Buying a commercial property, whether as an investment or for owner occupation, always requires careful legal due diligence. The process is designed to uncover risks that could affect value, future use, or your ability to dispose of the property at a later date. Yet despite the checks most buyers expect, there are areas that are frequently overlooked.
At Ison Harrison, we regularly act for commercial landlords, developers and business owners across England and Wales and we see the same issues arise time and again; which can lead to unnecessary cost or delay if not identified early.
Below are the points most commonly missed during commercial property due diligence and why they matter.
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Unregistered Rights That Do Not Appear on Title Documents
Land Registry title documents rarely tell the whole story. Some rights bind the land even if they are not recorded anywhere.
Common examples include:
- Informal rights of way used by neighbouring occupiers “as of right”
- Ancient drainage or utility routes not recorded on modern plans
- Long‑standing parking arrangements granted verbally to adjacent owners
These rights can restrict redevelopment or lead to disputes after completion. Site inspections and enquiries of the seller are essential, and where access or services benefit third parties, they must be dealt with contractually.
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Undisclosed Restrictions in Old Conveyances
Commercial titles often contain decades of historic deeds, particularly for older industrial units or converted mill buildings. Restrictions that regularly surface include:
- Ban on “noxious, noisy or offensive trades”
- Prohibition on building beyond a certain footprint
- Covenants requiring consent from historic landowners who no longer have a practical interest
These covenants can derail change-of-use plans or prevent intensification of use.
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Overage and Clawback Provisions
A surprisingly high number of buyers overlook overage obligations (i.e. the seller is entitled to additional payments) buried in the title or sale contract. A common overage may require a property owner pay an additional sum to a previous owner if planning permission is granted or if the land increases in value.
Buyers must therefore understand:
- How long the overage lasts
- What events trigger payment
- Whether lenders will accept the arrangement
- How the obligation is secured
If a buyer fails to address these points it can compromise development finance or make the site commercially unviable.
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Errors or Gaps in Commercial Lease Information
Where a purchase is being made as an investment, the value of the transaction is tied to the strength of the tenancies. Commonly missed issues include:
- Side letters granting rent concessions not reflected in the registered lease
- Break clauses that are easier to exercise than the headline lease suggests
- Unauthorised alterations made by tenants, risking insurance or planning breaches
- Service charge arrears or disputes that may pass to the buyer
It is essential to carry out a full lease audit to avoid any unpleasant surprises.
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Planning History That Is More Complex Than It Appears
Not all planning permissions are straightforward. Risks commonly missed include:
- Conditions requiring ongoing compliance (e.g. noise limits, operating hours, landscaping)
- Historic breaches that leave the use vulnerable to enforcement
A planning search may need to be more in depth than simply asking whether permission exists. Buyers may need to obtain specialist planning advice from a planning consultant, especially if there has been a recent change of use, or a change of use is planned.
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Building Safety and Regulatory Issues
In recent years, building safety compliance has become one of the most significant risks in commercial property transactions. Buyers often overlook:
- External wall system risks on mixed‑use buildings
- Asbestos management responsibilities
- Fire risk assessment deficiencies
- EPC compliance requirements
A property that appears sound can carry substantial obligations for ongoing remediation or regulatory work.
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Environmental Liabilities and Ground Conditions
Environmental liability is the responsibility of the landowner, even if contamination predates their ownership. Missed issues often include:
- Historic contamination from former industrial uses
- Japanese knotweed or other invasive species
- Flood risk assessments that contradict seller information
- Unregistered underground tanks
Environmental searches are only the starting point and further follow-up specialist reports may be necessary to assess actual risk.
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Accessibility, Maintenance and Practical Constraints
Not every risk is strictly legal. Practical matters frequently surface after completion, such as:
- Shared accessways with unclear maintenance responsibility
- Boundary structures in disrepair
- Hidden costs such as private road contributions or estate service charges
Identifying these early helps buyers’ budget correctly and plan for management obligations.
Why Thorough Due Diligence Matters
When you’re buying or investing in property, it’s important to go in with your eyes open. Carrying out proper due diligence helps uncover any potential issues early on, so you can make informed decisions and avoid unexpected problems further down the line. When issues are missed they can lead to:
- Delays in planned occupation or development
- Unexpected financial liabilities
- Difficulty securing lender approval
- Disputes with neighbours or tenants
- Reduced asset value
Carrying out comprehensive due diligence protects investment, reduces risk and gives buyers confidence when committing to a transaction.
How Ison Harrison Can Help
Our Commercial Property team provides clear, practical advice tailored to developers, landlords, investors, and SMEs. We offer a range of services such as:
- Conducting thorough title and lease reviews
- Highlighting risks early and offering solutions
- Working closely with planning, environmental and tax specialists where required
- Supporting negotiations to secure favourable contractual protections
- Offering a no‑obligation initial discussion for prospective buyers
If you are considering purchasing commercial property or want an expert review of a proposed transaction, our team at Ison Harrison is here to help. Contact us today for practical, commercially minded advice. Call us on 0113 284 5000 or email commprop@isonharrison.co.uk.
