Used as an aid to steer a buildings design, cost in use calculations help ensure that the end result achieves best value for money.
These theoretical calculations are valid at a particular time and may not ultimately hold true. However, alternative or competing designs can be evaluated and compared using the same data set to give a high degree of confidence in the final design. Each proposal is evaluated using a number of different criteria usually starting with the initial construction cost, then adding annual running costs (electric, gas, oil,
water etc.), including maintenance and replacements; then the life expectancy of the building components is factored in to finally determine, over a set period of time, the wider cost of the differing designs.
‘What if’ questions can be asked and different factors such as changing insulation standards and energy costs can be considered to see how they influence the design options.
Broadly similar calculations may be required by organisations set to "inherit" a building project (perhaps from section 106 funding) and who want to be able to predict the running cost in order to influence the design or set a precept or to create a sinking fund.
The cost in use calculation is a relatively inexpensive exercise that can quickly repay the initial investment.