Buying commercial property in Australia is a fundamentally different exercise from buying a house. The due diligence required is broader, deeper, and more technically demanding. A residential buyer might get away with a building and pest inspection and a solicitor's review of the contract. A commercial buyer who takes that approach is asking for trouble.

Commercial property due diligence covers legal title and encumbrances, zoning and planning compliance, building condition and safety systems, environmental risk, tenant quality and lease terms, financial performance, and council requirements. Miss any one of these areas and you risk inheriting a problem that costs more to fix than the property is worth.

This guide sets out the full due diligence process for buying commercial property in Australia -- what to check, why it matters, who should do it, and how long it takes. Whether you are acquiring a neighbourhood retail strip, an office suite, a warehouse, or a multi-tenanted investment, the principles are the same. The depth of investigation scales with the complexity of the asset.

1 Pre-Contract Checks: Before You Sign Anything

Due diligence formally begins once you have a signed contract with a due diligence clause, but the smart work starts before that. Pre-contract checks help you decide whether the property is worth pursuing at all -- and whether the asking price reflects reality or aspiration.

Verify the income. Request the last two years of profit and loss statements for the property, along with current lease documents. Compare the stated net income to the actual bank deposits if possible. Vendors frequently present "pro forma" income figures that assume full occupancy and no arrears. You need the actual numbers.

Check the zoning. Look up the property on the relevant state planning portal (e.g., VicPlan in Victoria, NSW Planning Portal, or MyDAS in South Australia). Confirm the zoning permits the current use and -- critically -- any use you may intend for the property in the future. A building currently used as a medical centre in a Commercial 1 zone is very different from the same building in a Mixed Use zone with a Heritage Overlay.

Identify obvious red flags. Drive past the property at different times of day. Check for visible structural issues, poor access, limited parking, neighbouring uses that could affect value (waste facilities, licensed premises, industrial operations), and general precinct condition. Talk to neighbouring tenants and business owners if you can. They will tell you things the agent will not.

Review the contract structure. Have your solicitor review the contract of sale before you sign, not after. Pay particular attention to the length and terms of the due diligence period, any special conditions, GST treatment (going concern vs taxable supply), and what happens if the due diligence reveals problems. You want an unconditional right to terminate during the DD period, not a negotiation framework.

2 Legal Due Diligence

Legal due diligence is the backbone of the entire process. Your commercial property solicitor will conduct most of this work, but you need to understand what they are looking for and why each element matters.

Title Search and Ownership

A title search confirms who owns the property, the legal description of the land, the lot and plan number, and the total area. It also reveals any encumbrances registered on the title -- mortgages, caveats, covenants, easements, and other interests that affect your rights as the new owner. Every single encumbrance must be investigated and understood before settlement.

Easements and Covenants

Easements grant third parties specific rights over the property -- typically for services (drainage, sewerage, electricity, telecommunications) or access. A drainage easement running through the middle of a development site fundamentally changes its value. A right-of-way easement allowing a neighbour to drive across your car park affects both amenity and liability.

Restrictive covenants limit what you can do with the property. Common examples include height restrictions, use restrictions, building material requirements, and setback obligations. Some covenants are decades old and may be unenforceable, but removing them requires a Supreme Court or VCAT application that takes time and money.

Zoning and Planning Permits

Your solicitor should obtain a full planning certificate (called different things in different states -- Section 10.7 certificate in NSW, Planning Property Report in Victoria) that confirms the current zoning, any overlays, and whether any planning permits have been issued or are pending for the property or adjacent properties.

Overlays are particularly important. A Heritage Overlay, Design and Development Overlay, Environmental Significance Overlay, or Special Building Overlay can all impose significant restrictions on future development, renovation, or even minor alterations. These overlays survive the sale and bind you as the new owner.

Encumbrances and Charges

Beyond what appears on the title, your solicitor should search for any outstanding rates, land tax, water charges, or body corporate levies. Unpaid charges can, in some jurisdictions, create a charge over the property that survives settlement. The solicitor should also search the Personal Property Securities Register (PPSR) to check whether any of the fixtures, plant, or equipment included in the sale are subject to a security interest held by a third party.

3 Building and Physical Inspections

A commercial building inspection is not a scaled-up version of a residential inspection. It requires specialists who understand commercial construction, fire safety systems, hydraulic services, and compliance obligations that do not apply to houses.

Structural Assessment

Engage a structural engineer or experienced commercial building inspector to assess the structural integrity of the building -- foundations, load-bearing walls, roof structure, concrete condition (especially in older tilt-panel or pre-stressed concrete buildings), and any signs of movement, cracking, or water damage. For older buildings, ask specifically about concrete cancer (alkali-silica reaction), which is expensive to remediate and common in 1970s and 1980s commercial buildings along the east coast.

