Book excerpt: The structural analysis of multi-storey buildings can be carried out using discrete (computer-based) models or creating continuum models that lead to much simpler albeit normally approximate results. The book relies on the second approach and presents the theoretical background and the governing differential equations (for researchers) and simple closed-form solutions (for practicing structural engineers). The continuum models also help to understand how the stiffness and geometrical characteristics influence the three-dimensional behaviour of complex bracing systems. The back-of-the-envelop formulae for the maximum deflection and rotation, load shares, fundamental frequency and critical load facilitate quick global structural analysis for even large buildings. It is shown how the global critical load ratio can be used for monitoring the "health" of the structure acting as a performance indicator and "safety factor". Evaluating the results of over sixteen hundred calculations, the accuracy of the procedures is comprehensively demonstrated by comparing the discrete and continuum results. Nineteen worked examples illustrate the use of the methods, whose downloadable MathCad and Excel worksheets (www.crcpress.com/ 9780367350253) can also be used as templates for similar practical situations.