Excavation of a new 6 m deep basement was required as part of the development of a city centre site in London. The proposed excavation was within a very congested former car park area and would take place immediately adjacent to a row of 5 storey Georgian town houses, many of which were founded on shallow strip footings. In order to demonstrate that the proposed method of basement excavation would have a negligible effect on the existing properties a detailed Finite Element (FE) analysis of the various stages of basement construction was undertaken. This allowed action levels to be set for monitoring and provided the necessary assurance to the owners of adjacent properties.