Asbestos

Any commercial building constructed or renovated before 1990 should be assumed to contain asbestos until proven otherwise. Under workplace health and safety legislation in every Australian state, the owner of a commercial building must maintain an asbestos register and management plan. Request the existing register. If one does not exist, commission a Division A asbestos survey before settlement. The presence of asbestos is not necessarily a deal-breaker -- most commercial buildings of that era contain it -- but the condition and location of the asbestos-containing materials, and the cost of future management or removal, must be factored into your price.

Fire Safety and Essential Safety Measures

Every commercial building in Australia has fire safety obligations, and these are the owner's responsibility. Request the Essential Safety Measures (ESM) report or Annual Fire Safety Statement (AFSS), depending on the state. This document confirms that all fire safety systems -- sprinklers, hydrants, alarms, emergency lighting, exit signs, smoke detectors, fire doors, and mechanical ventilation -- have been inspected, tested, and maintained in accordance with the Building Code of Australia.

If the ESM report is out of date or non-existent, that is a significant red flag. Bringing a building into fire safety compliance can cost anywhere from $20,000 for minor works to several hundred thousand dollars for a building with systemic failures. Get a fire safety engineer's opinion before you commit.

Electrical, Hydraulic, and Mechanical Systems

For larger commercial assets, engage specialists to assess the condition and remaining useful life of the electrical switchboard and wiring, the hydraulic systems (water, gas, trade waste), and the mechanical systems (HVAC, lifts, car stackers). These are capital-intensive items. Replacing a commercial HVAC system in a multi-storey office building can cost $150,000 to $500,000 or more. You need to know what is coming in the next five to ten years.

Accessibility Compliance

Under the Disability Discrimination Act 1992 (Cth) and the relevant state building regulations, commercial buildings must provide reasonable access for people with disabilities. Non-compliance creates legal liability for the building owner. Check for compliant entry access, accessible bathrooms, compliant signage, and adequate circulation space. Buildings undergoing a change of use or significant renovation will typically trigger an obligation to upgrade to current accessibility standards.

4 Environmental Assessments

Environmental due diligence is essential for any commercial property, and critical for industrial assets, petrol stations, dry cleaners, and any property where hazardous materials may have been used, stored, or disposed of on site.

Contamination

Start with a Phase 1 Environmental Site Assessment (ESA) -- a desktop review of the property's history, previous uses, and any records on the relevant state EPA contaminated sites register. If the Phase 1 identifies potential contamination (as it often does for industrial and former industrial sites), a Phase 2 ESA involves soil and groundwater sampling to determine the nature and extent of contamination.

Contamination clean-up costs can be catastrophic. Remediation of a moderately contaminated industrial site in a metro area routinely costs $500,000 to $2 million, and complex sites can exceed $10 million. In most Australian jurisdictions, the polluter-pays principle applies -- but if the original polluter no longer exists or cannot be found, the liability falls on the current landowner. This is not a risk you can afford to discover after settlement.

Flood and Bushfire Overlays

Check the planning scheme overlays and council flood maps for any Land Subject to Inundation Overlay (LSIO), Special Building Overlay (SBO), Floodway Overlay, or Bushfire Management Overlay (BMO). These overlays affect insurance costs (sometimes dramatically), development potential, building requirements, and -- in the case of floodway overlays -- may restrict the type of goods that can be stored on the ground floor of a warehouse or the viability of certain uses altogether.

Request the property's insurance history from the vendor, including any flood or storm damage claims. Check with two or three insurers for indicative premiums before committing to the purchase. Some properties in high-risk flood zones have become effectively uninsurable at reasonable cost.

Contaminated Land Registers

Every state maintains a register of contaminated or potentially contaminated sites. In Victoria, this is the Priority Sites Register maintained by EPA Victoria. In NSW, it is the Contaminated Land Record maintained by the EPA. In Queensland, the Environmental Management Register and Contaminated Land Register are maintained by the Department of Environment and Science. Your environmental consultant should search the relevant register as part of the Phase 1 ESA, but your solicitor should independently confirm as well.

5 Tenant Analysis and Lease Review

For any tenanted commercial property, the quality of the tenants and the terms of their leases are arguably more important than the physical building itself. You are buying an income stream. The lease documents define exactly what that income stream looks like, how long it lasts, and what happens when it ends.

Tenant Covenant Strength

A tenant's "covenant" is their financial capacity to meet their lease obligations for the full term. A ten-year lease with a nationally listed company is a fundamentally different proposition from a ten-year lease with a two-year-old sole trader. Assess each tenant by reviewing their financial statements (if available), searching ASIC for their company details and any history of insolvency, and checking their payment history with the current landlord.

For retail properties, check whether the tenant's business appears viable for the remaining lease term. A struggling cafe with three years left on the lease is a vacancy waiting to happen, regardless of what the lease document says.

