The creation of more therapeutic environments for dementia care may well require substantial change in the traditional roles of client, planner, designer, and researcher; such 'shifting balances' may be essential if we are to reconceptualise the ways in which our society defines and provides places for care of the cognitively impaired. Many of these changes in roles, wies, and conceptualisation of place were presaged more than fifty years ago by Kurt Lewin in his formulation of action research. Building upon Lewin's model, we identify six conditions necessary for effecting environmental and social change. Projects directed toward the creation of more therapeutic environments for dementia care -carried out by a range of researchers and care providers over the past two decade- are then briefly reviewed to illustrate and reinforce these six preconditions for environmental change. Lewin argued that the implementation of social change -whether this be change as ambitious as reducing racial prejudice or as seemingly prosaic as increasing consumption of beef hearts in support of the war effort- first requires 'unfreezing of the situation'; some 'additional force' is required to overcome an 'inner resistance' to change. In the context of environments for the elderly and infirm, the emergence of public and professional awareness of the enormous social and economic costs of Alzheimer's disease and related dementias has played a powerful role in unfreezing our understanding of what nursing homes are 'supposed to be'.