Surveyor
✅ Advantages of Using an Agreed Surveyor
1. Lower Total Cost (20-30% Savings)
Sarah in Wandsworth faced party wall fees for her loft conversion:
- Two surveyor quote: £1,900 total (£1,100 + £800)
- Agreed surveyor quote: £1,300 total
- Savings: £600
For homeowners on tight budgets, this matters.
2. Faster Process
Typical Timeline Comparison:
| Stage | Two Surveyors | Agreed Surveyor |
|---|---|---|
| Surveyor appointment | 5-7 days | 2-3 days |
| Schedule of Condition | 10-14 days | 7-10 days |
| Award preparation | 14-21 days | 10-14 days |
| Communication/coordination | 7-10 days | 2-3 days |
| Total | 36-52 days | 21-30 days |
Time savings: 2-3 weeks
When your contractor is booked and ready to start, this matters significantly.
3. Simpler Communication
With two surveyors:
- Building owner talks to their surveyor
- Adjoining owner talks to their surveyor
- Surveyors communicate with each other
- Information passes through multiple people
- Potential for miscommunication or delays
With agreed surveyor:
- One person coordinates everything
- Direct communication with both parties
- No “telephone game” effect
- Faster decisions and clarifications
4. Reduced Potential for Disagreement
Two surveyors might disagree on:
- Whether certain pre-existing damage is significant
- Appropriate working methods
- Interpretation of structural drawings
- Compensation amounts if damage occurs
When surveyors disagree, they must:
- Hold meetings to discuss
- Exchange detailed written opinions
- Potentially refer to Third Surveyor (another £800-£1,500)
An Agreed Surveyor eliminates this conflict—one person makes determinations.
5. Better for Simple, Straightforward Projects
Example: Chimney Breast Removal in Putney
Tom in Putney was removing a ground-floor chimney breast. The work was:
- Straightforward structural engineering
- Clear scope of work
- Cooperative neighbour relationship
- Low-risk project
Agreed Surveyor made sense:
- Simple Schedule of Condition (£850 fee)
- Award prepared quickly (3 weeks)
- No complications
- Both parties satisfied
- Neighbour appreciated cost-consciousness
For projects like this, two surveyors would be overkill.
❌ Disadvantages of Using an Agreed Surveyor
1. Less Independent Advocacy for Adjoining Owner
This is the biggest concern for neighbours.
Example: Clapham Extension Dispute
Emma in Clapham was the adjoining owner. Her neighbour was building a large basement extension using an Agreed Surveyor.
Emma’s concerns:
- “Will the Agreed Surveyor really fight for my interests?”
- “The building owner is paying—won’t the surveyor favor them?”
- “I want someone who’s 100% on my side”
Even though Agreed Surveyors must be impartial, perception of bias is a real issue.
Emma appointed her own surveyor (her legal right) despite neighbour’s preference for Agreed Surveyor. This immediately converted to two-surveyor scenario.
2. Potential Conflict of Interest Perception
The uncomfortable truth:
- Building owner pays the Agreed Surveyor’s fee
- Agreed Surveyor knows who’s paying them
- Human psychology: harder to be truly impartial to payer
Most RICS surveyors maintain professional standards, but the perception issue remains.
Example: Islington Perceived Bias
An Agreed Surveyor conducting Schedule of Condition noticed a crack in the adjoining owner’s wall. The adjoining owner said “this is clearly structural and concerning.”
The Agreed Surveyor noted it as “minor cosmetic hairline crack, non-structural.”
The adjoining owner felt:
- Surveyor minimized damage to protect building owner
- Description downplayed legitimate concerns
- Would have preferred independent surveyor’s assessment
Was the Agreed Surveyor biased? Possibly not—might have been accurate assessment.
Did it feel biased to adjoining owner? Absolutely.
This perception problem alone drives many to request separate surveyors.