Lease Terms and Rent Reviews

Read every lease in full. Do not rely on the vendor's lease summary. The specific terms you must understand include:

Rental Arrears and Disputes

Request a current rent roll showing each tenant's payment history, any outstanding arrears, and any rent abatements or incentives that have been granted. Incentives are common in commercial property and can significantly affect the true net income. A lease showing $200,000 per annum in face rent with a twelve-month rent-free incentive amortised over the lease term has an effective rent well below the face figure.

6 Financial Due Diligence

Financial due diligence confirms that the property's income and expenses match what the vendor has represented and that there are no hidden costs waiting for you after settlement.

Outgoings Reconciliation

Request the last three years of outgoings statements, including council rates, water rates, land tax, insurance premiums, body corporate levies (for strata properties), management fees, and any other recurring costs. Compare these to the figures in the vendor's marketing material. Look for costs that have been omitted, understated, or are about to increase.

Pay particular attention to land tax. In most states, land tax is assessed on the aggregated value of all land held by the owner in that state. If you already own other properties, acquiring a commercial asset may push your total holdings into a higher land tax bracket, significantly increasing the effective cost of ownership.

Capital Expenditure History

Request a schedule of all capital works undertaken in the last five to ten years, along with any planned or deferred capital expenditure. The key question is: what major works are needed in the next five years? Common capital items in commercial property include roof replacement, car park resurfacing, lift modernisation, HVAC replacement, facade remediation, and fire safety upgrades. Each of these can cost six figures.

If the vendor has been deferring maintenance to maximise short-term net income before sale -- a common tactic -- you will inherit the backlog. Factor deferred capex into your purchase price negotiation.

Body Corporate and Strata

For strata-titled commercial properties, obtain the last three years of body corporate minutes, the current financial statements, the sinking fund balance, and any special levies that have been proposed or approved. A body corporate with a healthy sinking fund and a well-maintained building is a different proposition from one that has been underfunding its sinking fund for years and is about to impose a $100,000 special levy on each lot owner.

7 Town Planning Risk

Town planning risk is the risk that future changes to the planning scheme, government policy, or surrounding development will negatively affect your property's value or usability.

Proposed planning scheme amendments. Check with the local council and state planning authority for any proposed amendments to the planning scheme that could affect your property. A rezoning of the surrounding area from industrial to residential, for example, could either increase your land value (if your site is included) or damage your tenants' operations (if neighbouring complaints about noise or traffic increase).

Infrastructure projects. Major road widening, new rail lines, level crossing removals, and infrastructure corridors can all affect commercial property -- positively through improved access, or negatively through compulsory acquisition, construction disruption, or loss of on-street parking. Check the state's infrastructure pipeline and any gazetted corridor reservations.

Neighbouring developments. Search the council's planning register for any permit applications on neighbouring sites. A large-scale residential development next door can bring foot traffic to a retail asset or create conflict for an industrial operation. A competing commercial development nearby can dilute your tenant demand and rental income.

Highest and best use. Consider whether the property's current use represents its highest and best use under the planning scheme. A single-storey retail building on a large site zoned for mixed-use development at eight storeys may be worth significantly more as a development site than as a retail investment. Conversely, if you are paying a development-site premium, make sure the planning pathway actually supports the assumed development.

8 Council Requirements and Compliance

Local councils impose a range of ongoing obligations on commercial property owners that can affect both cost and liability.

9 Due Diligence Timeline: How Long Do You Need?

The due diligence period for commercial property in Australia is negotiable and should be agreed in the contract of sale. As a practical guide:

The timeline depends on how quickly you can access information from the vendor, how responsive the council is to enquiries, and how available your consultants are. Start engaging your solicitor, building inspector, and environmental consultant before you sign the contract so they can begin work immediately once the DD period commences.

The cost of thorough due diligence is always a fraction of the cost of the problems it prevents. A $15,000 to $30,000 due diligence spend on a $2 million commercial property is not an overhead -- it is the most important investment protection you will make.

Pulling It All Together

Commercial property due diligence is not a single event -- it is a coordinated process involving your solicitor, building inspector, environmental consultant, accountant, and (ideally) a buyer's agent who has done this dozens of times before. Each professional covers a different area of risk, and the findings from one area often affect the analysis in another.

The goal is not to find a property with zero issues. Every commercial property has issues. The goal is to identify every material issue before you commit, quantify the cost or risk associated with each one, and make a fully informed decision about whether the property -- at the agreed price and on the agreed terms -- represents a sound investment.

If it does, you proceed with confidence. If it does not, you exercise your due diligence termination right and walk away. That is not a failed transaction -- that is due diligence doing exactly what it is supposed to do.

If you are considering a commercial property acquisition and want experienced support through the due diligence process, we are here to help.