One of the assumptions it seems safe to make about the world is that the environment we surround ourselves with is largely inanimate, and in that lies some comfort: an environment that ‘knows’ about you, and can move and respond is the stuff of nightmares and horror films. So, how valid is that assumption? I will suggest that built environments already encapsulate knowledge; that they are also in a very real sense dynamic and change as you move through and experience them. If I am right about this, then it is not such a great leap to consider active and responsive environments which are physically dynamic, where sensors processors and actuators turn the environment into an active social agent. But, could such an environment be benevolent?