Use the same objective, cost definitions and downside assumptions for each property. Keep evidence and unanswered questions alongside the numbers.
Write one brief for both properties
A comparison starts with an objective. State the budget, expected holding period, funding method and the outcome you want. These are the same for both options; otherwise you risk choosing whichever brochure tells the more attractive story.
Separate your non-negotiables from preferences. For a home, a school journey or accessibility need may outweigh a projected yield. For an investment, a lower entry price can still be poor value if operating costs or rental assumptions do not work.
Compare like with like
Use the same currency, floor-area convention, cost categories and calculation period. State whether the quoted price includes any incentives, furniture or fees. Do not mix asking rents with achieved leases without identifying the difference.
Check whether your comparison uses built-up area, saleable area, internal area or another measure. Price per square foot only helps when the underlying area definitions are consistent.
Put a source beside each number
Keep the date, source and exact scope of each comparable. One high advertised rent is not a rental market. A community average can hide differences in building quality, unit layout, view, floor and tenancy conditions.
Mark unsupported entries as questions rather than filling them with optimistic assumptions. The most useful comparison sometimes shows that you need another document or an inspection before making a choice.
Make the downside symmetrical
Apply the same rent reduction, vacancy allowance and exit assumptions to both options. For an off-plan property, include payment timing and a delayed-income scenario. For a ready property, include condition, current tenancy and maintenance needs.
A simple score can help organise a discussion, but it should not hide the reason for the decision. Write one sentence explaining the strongest advantage and the largest unresolved risk for each property.
Keep a useful decision record
The comparison worksheet lets you record two options, save the entries in your own browser and download a CSV to share. It does not automatically rank investments or verify your inputs.
Use it to bring a more specific brief to the conversation: “This option fits the income goal, but the service charges and exit demand are still unverified.” That is a better starting point than a preferred unit number alone.
Open the comparison worksheetNumerical examples are illustrative. Check project documents and current official guidance for your transaction.
How the research approach works → Discuss the assumptions in your brief →