Designing school buildings to respond to change is not a new idea. But perhaps what is different today is the kind and degree of change which we have to anticipate. The OECD is carrying out projects that can help in the planning and design of future educational facilities--exploring trends in education and studying innovative learning environments. Education planners have long grappled with the type of change connected with demography, for example changing local patterns in the number of school places needed over a period of time. But new challenges lie in the complexity and uncertainty which are characteristic of the 21st century world. The findings of the OECD's project "Schooling for Tomorrow: Trends Shaping Education" show some sources of this uncertainty, including falling birth rates, increasing economic globalisation and growing numbers of single parent families. Such issues suggest that policy makers and education providers alike need to address questions about what education is and how it should be delivered. Another OECD project, a study of innovative learning environments, is looking at how schools can respond to changes in the type of teaching and learning that make individuals lifelong learners. Developing individuals as self-directed learners, who are able to acquire expert knowledge in different fields and to change careers, benefits the economy and society generally. Research into learning shows both the importance of allowing students to take control of their own learning and that learning must be a social, cultural, intrapersonal and an active process. Research also demonstrates that an understanding of complex subjects can be best achieved in settings where the learner is engaged with others in the community, in activities where knowledge is being applied. The learning environments that support this must be fundamentally different from what has gone before, with less emphasis on teachers addressing a group of students in a traditional classroom setting. However, just how the physical environment must respond is a complicated issue. To meet the needs of 21st century learning, the physical environment will have to be agile so that it is capable of providing a mixed range of learning settings from large group spaces to smaller, more individual tutorial type spaces. However, the interaction between a building's users and the physical infrastructure is complex. The physical environment is always a constraint, but a key question might be to what extent does it offer the teachers the freedom and empowerment to do with it what they want. The different learning settings may be facilitated by clever use of furniture which can be easily rearranged in a variety of ways thus providing a range of spaces within spaces. These are all issues that future work of the Programme on Educational Building will explore further, building on the current OECD work on innovative learning environments. (Contains 2 figures.)