Buying commercial property is one of the most significant financial decisions you'll ever make. Get it right and you could build lasting wealth. Get it wrong and you could face years of costly problems. Here is the complete surveying and due diligence checklist — written by our founder, who has guided hundreds of buyers through the process.
Introduction: Why Due Diligence Is Everything in Commercial Property
I've been surveying commercial properties for over 25 years, and I've seen buyers make every possible mistake. Some have paid too much for buildings that looked great on the surface but were riddled with defects. Some have completed on properties with outstanding planning enforcement notices they didn't know about. Some have inherited contaminated land liability worth more than the property itself.
In almost every case, the problem was the same: insufficient due diligence before exchange.
Commercial property due diligence is a team effort — involving solicitors, surveyors, environmental consultants and sometimes structural engineers. This checklist focuses on the surveying and physical building due diligence that every buyer should complete before committing. Print it out. Tick every box. Don't skip anything.
Step 1: Commission a Full Commercial Building Survey
This is non-negotiable. A commercial building survey — also called a full structural survey — is the most important document you will get as a commercial property buyer. It tells you:
- The actual structural condition of the building
- All significant defects, from roof to foundations
- Approximate cost of remediation works
- Compliance issues you will be inheriting
- The likely maintenance requirements over the next 5–10 years
Do not rely on the vendor's information pack. Do not rely on a mortgage lender's valuation. Do not rely on a brief inspection by your solicitor. Commission your own independent survey from a commercial building surveyor.
I once surveyed a retail unit that the buyer's solicitor had visited and described as "in good order". My survey revealed significant structural cracking to the rear wall, a failing flat roof and a mains electrical installation that posed a fire risk. None of these were visible on a brief walk-round. They cost approximately £95,000 to rectify. The buyer used my report to negotiate a price reduction of £80,000 and an obligation on the vendor to replace the electrical installation before completion. The survey fee was £1,400.
Step 2: Check Planning and Building Regulations History
Before exchanging, ensure your solicitor has:
- Obtained full planning history for the property
- Checked for any outstanding enforcement notices or planning conditions
- Obtained copies of Building Regulations completion certificates for any alterations or extensions
- Verified that the current use of the building matches the planning permission (use class)
- Checked for any Article 4 directions affecting permitted development rights
Your surveyor can flag potential compliance issues during the building survey — but detailed planning due diligence sits primarily with your solicitor, potentially supported by a planning consultant for complex situations.
Step 3: Commission an Asbestos Survey
For any commercial property built or refurbished before 2000, an asbestos survey is essential. The Control of Asbestos Regulations 2012 place obligations on the duty-holder (which will become you on completion) to manage asbestos-containing materials (ACMs) in the building.
There are two types of asbestos survey:
- Management survey: A visual inspection to identify suspected ACMs that could be disturbed during normal occupation. Required for all buildings pre-2000.
- Refurbishment/demolition survey: A more intrusive survey required before any refurbishment or demolition works. Involves sampling of suspected materials.
If an asbestos register already exists, ask for a copy and have your surveyor review it. If no register exists, commission a management survey before exchange.
Step 4: Assess the Energy Performance Certificate (EPC) Rating
The Minimum Energy Efficiency Standards (MEES) regulations mean that commercial landlords cannot grant new leases or renew existing leases on properties with an EPC rating below E. From 2027, the bar is expected to rise to D, and from 2030 to C.
Before purchasing any investment property, check:
- The current EPC rating
- Whether the rating is accurate (many older EPCs were prepared on assumptions that no longer hold)
- The approximate cost of improving the rating to at least C before 2030
- Whether any current tenancy is compliant with MEES
A building with an EPC rating of F or G could be effectively unlettable until significant works are carried out. This risk must be factored into the acquisition price and investment appraisal.
Step 5: Investigate Environmental and Contamination Risk
For properties on former industrial sites, petrol stations, gas works, dry cleaners or any other potentially contaminating use, an environmental desktop study (Phase 1 Environmental Assessment) is essential — and a Phase 2 site investigation may be required.
Under the Environmental Protection Act 1990 (Part IIA), contaminated land liability can fall to the current owner if the original polluter cannot be found. In the worst cases, remediation costs can exceed the value of the land itself. This is not a risk to take lightly.
Step 6: Review Existing Tenancy Agreements and Dilapidations Exposure
If you are buying an investment property with existing tenants, you are also buying their lease obligations — including any dilapidations they may owe at lease end. Before exchanging:
- Obtain and review all current lease documents
- Assess each tenant's repairing obligations and dilapidations exposure
- Check whether any tenant has a break clause that could create a void
- Review the rent review schedule and any outstanding rent reviews
- Check whether any tenant has assigned their lease or sublet without consent
A technical due diligence report from our team will typically include an assessment of tenant dilapidations exposure, which is one of the most commercially significant findings in any investment acquisition.
Step 7: Assess Structural Condition and Investigate Any Red Flags
Your building survey will identify structural issues, but some require specialist investigation beyond the scope of a standard survey:
- Subsidence: If there is evidence of structural movement (diagonal cracking, door-frame distortion, uneven floors), a structural engineer's report may be needed
- Flat roof condition: Infrared thermography or core sampling may be needed for large flat roof areas
- Drainage: A CCTV drain survey is advisable for older properties to assess the condition of underground drainage
- Services: Electrical, gas, heating and mechanical services should be assessed by specialist engineers for older or larger buildings
Step 8: Check for Listed Building or Conservation Area Designations
Buying a listed building or a property in a conservation area brings significant restrictions on what changes you can make. Make sure you understand:
- The listing grade (Grade I, II* or II) and what it restricts
- What Listed Building Consents have been granted for previous works
- Whether any unlawful alterations have been made (which become your liability)
- The additional maintenance cost premium of a listed building
Step 9: Verify Floor Areas
If you are paying a price based on a stated floor area, verify that floor area is accurate. Vendors sometimes quote outdated or incorrectly measured figures. A measured survey to RICS IPMS standards will give you a certified, accurate floor area — and could reveal discrepancies that affect the price you should be paying.
As noted in our measured survey guide, a 2% measurement error in a 10,000 sq ft office building at £30/sq ft represents £6,000 per year in rent — or £90,000 over a 15-year lease. The stakes are very real.
Step 10: Commission a Planned Preventative Maintenance Assessment
Before completing, ask your surveyor to provide a 5 or 10-year planned preventative maintenance assessment alongside the building survey. This gives you visibility of the maintenance liabilities you are taking on and allows you to negotiate appropriately if the building has significant deferred maintenance.
A Final Word: Don't Cut Corners
Commercial property surveys are not a luxury. They are the foundation of sound decision-making. The cost of a full due diligence process — building survey, asbestos survey, EPC assessment, environmental desktop study, measured survey and PPM assessment — typically totals less than 1% of the acquisition price. The protection it provides is immeasurable.
Every piece of due diligence you skip is a risk you are accepting in silence. In commercial property, ignorance is not a defence — it's an unpriced liability.