Define the question and time period
Specify the property, location, ownership period and financial measure you want to assess. A short period, a national average and one property's actual results answer different questions; do not combine them as if they were the same evidence.
Compare income with the full cost picture
Use dated records for rental income and relevant operating, financing and ownership costs. Note which amounts are actual, estimated or excluded. Do not infer an investment return from rent growth or a property-price change alone.
Use comparable inflation data
Choose a current authoritative inflation series for the same jurisdiction and period as the property figures. State the source, dates, calculation and limitations; do not reuse an unsourced historical average as a current forecast.
Get advice for an investment decision
Property, tax, borrowing and personal circumstances can affect an investment decision. Verify information with current primary sources and consult a qualified financial or tax adviser for advice about your situation.