3. No Second Opinion on Technical Matters
With two surveyors:
- Two professionals review structural plans
- Two sets of eyes on Schedule of Condition
- Two opinions on appropriate safeguards
- Higher likelihood of catching problems
With Agreed Surveyor:
- Single professional judgment
- No peer review
- Mistakes less likely to be caught
Example: Richmond Structural Oversight
An Agreed Surveyor approved a party wall award for a loft conversion. The structural engineer’s drawings showed steel beams bearing 150mm into the party wall.
The Agreed Surveyor missed:
- Beam bearing was excessive for wall thickness
- Could cause cracking or deflection
- Should have specified additional support
Problem emerged during construction:
- Cracks appeared in neighbour’s wall
- Retrospective reinforcement required: £2,800
- Neighbour blamed Agreed Surveyor for not catching issue
If two surveyors had reviewed:
- Adjoining owner’s surveyor likely would have flagged concern
- Discussion would have caught issue pre-construction
- Award would have specified proper safeguards
4. Limited Recourse if Adjoining Owner Unhappy
With your own surveyor:
- You can give detailed instructions
- Request specific protections
- Challenge draft award terms before finalization
- Surveyor advocates for changes you want
With Agreed Surveyor:
- You must accept their impartial determinations
- Can’t instruct them to favor your position
- Limited ability to request changes
- If unhappy, your only option is appointing own surveyor (resetting entire process)
5. May Not Be Appropriate for Complex Projects
High-risk projects where two surveyors are better:
✅ Basement excavations:
- Significant structural risk
- Expensive potential damage
- Complex engineering
- High adjoining owner concern
✅ Major structural alterations:
- Party wall being significantly modified
- Multiple party walls affected
- Large-scale projects
✅ Projects with difficult relationships:
- Previous disputes between neighbours
- Lack of trust
- History of disagreements
✅ High-value properties:
- When properties worth £1M+
- Damage claims potentially large
- Worth paying extra for independent representation
Advantages and Disadvantages: Two Separate Surveyors
✅ Advantages of Using Two Surveyors
1. Independent Representation and Advocacy
This is the primary reason most London parties choose two surveyors.
Building Owner’s Surveyor:
- Actively advocates for project feasibility
- Designs practical solutions to challenges
- Minimizes unnecessary restrictions
- Challenges unreasonable adjoining owner demands
- Protects building owner from excessive costs
Adjoining Owner’s Surveyor:
- Actively protects neighbour’s property
- Identifies all potential risks
- Ensures comprehensive Schedule of Condition
- Advocates for strong safeguards
- Fights for fair compensation if damage occurs
Example: Hampstead Basement Protection
David in Hampstead was the adjoining owner to a major basement excavation. His surveyor:
Identified issues Agreed Surveyor might miss:
- Requested monitoring equipment on David’s walls (£800 value)
- Specified underpinning depth greater than building owner suggested
- Required specialist insurance beyond standard coverage
- Demanded weekly progress reports
- Negotiated £5,000 security deposit for potential damage
David’s surveyor’s fee: £1,500
Value of protections obtained: Estimated £15,000-£20,000 if issues arose
David’s assessment: “Money well spent for peace of mind”
2. Checks and Balances
Two professionals reviewing the same work provides quality assurance.
Peer Review Benefits:
- Structural drawings reviewed by two qualified people
- Schedule of Condition validated by second opinion
- Award terms negotiated and refined
- Professional standards maintained through mutual oversight
Example: Chelsea Structural Catch
Building owner’s surveyor approved a loft conversion with steel beams bearing 120mm into party wall.
Adjoining owner’s surveyor reviewed and said: “Wait—the wall is only 9 inches (225mm) thick. 120mm bearing leaves only 105mm remaining wall thickness, which is below minimum safe bearing.”
Result:
- Building owner redesigned support system
- Padstones added to distribute loads
- Party wall protected from over-stress
- Avoided potential structural failure
Two surveyors caught a problem one might miss.
