Commercial property investment losses are typically not the result of unforeseeable events. They usually come from a small set of recurring mistakes that buyers and their advisers either fail to identify or actively choose to ignore. The mistakes are well-known to experienced market participants; the discipline is in applying the framework consistently rather than rationalising around it on each specific deal.
This guide covers the principal commercial property investment mistakes we see across the market. Each is presented with the typical reasoning that produces the mistake, the actual outcome, and the buyer-side discipline that prevents it.
The mistakes don't change. The deal-specific rationalisations do. A buyer who recognises the recurring patterns avoids most of them; the buyer who treats each deal as unique relearns them at cost.
Mistake 1: Buying on Gross Yield
The reasoning
The agent quotes a headline gross yield; the buyer compares it to their cost of capital and concludes the deal works.
The actual outcome
Net yield after outgoings, vacancy allowance, and capex reserves is materially lower than the gross. The deal that worked at 8% gross might be marginal at 5.5% net. Cash flow disappointments emerge in year 1.
The discipline
Always underwrite at net yield, calculated from disclosed outgoings, realistic vacancy assumption, and a capex reserve. Gross yield is a marketing number; net yield is the buying number.
Mistake 2: Ignoring the Lease Structure
The reasoning
The headline numbers (rent, term, tenant name) look good; the buyer accepts the lease without detailed review.
The actual outcome
The lease has unfavourable provisions: short options, capex caps that don't cap, market reviews with hard floors, recovery clauses that don't recover. The headline numbers are correct; the actual cash flow is materially worse.
The discipline
Read every lease in full. The lease abstract should cover every commercial provision: rent reviews, options, outgoings recovery, make-good, capex liability, indemnity. The lease is the asset.
Mistake 3: Underestimating Tenant Covenant Risk
The reasoning
The tenant has been in the building for years; the rent has been paid on time; the business looks fine from the outside.
The actual outcome
The tenant's business model is in structural decline. The next 24 months produce a request for rent abatement, then a lease renegotiation, then a vacancy. The covenant that looked strong was actually deteriorating.
The discipline
Test the covenant. Audited financials where available; sector trajectory analysis; rent-to-revenue ratio. Strong-looking tenants in structurally weak sectors are not strong covenants.
Mistake 4: Buying in a Submarket the Buyer Doesn't Understand
The reasoning
The asset class is familiar; the buyer extends from established submarkets into new ones based on yield.
The actual outcome
The new submarket has different demand drivers, different lease structures, different competitive dynamics. The yield premium reflected real risks the buyer didn't price.
The discipline
Either invest the time to understand a new submarket properly or stay in submarkets the buyer knows. Yield premium without underwriting capacity is leverage on ignorance.
Mistake 5: Skipping or Skimping on DD
The reasoning
The deal is moving quickly; comprehensive DD would slow it down; the basic checks (title, planning) seem sufficient.
The actual outcome
A material issue surfaces post-settlement: contamination, structural defect, lease dispute, regulatory order. The cost dwarfs the DD spend that would have caught it.
The discipline
DD is non-negotiable. The cost of comprehensive DD on a $5 million acquisition is $15,000 to $50,000. The savings from catching one material issue justifies the spend.
Mistake 6: Mismatch Between Hold Period and Lease Term
The reasoning
The buyer plans a 10-year hold; the lease has 3 years to expiry; the buyer assumes renewal is the base case.
The actual outcome
The tenant doesn't renew. The asset goes vacant in year 3 of a 10-year hold. Re-leasing takes 12 months; the new rent is below the previous rent; capex on fit-out for the new tenant is substantial. The 10-year hold produces materially lower returns than modelled.
The discipline
Hold strategy should align with lease structure. Long holds on short-WALE assets require active asset management and realistic re-leasing assumptions.
Mistake 7: Over-Leveraging
The reasoning
The bank's maximum LVR is the practical limit; the buyer uses it to maximise capital efficiency.
The actual outcome
At refinance 3 to 5 years later, market conditions or the asset's performance produce a valuation below acquisition. The LVR is reset to the lower value; the buyer must contribute additional equity or partially sell. The capital efficiency at acquisition becomes capital constraint at refinance.
The discipline
Maintain LVR headroom. The bank's maximum is not the buyer's optimum. 60% to 65% LVR provides resilience to valuation movements.
Mistake 8: Buying Off the Wrong Comparable Evidence
The reasoning
The buyer's view of fair price is anchored to one or two recent transactions; the agent provides supporting evidence; the deal is priced on the comparable.
The actual outcome
The comparable was a stretched price for that specific transaction (a special-purpose buyer, an early-cycle compression). The buyer's deal sits at a price that requires the same stretching dynamic to repeat at exit. It doesn't.
The discipline
Use multiple comparable transactions across multiple periods. Understand the buyer profile and circumstances behind each comparable. Stretch trades are evidence of yesterday's market, not today's.
Mistake 9: Ignoring Capex Liability
The reasoning
The building inspector's report is moderate; the buyer focuses on current income and forward growth.
The actual outcome
Three years in, the HVAC needs major replacement, the roof needs recoating, the fire systems need upgrading. The capex sequence over the hold period is $500,000 against an asset that generates $300,000 a year net. The return shrinks dramatically.
The discipline
The building inspector should provide a 5 to 10 year capex schedule with cost estimates. The buyer-side model includes the capex; the headline yield is gross of capex; net-of-capex return is the meaningful number.
Mistake 10: Confirmation Bias in DD
The reasoning
The buyer has emotionally committed to the deal. DD becomes a process of confirming the decision rather than testing it.
The actual outcome
Warning signs are noted but rationalised. The deal proceeds. Problems emerge that were visible in DD but not actioned.
The discipline
Treat DD as a hypothesis-testing exercise, not a confirmation exercise. Engage advisers who will give frank feedback. Walk-away rates above zero are healthy; consistently 100% deal-closure on advanced positions suggests the screening process is not robust.
Mistake 11: Underestimating Operating Burden
The reasoning
The investor models the deal as a passive cash flow. Property management is assumed to be a small operational item.
The actual outcome
Multi-tenant management is substantial. Tenant disputes, leasing on vacancy, outgoings reconciliation, capex coordination, regulatory compliance all consume time and attention. The investor's time becomes the constraint.
The discipline
Model the operating burden honestly. Multi-tenant retail and office require active management; single-tenant industrial requires far less. Match the asset class to the investor's available time and capacity.
Mistake 12: Wrong Structure
The reasoning
The investor uses the structure they have, not the structure that fits the asset.
The actual outcome
Land tax aggregation produces a substantial recurring cost. CGT outcome at sale is worse than necessary. Succession is complicated. The structure choice at acquisition affects every aspect of the holding period.
The discipline
Structure decision before contract. Discretionary trust, unit trust, SMSF, individual ownership each have different applications. The accountant and solicitor should be engaged at the brief stage, not just at the contract stage.
Frequently Asked Questions
Are these mistakes really repeated this often?
Yes. The patterns are stable across cycles and buyer cohorts. Experienced buyers and advisers internalise the framework; first-time and infrequent buyers tend to repeat the patterns.
What's the single most important mistake to avoid?
If forced to pick one: confirmation bias in DD. Most other mistakes are catchable if the DD process is genuinely critical.
How can I tell if my adviser is doing real DD?
Written DD reports with specific findings, prioritised action items, and recommendations to renegotiate or walk away on appropriate triggers. DD that produces only confirmation of the deal as initially structured is not real DD.
Does using a buyer's agent prevent these mistakes?
A good buyer's agent applies the framework systematically across briefs. The framework prevents the mistakes; the agent is the operational discipline that ensures it is applied.