A geotechnical design methodology for horizontal and vertical equilibrium of retaining walls has been developed which considers the wall friction conditions appropriate for the excavation sequence and vertical loading conditions. The methodology is compatible with EC7, builds on the guidance of CIRIA C580, and has been developed from experience on previous large infrastructure projects in the UK, including the Channel Tunnel Rail Link and Crossrail. Recommendations for retaining wall design for the Ultimate Limit State during the excavation stage have been proposed, incorporating compatible wall friction assumptions for both lateral stability and vertical capacity checks. The design methodology also provides guidance for the design of retaining walls to resist upilift actions. The methodology provides a robust design and would be appropriate for the design of retaining walls for deep excavations.