3. Better for Contentious or High-Stakes Projects
When you definitely want two surveyors:
High-value properties (£1M+):
- Potential damage claims are large
- Extra surveyor cost (£700-£1,000) is proportionally tiny
- Risk management justifies independent representation
Complex structural work:
- Basements
- Major extensions
- Underpinning
- Structural alterations to party walls
Difficult relationships:
- Previous disputes with neighbour
- Lack of trust or communication
- Known litigious neighbour
- Commercial properties (different interests)
Example: Kensington Basement £2.5M Properties
Adjacent properties each worth £2.5M. Building owner excavating 3-metre-deep basement.
Risk assessment:
- Potential damage to £2.5M property
- If major structural issues: £100,000+ repairs possible
- Extra surveyor cost: £1,200
Decision: Both parties insisted on separate surveyors
Outcome:
- Comprehensive protection for both sides
- Detailed monitoring throughout work
- No disputes or damage
- £1,200 extra cost = insurance policy on £2.5M asset
Proportionality: When property values are high, penny-pinching on surveyors is false economy.
4. Clear Lines of Communication and Instruction
With your own surveyor:
- Direct relationship
- Can ask questions freely
- Give specific instructions
- Receive dedicated advice for your situation
- Surveyor’s loyalty is clear
Example: Wimbledon Adjoining Owner Questions
Margaret in Wimbledon (adjoining owner) had many questions during her neighbour’s extension:
- “Is this vibration normal?”
- “Should there be this much dust?”
- “Can they really work until 6pm?”
- “What if I notice a new crack?”
Her surveyor:
- Answered all questions promptly
- Visited site when Margaret concerned
- Advocated for Margaret’s comfort and rights
- Provided reassurance and professional opinion
Value: Peace of mind throughout 12-week project
An Agreed Surveyor handling both parties might struggle to provide this level of individual attention.
5. Professional Insurance and Liability Protection
With separate surveyors:
- Each surveyor carries Professional Indemnity Insurance
- Clear lines of responsibility
- If surveyor makes error, insurance covers damages
- Both building owner and adjoining owner protected
With Agreed Surveyor:
- Single surveyor’s insurance covers both parties
- But if impartiality questioned, insurance claims complex
- Potential conflict in who’s protected if dispute arises
❌ Disadvantages of Using Two Surveyors
1. Higher Cost (20-30% More Expensive)
The math:
- Agreed Surveyor: £1,200
- Two Surveyors: £1,800 (£1,000 + £800)
- Extra cost: £600
For some homeowners, particularly on tight budgets, this matters significantly.
2. Longer Timeline
Additional time required:
- Appointing second surveyor: 3-5 days
- Coordinating schedules between two professionals: 3-7 days
- Surveyors negotiating award terms: 5-10 days
- Total extra time: 2-3 weeks
When your contractor is booked and charging standing time, delays cost money.
3. Potential for Disagreement Between Surveyors
If surveyors disagree significantly, they must:
- Hold meetings to discuss (billable time)
- Exchange detailed professional opinions (more time)
- Potentially appoint Third Surveyor (another £800-£1,500)
Example: Streatham Surveyor Disagreement
Two surveyors disagreed on whether pre-existing crack was structural or cosmetic.
Building owner’s surveyor: “Superficial plaster crack, no significance” Adjoining owner’s surveyor: “Potential structural movement, requires monitoring”
They couldn’t agree, so appointed Third Surveyor:
- Third Surveyor fee: £1,200
- Additional delay: 3 weeks
- Third Surveyor agreed with adjoining owner’s surveyor
Total cost: £3,100 (vs. £1,300 for Agreed Surveyor)
But: Adjoining owner’s property WAS properly protected, so extra cost justified.
4. More Complex Communication
Communication chain:
- Building owner → Building owner’s surveyor
- Building owner’s surveyor → Adjoining owner’s surveyor
- Adjoining owner’s surveyor → Adjoining owner
- And back again
Potential for:
- Information getting lost or distorted
- Delays in responses
- Misunderstandings between surveyors
- Coordination challenges
Decision Framework: Which Option Should You Choose?
