Purchasing a property is one of the biggest financial decisions most people will ever make. Yet many buyers assume that once a solicitor is instructed, every potential issue with the property will automatically be identified and resolved.
In reality, solicitors do not inspect the property in person, and several critical issues can slip through the cracks—particularly when it comes to extensions, alterations, and building regulations compliance.
As mortgage brokers, we often support clients through their entire homebuying journey. While our advice is limited to mortgage products and suitability, we frequently spot red flags in property details or survey reports that require further investigation. And extensions are one of the most common blind spots.
Why Extensions Are a High-Risk Area
When a property has been extended—whether that’s a single-storey kitchen extension, a loft conversion, or a side return—several layers of compliance may be required:
✔ Planning Permission
Depending on size, height, location, and proximity to boundaries, formal planning approval may be required.
✔ Building Regulations Approval
Even if the extension doesn’t need planning permission, aspects like structural integrity, drainage, electrics, insulation, fire safety, and gas installations must comply with building regulations.
✔ Completion Certificates
Proper sign-off is essential for legal compliance, mortgageability, and future resale value.
✔ Insurance-backed warranties
If the work was recent, warranties may be needed to protect the buyer.
Yet these issues are often missed, because:
- Solicitors work from documents—not physical inspections.
If something isn’t disclosed on the Property Information Form, solicitors often have no reason to probe further. - Surveyors may not flag the need to verify permissions.
Many surveys are purely observational and will only suggest further investigations if something is visibly concerning. - Lenders increasingly rely on remote valuations.
Automated or desktop valuations are blind to completions, quality of finish, or unauthorised works.
A Real Example: How an Unchecked Extension Nearly Cost a Client Thousands
We recently supported a client purchasing a property that had undergone an extension. The lender instructed a remote valuation, meaning no one physically inspected the property on the lender’s behalf.
On reviewing the sales particulars ourselves, several elements of the extension looked questionable—particularly features that did not appear compliant with building regulations.
This prompted us to:
- Flag the issue to the client
- Recommend further investigation
- Query the situation with the solicitor
After digging deeper, it became clear:
❗ The extension did require planning permission
❗ No planning permission had ever been applied for
❗ Building regulations sign-off was missing
❗ A new gas boiler had been installed without proper certification
None of this had been highlighted by the solicitor, as the vendor had not volunteered the information—and no trigger within the lender or surveyor process prompted further checks.
Had the client completed the purchase without this being uncovered, they would have inherited a property:
- with unauthorised building work
- with potential structural or safety issues
- that might be difficult to remortgage or sell
- that could require expensive remedial work
- that could expose them to enforcement action
This is exactly the kind of situation buyers mistakenly assume “the solicitor will catch”.
Why Buyers Need to Be Proactive
Your solicitor will check legal documents, title, and searches—but they are not responsible for assessing the physical property.
This means buyers should always:
🔍 Ask direct questions about extensions and alterations
Has anything been added, altered, or converted?
🔍 Compare the floorplan with historic photos or planning records
Local council planning portals are publicly accessible.
🔍 Review the survey carefully
If anything looks recently completed or structurally unusual, investigate further.
🔍 Don’t assume “lender approval” means “all clear”
Mortgage lenders assess risk—not legal compliance.
What We Do as Brokers
While our regulatory scope is focused on mortgage product suitability, our role extends far beyond sourcing a loan.
We stay involved during the entire buying journey to:
- Review property details for anything unusual
- Spot red flags that could affect mortgageability or long-term financial risk
- Signpost clients to their solicitor or specialist surveyors when further checks are needed
- Help ensure the transaction proceeds smoothly and safely
We cannot give legal or structural advice—but we can help protect clients by making sure nothing important gets overlooked.
Conclusion
Buying a property with an extension requires careful scrutiny. Solicitors, surveyors and lenders all play important roles—but none of them physically inspect the property in a way that guarantees unauthorised works will be uncovered.
Taking a proactive, informed approach—and working with a broker who pays close attention to the details—can save buyers from costly surprises and help ensure the home they purchase is safe, compliant and mortgageable in the long term.