There are lots of different kinds of costs – fixed and variable costs, operational and capital costs. In planning project costs for small costs I like to distinguish between ‘cumulative’ and ‘lump-sum’ costs.
The cumulative costs are those that increase as you do more, or as tasks take longer – for example, when you are paying a contractor an hourly rate. The lump sum costs are those that will cost a particular amount – for example, when you have a quote from an electrician for lighting and power points. Lump sums can vary, but generally only...
