The BRE service life design system is a systematic approach to assist the designer in meeting the client's requirements for a structure, in terms of service life and functionality. This information paper forms the third part of a 3-part series which together describe the approach to service life design adopted in the BRE system. It details the prediction of actual service life and the provision of measures available to the designer to enhance service life should it be deemed necessary. Table 1 lists the factors that can affect the service life of components and Table 2 describes the likely extension in service life from additional protection strategies. Another table shows how additional resistance measures can be combined. Table 8 shows the types of measures (repairs, sacrificial layers, corrosion inhibitors, etc.) which could be considered in order to increase the service life of the structure after a number of years and gives a general indication of the additional service life which could result. However, they do not represent a guaranteed service life extension in every situation so should not be used to justify maintenance actions currently being considered on an existing structure. 8 pages.