Part 1 of this information paper provides an overview of a service life design system developed by BRE for reinforced concrete structures. This system can be used to assist structural designers in meeting their client's requirements for service life, functionality and maintenance. It includes best practice guidance for undertaking a client brief, designing for durability and effective execution and maintenance. 8 pages. The guidance in all three parts is combined with the output from specialised models for concrete deterioration to provide a holistic service life design system. Part 2 focuses on optimising the durability design for a structure and Part 3 covers service life forecasting and enhancement. Contents of Part 1: Introduction Overview of the service life design process Client brief requirements Environmental loads Design for durability and service life The design process Maintenance strategy Concluding remarks References and further reading