Validation

Fair-value estimates vs later sales

Each test recreates an estimate using only transactions dated before a recorded sale, then compares that estimate with the sale price. Comps are the same town for HDB, or the same district for private, the same type, and a similar floor area. Block, floor, and project are optional on the form, so they are not required here. The published range is the middle half of those comps (P25–P75), so about half of later sales should land inside it. A sale just outside the range can still be close to the median. This sample takes up to 40 recent sales per location. Public records omit condition, so this measures error rather than proving a valuation.