Your initial calculations will cover all sources of energy consumption, but when doing the full audit you are allowed to exclude specific areas of organisational activity, covering up to 5% of total consumption. This might mean leaving out a specific site, or consumption relating to a particular activity or fuel. This excluded proportion of energy use is known as your de minimis. The de minimis rule applies if you are following alternative routes to Phase 3 compliance such as ISO 50001 certification – compliance only has to apply to the other 95% of consumption sources. If an area of the business is excluded as de minimis, you will not get any energy-saving recommendations relating to this area of the business. Many businesses will choose not to take up the de minimis option and instead include 100% of their energy consumption sources in their ESOS report, to get maximum benefit from the ESOS process. If you do choose to use this option, your ESOS report should state what percentage of your energy use is being classed as de minimis. Although you could class up to 10% as de minimis in Phase 2, for Phase 3 the maximum is 5%.