In both its absence and abundance – drought and flooding – water will pose one of the most serious challenges to society in the 21st century. In this issue, an important article calls for a complete rethink to our approach, with buildings and cities designed to make space for water rather than trying to keep it out. Other pieces look at improving the energy efficiency of existing stock, domestic overheating and ventilation, and the features that can dramatically affect ease of access and use in new developments. This issue also covers how RICS is taking the initiative on sustainability and risk management and has been researching the performance of membership assessment.