A potentially sensitive excavation was undertaken to construct the foundations for a new building at the Altnagelvin Hospital, Londonderry. The original proposal was to underpin with concrete the side of the excavation that was situated within metres of the elderly care ward, however a faster and more economical solution was proposed using Stabilisure micro soil nails in combination with an erosion protection mat. The micro soil nails are able to be left in place when a permanent retaining system is proposed, and can be considered to improve the long term stability of the retained soil, which may be used to reduce the construction width of the permanent retaining system.