Cities are particularly prone to climate change: a high degree of soil sealing, a dense population and little vegetation lead to hot summers in cities. Climate adaptation is thus considered a more and more pressing need. Like climate change, climate adaptation challenges the “concept of time” espoused in traditional environmental law. It is “timeless” and based on a notion of the “great ecological transformation” (Klaus Ferdinand Gärditz). This article argues, however, that this timelessness does not conflict with the idea of democratic self-determination but rather furthers it. Climate adaptation planning is – in the existing legal framework – the only means to confine the equally timeless grandfathering of buildings under construction law.