When an Agreed Surveyor Makes Sense
✅ Choose ONE Agreed Surveyor if:
Project Characteristics:
- ✅ Simple, straightforward work (chimney removal, minor alterations)
- ✅ Low structural risk
- ✅ Small-scale projects
- ✅ Budget-conscious projects where every £500 matters
- ✅ Time-sensitive projects (contractor booked soon)
Relationship Factors:
- ✅ Good relationship with neighbour
- ✅ Trust exists between parties
- ✅ Both parties want to minimize costs
- ✅ Neighbour is reasonable and cooperative
- ✅ No history of disputes
Practical Considerations:
- ✅ Property values relatively modest (under £750k)
- ✅ Both parties inexperienced with party wall matters (want simplicity)
- ✅ Neighbour explicitly agrees to Agreed Surveyor
- ✅ Building owner willing to accept impartial professional judgment
Example Perfect Scenario for Agreed Surveyor:
Tom and Sarah live in semi-detached houses in Bromley, each worth £450k. Tom wants to remove his ground-floor chimney breast. Sarah is his friend of 10 years. Work is straightforward structural alteration.
Decision: Agreed Surveyor
- Simple work, low risk
- Friendly relationship
- Budget matters to both
- Quick timeline desired
- Result: £900 total cost, 3-week process, everyone happy
When Two Surveyors Are Better
✅ Choose TWO Separate Surveyors if:
Project Characteristics:
- ✅ Complex structural work (basements, major extensions, underpinning)
- ✅ High risk of damage or complications
- ✅ Large-scale or expensive projects
- ✅ Work affecting multiple party walls
- ✅ Novel or unusual construction methods
Relationship Factors:
- ✅ No relationship or poor relationship with neighbour
- ✅ Previous disputes or disagreements
- ✅ Lack of trust
- ✅ Neighbour concerned or anxious about work
- ✅ Commercial property involved (different interests than residential)
Practical Considerations:
- ✅ High property values (£1M+)
- ✅ Adjoining owner wants independent representation
- ✅ Either party feels strongly about having dedicated advocate
- ✅ Legal advice recommends separate surveyors
- ✅ Insurance requirements suggest independent review
Example Perfect Scenario for Two Surveyors:
David in Kensington (£2.2M property) planning major basement excavation going 3.5 metres deep. Neighbour Emma (£2.3M property) concerned about structural risk to her Victorian house. No prior relationship between parties.
Decision: Two Surveyors
- High-risk complex work
- Expensive properties
- Neighbour anxious and wants protection
- Extra £1,200 cost is tiny relative to property values
- Result: £2,800 total cost, comprehensive protection, no disputes, peace of mind
The Adjoining Owner’s Perspective
Your Rights as Adjoining Owner
If you’re the neighbour receiving a party wall notice, you have absolute right to:
✅ Appoint your own surveyor regardless of building owner’s preference ✅ Refuse to use an Agreed Surveyor even if building owner suggests it ✅ Not pay any surveyor costs (building owner pays both) ✅ Change your mind early in process (within reason)
The building owner cannot: ❌ Force you to use an Agreed Surveyor ❌ Make you pay for surveyors ❌ Pressure you into accepting less protection
Should You Accept an Agreed Surveyor?
Questions to ask yourself:
1. How complex is the work?
- Simple chimney removal → Agreed Surveyor probably fine
- Basement excavation → Probably want your own surveyor
2. How much do you trust your neighbour?
- Good friend, track record of honesty → Agreed Surveyor might work
- Stranger or previous issues → Want your own surveyor
3. How valuable is your property?
- £400k property → Agreed Surveyor saves costs for both
- £2M property → Extra £800 for own surveyor is nothing
4. How risk-averse are you?
- Comfortable with uncertainty → Agreed Surveyor acceptable
- Want maximum protection → Get your own surveyor
5. How important is independent advice to you?
- Want to minimize hassle → Agreed Surveyor simpler
- Want dedicated advocate → Get your own surveyor
Example: Fulham Adjoining Owner Decision
Lisa in Fulham received party wall notice from neighbour doing loft conversion.
