Sources and methodology — a diagram of the key planning steps
Planning diagram. The same steps are described in the text below.

Reading the source list

Each guide links to a responsible authority or relevant official resource. Where the link is a broad starting point, it is labelled as such. Use the linked authority to check the procedure that applies to your circumstances.

Data comparisons

State the unit, geography, period and measurement method. Asking prices and transaction prices are different series; a municipal median is not an individual quote. The planning tools use the amounts you enter and clearly labelled examples.

Calculations

Budget tools add the categories you enter. The mortgage tool uses an equal-payment annuity formula and explicit constant-rate scenarios. Tax totals require confirmed amounts entered by the user; no unvalidated tax rate is applied automatically.