When acquiring, financing or taking over a commercial property, it is not enough to know that the building operates today. The decision requires an understanding of defects, compliance gaps, remaining service life, expected expenditure and uncertainty in the evidence. Technical due diligence brings these factors into one decision-ready report.
What is technical due diligence?
Technical due diligence (TDD) is a systematic review of a property's physical and technical condition, documentation, use and foreseeable expenditure. RICS guidance makes the purpose, property type and client's requirements central to the scope. A buyer, lender, portfolio owner and vendor therefore need different emphasis.
TDD is not a valuation, detailed design or contractor's bill of quantities. It identifies material risks, tests the available evidence, states limitations and places expenditure into a relevant time horizon.
What is reviewed?
Documentation and the data room
The review tests the presence, currency and consistency of design information, permits, occupation approvals, inspection certificates, maintenance records and repair history. A document existing in the data room does not prove that it reflects the building as it stands or is used today.
Building fabric and external areas
The inspection covers accessible structural and non-structural elements, roofs, façades, windows, finishes, waterproofing, internal accommodation and external paved areas. Defects are considered together with cause, extent, urgency and the risk of further deterioration.
Mechanical, electrical and vertical transportation systems
Heating, cooling, ventilation, electrical distribution, lighting, water, drainage, controls, lifts and relevant fire systems are reviewed for condition, capacity, maintenance, statutory inspections, parts availability and remaining life.
Actual use, permits and tenant alterations
Approved use and design records are compared with the site condition. Layout changes, tenant works and changes to fire compartments may affect lawful occupation, fire safety and future CAPEX.
Areas, leases and operating obligations
Where included, contractual and measured areas, landlord and tenant technical obligations, fit-out condition and risks to sustainable rental income are examined. Different measurement conventions can affect rent, service charges and asset value.
Energy and environmental modules
Energy consumption, efficiency, hazardous materials, waste and potential contamination may be included or commissioned as separate specialist modules, depending on the asset and the client's risk profile.
How does the process work?
- Scope: define the transaction purpose, asset type, decision questions, programme and information available.
- Desktop review: assess the data room and issue a schedule of missing or conflicting evidence.
- Inspection and diagnostics: inspect accessible areas and undertake targeted testing where risks justify it.
- Risk assessment: consider severity, likelihood, urgency, remaining life and fitness for intended use.
- Reporting: set out findings, priorities, CAPEX/OPEX implications, limitations and next actions.
For time-sensitive transactions, a 48-hour post-inspection summary can precede the final report. Potential deal-breakers should be reported immediately rather than held until the full document is complete.
What should the report deliver?
A robust report separates verified facts from professional assumptions. Each material issue should have an evidence source, impact, priority and recommendation. Expenditure is assigned to short-, medium- and long-term horizons, distinguishing immediate liabilities from planned renewal and optional improvement.
The report can support price and contract negotiations without becoming a separate pricing service. It does not set the asset value; it identifies technical liabilities and uncertainty that the buyer may otherwise inherit.
What can TDD not confirm without further investigation?
Standard TDD is predominantly visual and non-destructive. Concealed structures, inaccessible areas, pipe interiors and material properties may require opening-up, CCTV surveys, ground-penetrating radar or laboratory tests. Accessibility, confidence and recommended further work must therefore be explicit.
Likewise, a TDD cost allowance is not a tender price. A detailed budget requires diagnosis, design, quantities and market testing. False precision without supporting information can be more misleading than a transparent range.
How the emphasis changes by client
- Buyer: red flags, condition, documents, remaining life, CAPEX and lawful use.
- Lender: protection of collateral value, urgent expenditure, insurability and resilience of income.
- Portfolio owner: consistent data, asset comparison, renewal priorities and multi-year TOTEX.
- Vendor: a vendor survey to resolve ambiguity before the data room opens and prepare credible answers for bidders.
Professional sources
