ABSTRACT
The method of whole-life costing that was described in Chapter 2 involves analysing cashflow data about costs and benefits through the study period, so data is typically required for 20 to 30 years after the construction of a building is finished. Of necessity, this data about future events is estimated – and subject to varying levels of uncertainty. The mathematical calculation of net present value gives very precise answers, but the precision is more or less illusory due to uncertainty in the cashflow data.