Her thought process:
- Work seems straightforward (standard loft)
- Neighbour is friendly, lived there 8 years
- Her property worth £650k (not ultra-high value)
- She’s generally not anxious person
- Agreed Surveyor would save neighbour £700
- Being good neighbour matters to her
Decision: Agreed to use Agreed Surveyor
Outcome:
- Process smooth and professional
- Schedule of Condition thorough
- Award fair to both parties
- Saved neighbour money, goodwill maintained
- Lisa satisfied with decision
Contrast: Hackney Adjoining Owner Decision
Peter in Hackney received notice for basement excavation.
His thought process:
- Basement = high-risk work
- Don’t know neighbour well (moved in 6 months ago)
- His property Victorian, foundation concerns
- He’s naturally cautious
- Own surveyor will cost neighbour £900 extra, but neighbour doing £200k project
- His peace of mind worth more than saving neighbour £900
Decision: Appointed his own surveyor
Outcome:
- His surveyor identified foundation issues requiring additional protections
- Monitoring equipment installed
- Regular inspections during work
- No damage occurred
- Peter confident his property was protected
The Building Owner’s Perspective
Can You Encourage Agreed Surveyor?
Yes, but carefully:
✅ Appropriate approaches:
- Explain cost savings benefit both parties
- Note faster timeline
- Suggest experienced, reputable Agreed Surveyor
- Emphasize RICS professional standards guarantee impartiality
- Offer to share Agreed Surveyor’s credentials
❌ Inappropriate approaches:
- Pressure or coerce neighbour
- Suggest they’re being unreasonable if they want own surveyor
- Imply they’re costing you money unfairly
- Make them feel guilty about exercising legal rights
Remember: Under the Party Wall Act, you pay for both surveyors regardless. This is the price of doing building work that affects your neighbour.
Managing Costs as Building Owner
If your neighbour appoints their own surveyor:
Accept it gracefully:
- It’s their legal right
- Shows they’re taking process seriously (good thing!)
- Two surveyors provide better checks and balances
- Cost difference (£600-£800) is small relative to total project costs
Budget appropriately:
- Always budget for two surveyors when planning project
- If you end up with Agreed Surveyor, it’s a bonus saving
- Don’t plan finances around hoped-for Agreed Surveyor scenario
Example: Wimbledon Building Owner
James planning £80,000 loft conversion in Wimbledon.
His budget:
- Building work: £80,000
- Planning fees: £1,200
- Building control: £850
- Party wall (two surveyors): £2,000 (budgeted)
- Contingency: £8,000
- Total: £92,050
His neighbour agreed to Agreed Surveyor:
- Actual party wall cost: £1,300
- Saving: £700
James’s reaction: “Great! Unexpected bonus. I’ll put it toward the contingency fund.”
This is the right mindset: Budget for higher cost, be pleasantly surprised if lower.
Practical Process: How Agreed Surveyor Appointment Works
Step-by-Step Timeline
Day 0: Notice Served
- Building owner serves party wall notice
- 14-day response period begins
Day 1-5: Building Owner Identifies Potential Agreed Surveyor
- Research RICS-qualified surveyors in area
- Check credentials, experience, reviews
- Contact surveyor to confirm availability and fees
- Get quote for Agreed Surveyor service
Day 5-7: Building Owner Proposes Agreed Surveyor to Neighbour
- Send letter or email to neighbour suggesting Agreed Surveyor
- Include surveyor’s credentials and quote
- Explain benefits (lower cost, faster process)
- Make clear it’s optional—neighbour can appoint own surveyor
Example Neighbour Communication:
Dear [Neighbour],
Thank you for considering the party wall notice I served on [date] for my planned [project description].
I wanted to propose that we use an “Agreed Surveyor” to handle the party wall matters. This means one RICS-qualified surveyor would act impartially for both of us, rather than each appointing separate surveyors.
