The property due diligence checklist buyers actually need

What property due diligence actually means

Due diligence is not a survey and it is not a mortgage valuation. It is the structured work you do between 'I like this house' and 'here is my offer' — checking that what you are buying matches what you were told, and that the price reflects what you will actually spend over the next ten years.

Commercial buyers never skip it. Residential buyers usually do, because nobody hands them a checklist. This is that checklist: three tracks — financial, physical and legal — run in order, each one able to stop the purchase before you spend money on the next.

Track 1 — Financial due diligence

Asking price versus comparable sold prices in the last twelve months, on the same street or an equivalent one. Sold prices, never asking prices.

Total cost of ownership: mortgage, insurance, service charge, ground rent, local taxes, energy costs at the property's actual efficiency rating, and a maintenance reserve of roughly one percent of value per year.

Price history: how long has it been listed, has it been reduced, has a previous sale fallen through? Each of those is information the agent will not volunteer.

Exit liquidity: how quickly do properties of this type sell here when the market cools? A property you cannot sell is a cost, not an asset.

Track 2 — Physical due diligence

Roof age and condition, and the cost of the next replacement. Damp: rising, penetrating and condensation each have different fixes and very different bills.

Structural movement — cracks wider than a pound coin, sticking doors, sloping floors — plus any history of subsidence, underpinning or insurance claims.

Services: electrics, heating system age, plumbing, drainage. A boiler at year fourteen is a budget line, not a detail.

Insulation and energy performance, because it decides your running costs and your future retrofit bill.

Environment: flood maps, ground stability, radon, nearby planning applications, noise at 8am and 11pm, not just at the viewing hour.

Track 3 — Legal due diligence

Tenure. If leasehold: years remaining, ground rent and any escalation clause, service charge history and planned major works. A short lease or a doubling ground rent can quietly remove tens of thousands from the value.

For apartments with an owners' association, read the reserve fund, the minutes and any planned levies before you offer, not after.

Boundaries, rights of way, easements, covenants and shared access. Then permissions: was the extension, loft conversion or new bathroom signed off? Unpermitted work becomes your problem on the day you complete.

Finally, the chain and the seller's position — the most common reason a well-priced purchase collapses at week six.

Rate every finding, then price it

A checklist only helps if every item ends in a rating and a number. Score each finding Low, Medium or High on likelihood and on cost to fix, and attach a euro or dollar range to anything above Low.

The total of those ranges is your negotiation position. It turns 'the roof looks old' into 'the roof has roughly five years left and costs €14,000 to replace, so the offer reflects that.'

Running it with Home Compass

Doing all three tracks manually takes a weekend per property, which is why most buyers do it once — on the property they have already emotionally committed to.

Home Compass turns the checklist into a structured framework you paste into ChatGPT, Claude or Gemini with the listing details. It walks the same three tracks, asks you the questions an experienced buyer would ask, flags what is missing from the listing, and produces a written risk table with cost ranges and the exact questions to put to the agent and the surveyor.

Start with the Essential Edition on every shortlisted property, and run the Professional Edition before anything goes in writing.