A replacement ratio of 1.33 is applied for offsets with a time to maturity of between 5 and 25 years and 1.67 for those with time to maturity between 25 and 100 years (de Bie and van Dessel, 2011). The size of the replacement ratio applied is usually related to the assessed risk that an offset will successfully mature (McKinney and Kiesecker, 2010). Guidance material for the biodiversity offset pilots in England, for example, recommends multipliers of ten times the measured size of the clearing site for habitats that are classified as having a “very high difficulty of restoration/recreation” (DEFRA, 2012).