Benefits of Agreed Surveyor approach:
- Lower total cost (around £1,200 vs £2,000 for two surveyors)
- Faster process (3-4 weeks vs 6-8 weeks)
- Single point of contact for both of us
I’ve identified [Surveyor Name], RICS, who has 15 years of party wall experience in [area]. Their credentials are attached. They’ve quoted £1,200 for the complete service, which I’ll pay as required under the Act.
This is entirely optional. You have every right to appoint your own surveyor if you prefer, and I’ll respect that decision completely. Please let me know your preference within the next few days.
Kind regards, [Your name]
Day 8-14: Neighbour Responds
If neighbour agrees:
- Both parties sign appointment letter
- Agreed Surveyor begins work immediately
- Proceed with Schedule of Condition and Award
If neighbour wants own surveyor:
- Neighbour appoints their surveyor
- Building owner appoints their surveyor
- Process continues with two surveyors
If neighbour doesn’t respond by Day 14:
- Deemed to have dissented
- Building owner can appoint surveyor on neighbour’s behalf
- Neighbour still has right to appoint own surveyor later (within reasonable time)
The Appointment Letter
Both parties must sign an Agreed Surveyor appointment letter:
Key elements:
AGREED SURVEYOR APPOINTMENT
Building Owner: [Name, Address]
Adjoining Owner: [Name, Address]
Property Affected: [Addresses]
The parties agree to appoint [Surveyor Name], RICS, of [Surveyor Address] as Agreed Surveyor under Section 10(1)(b) of the Party Wall etc. Act 1996.
The Agreed Surveyor shall:
- Prepare Schedule(s) of Condition
- Determine the Party Wall Award
- Act impartially for both parties
- Charge fees in accordance with quote dated [date]
The Building Owner agrees to pay the Agreed Surveyor's fees.
Signed:
Building Owner: _________________ Date: _______
Adjoining Owner: ________________ Date: _______
Agreed Surveyor: ________________ Date: _______
Both parties receive signed copy.
What If You Change Your Mind?
Switching from Agreed Surveyor to Two Surveyors
Can you switch? Yes, but with limitations.
Before Schedule of Condition completed:
- Relatively easy to switch
- Adjoining owner can appoint own surveyor
- Building owner appoints own surveyor
- Agreed Surveyor withdraws
- Start fresh with two surveyors
After Schedule of Condition completed:
- More complicated
- Agreed Surveyor may charge for work done
- Could delay process significantly
- May need good reason to justify switch
After Award issued:
- Very difficult to switch
- Award already legally binding
- Would need to challenge Award through Third Surveyor or court
Example: Battersea Mid-Process Switch
Emma in Battersea initially agreed to Agreed Surveyor for neighbour’s extension. After Schedule of Condition, she became uncomfortable with impartiality concerns.
She decided to appoint own surveyor:
- Paid Agreed Surveyor £450 for work completed
- Appointed her own surveyor
- Process reset with two surveyors
- Award prepared by two surveyors
- Total delay: 4 weeks
- Extra cost: £450
But: Emma felt more protected with own surveyor, worth the cost and delay to her.
Lesson: Better to decide upfront what you want rather than switching mid-process.
Third Surveyor: The Ultimate Backup
When Surveyors Can’t Agree
If two surveyors cannot agree on terms of the Award, they must appoint a Third Surveyor under Section 10(4) of the Act.
Third Surveyor’s role:
- Acts as referee between two surveyors
- Reviews both surveyors’ opinions
- Makes final binding determination
- Decision cannot be appealed (except through courts)
When Third Surveyor needed:
- Two surveyors have genuinely different professional opinions
- Cannot reach consensus after reasonable negotiation
- Technical dispute about construction methods, risk assessment, or damage evaluation
Third Surveyor costs:
- Typically £800-£1,500
- Paid by building owner
- Can be split between parties by agreement
How rare is this?
