This paper examines the issue of instrumentation for civil structures and in particular discusses the role of sensing systems in the evolution of the smart building concept. The sheer size of most structures of interest presents its own technological challenge in designing a suitable sensing architecture which will also conveniently address the area to be covered and will also provide sufficient sensing points to adequately characterize the structure under test. In addition, the measurement problem itself, which comprises both process monitoring and in use assessment must be defined. The former is very much process specific and may range from assessing whether concrete is dry to ensuring that protective materials are properly installed. The latter is almost entirely concerned with providing an alarm for either the onset of unacceptable corrosion within the structure or the appearance of physical damage for example due to foundation failure. This paper presents an analysis of the principal issues which the civil engineering smart structure must address and derives generic system specifications. It continues to argue that fiber optic solutions are the most appropriate sensing technologies and examines a number of distributed fiber optic technologies which enable both physical and chemical parameters to be addressed throughout a large structure.