Scenario studies. The input for the brief usually comes from the current buildings users. It is obvious, however, that needs and users change over time, and a good brief should anticipate such changes, otherwise the building will be outdated by the time it is completed. Scenario studies can help to avoid this. They are a means to explore and understand possible future developments and their impact on spatial requirements. Scenarios can be based on changes in contextual factors, such as economics, climate, politics or technologies, and on client-specific variables such as organizational growth, user demographics and expected changes in the activities of the buildings users.The relevant factors will depend on the type of project. For a university building, for example, it will be useful to investigate how the rise of online courses may affect the need for auditoria. For an office project, it will be relevant to look at the emergence of new ways of working, such as working from home, and its impact on the need for desk space at the office. A very practical variable to consider in all scenarios is the number of users of the building and the use of space per user (see example on opposite page). Will the number of users remain constant, grow or shrink in the future? And how much space per user will be needed? Together, the answers to these questions determine the total space requirements and it is important to test how different combinations play out.The main challenge with scenario studies is the fact the scenarios are inherently speculative. Even the most plausible, best-researched scenarios will rarely play out as envisaged. There may be unexpected developments and projected changes may fail to materialize. But that does not diminish the usefulness of scenario studies. Thinking about the future is instrumental in the exploration of new accommodation solutions and it pushes clients and users to think beyond the status quo.Recommendations-Scenarios should be plausible, but not too cautious. Adding provocative or extreme scenarios can help to sharpen peoples thinking and their awareness of future change.-Look at existing scenario studies before developing ones own. There are plenty of scenario studies available on the Internet.-When making a scenario, differentiate between fairly certain developments (e.g. demographics) and less predictable developments (e.g. social change).-Do not look only forwards, but also backwards. This helps one gain an understanding of how quickly or slowly things change over time.-Differentiate between structural trends (long-term, wide-range) and passing fads or fashions (short-term, narrow-range). The first tend to be most relevant.