- Very rare: Less than 5% of party wall cases
- Most surveyors negotiate and reach agreement
- Professional relationships and reputation encourage compromise
Example: Notting Hill Third Surveyor Case
Two surveyors disagreed on underpinning methodology for basement excavation in Notting Hill.
Building owner’s surveyor: “Standard mass concrete underpinning sufficient” Adjoining owner’s surveyor: “Piled underpinning required due to ground conditions”
Difference in cost: £15,000
Third Surveyor appointed:
- Reviewed soil reports, structural engineering
- Inspected site conditions
- Issued determination: “Modified mass concrete with additional reinforcement”
- Compromise solution
- Third Surveyor fee: £1,200
Both surveyors accepted determination, work proceeded.
Common Questions: Agreed Surveyor vs Two Surveyors
Q: Can I use my builder’s recommended surveyor as Agreed Surveyor?
A: Technically yes, but not recommended. This creates perception of bias toward building owner. For Agreed Surveyor to be truly impartial, they should have no pre-existing relationship with either party. Adjoining owner likely to refuse and appoint own surveyor if they suspect connection.
Q: What if my neighbour agrees to Agreed Surveyor but then becomes difficult during the process?
A: The Agreed Surveyor must remain impartial. If your neighbour makes unreasonable demands, the Agreed Surveyor should professionally explain why demands can’t be accommodated. The Award will be based on professional judgment, not either party’s unreasonable wishes. If the process becomes very contentious, one party can still appoint their own surveyor (though this restarts the process).
Q: Can I save money by being my own surveyor?
A: No. The Party Wall Act requires RICS-qualified surveyors (or other appropriately qualified professionals). You cannot represent yourself in surveyor role. However, you can handle party wall notices yourself before surveyors are appointed—but once surveyors are needed, they must be qualified professionals.
Q: What happens if the Agreed Surveyor makes a mistake?
A: Agreed Surveyors carry Professional Indemnity Insurance. If they make a genuine error causing loss, either party can make claim against their insurance. However, you’d need to prove professional negligence, not just disagreement with their judgment. This is one reason some parties prefer own surveyor—clearer line of professional duty owed to them specifically.
Q: Is an Agreed Surveyor ever mandatory?
A: No. The Act allows for Agreed Surveyor OR two surveyors—it’s always a choice. Neither party can be forced to use an Agreed Surveyor. If you want your own surveyor, that’s your right.
Q: Can the building owner choose the Agreed Surveyor without my input?
A: No. “Agreed” means both parties must genuinely agree on the appointment. If the building owner just appoints someone and calls them “Agreed Surveyor” without your consent, that’s not valid. You must sign appointment letter agreeing to the specific surveyor.
Q: What’s a realistic expectation for cost savings with Agreed Surveyor?
A: Typically £400-£800 total savings (20-30% cheaper). For example:
- Two surveyors: £1,800 (£1,000 + £800)
- Agreed surveyor: £1,200
- Saving: £600
The building owner pays both scenarios, so this is their saving. Adjoining owner doesn’t pay either way.
Taking Action: Making Your Decision
Checklist for Building Owners
Before suggesting Agreed Surveyor to neighbour:
- [ ] Assess project complexity honestly
- [ ] Research qualified RICS surveyors in your area
- [ ] Get quotes from potential Agreed Surveyors
- [ ] Check surveyor credentials and experience
- [ ] Prepare professional communication to neighbour
- [ ] Include surveyor’s credentials with proposal
- [ ] Make clear it’s optional, not required
- [ ] Budget for two surveyors regardless
- [ ] Be prepared to pay for two if neighbour prefers
If neighbour agrees to Agreed Surveyor:
- [ ] Both parties sign appointment letter
- [ ] Provide Agreed Surveyor with all relevant documents
- [ ] Cooperate with Schedule of Condition access
- [ ] Trust the Agreed Surveyor’s impartial judgment
- [ ] Pay fees promptly when invoiced
If neighbour wants own surveyor:
- [ ] Accept decision gracefully
- [ ] Appoint your own surveyor
- [ ] Proceed with two-surveyor process
- [ ] Maintain good communication with neighbour
- [ ] Pay both surveyors’ fees as required
Checklist for Adjoining Owners
When deciding whether to accept Agreed Surveyor:
- [ ] Assess project complexity and risk
- [ ] Consider your relationship with building owner
- [ ] Review proposed Agreed Surveyor’s credentials
- [ ] Evaluate your property value and risk exposure
- [ ] Consider your own risk tolerance and preference
- [ ] Discuss with family/spouse if joint ownership
- [ ] Don’t feel pressured—it’s your choice
- [ ] Remember: you don’t pay either way
If accepting Agreed Surveyor:
- [ ] Review and sign appointment letter
- [ ] Keep copy for your records
- [ ] Provide access for Schedule of Condition
- [ ] Communicate concerns to Agreed Surveyor directly
- [ ] Review draft Award carefully
- [ ] Ask questions if anything unclear
If appointing own surveyor:
- [ ] Research RICS-qualified surveyors
- [ ] Interview 2-3 surveyors before choosing
- [ ] Confirm experience with similar projects
- [ ] Discuss concerns and expectations
- [ ] Sign surveyor appointment letter
- [ ] Building owner pays your surveyor’s fees
- [ ] Communicate through your surveyor primarily
Conclusion: The Right Choice for Your Situation
The decision between an Agreed Surveyor and two separate surveyors is not about right or wrong—it’s about what’s appropriate for your specific circumstances.
Key Principles to Remember:
✅ For simple, low-risk projects with cooperative neighbours: Agreed Surveyor usually makes sense—saves money and time while providing adequate protection
✅ For complex, high-risk projects or difficult relationships: Two surveyors provide stronger protection and clearer advocacy despite higher cost
✅ Building owners: Budget for two surveyors, propose Agreed Surveyor respectfully, accept neighbour’s decision gracefully
✅ Adjoining owners: Exercise your right to choose based on project complexity, your risk tolerance, and your need for independent representation
✅ Both parties: Remember the extra £600-£800 for two surveyors is small relative to property values and project costs—make decisions based on protection and peace of mind, not just cost
The Bottom Line:
Party wall matters already involve legal complexity, structural risk, and neighbour relationships. The surveyor decision should optimize for protection and professional quality, not just minimizing costs. Whether you choose one Agreed Surveyor or two separate surveyors, ensure you’re working with qualified RICS professionals who will protect your interests and facilitate a successful project outcome.
Need Help Deciding on Surveyor Approach?
Our RICS-qualified party wall surveyors can advise on whether Agreed Surveyor or two-surveyor approach makes sense for your specific project. We act as Building Owner’s Surveyor, Adjoining Owner’s Surveyor, or Agreed Surveyor depending on circumstances.
Get Expert Guidance:
Our Services:
- Building Owner representation
- Adjoining Owner representation
- Agreed Surveyor appointments
- Impartial professional advice
- Transparent fee quotes
- 15+ years London experience
Typical fees:
- Building Owner’s Surveyor: £750-£1,400
- Adjoining Owner’s Surveyor: £650-£1,200
- Agreed Surveyor: £900-£1,600
Let us help you navigate the surveyor decision with confidence.
Disclaimer: This guide provides general information about Agreed Surveyors and two-surveyor options under the Party Wall etc. Act 1996. Every project and relationship is unique. The right choice depends on your specific circumstances including project complexity, property values, neighbour relationships, and personal risk tolerance. Always consult with qualified RICS party wall surveyors for advice specific to your situation. This article does not constitute legal or professional advice.
PLANNING BUILDING WORK? DECIDE ON YOUR SURVEYOR APPROACH EARLY IN THE PARTY WALL PROCESS TO ENSURE SMOOTH TIMELINES AND APPROPRIATE PROTECTION FOR ALL PARTIES!
