The impacts of climate change pose many threats to our current way of life. However, the current mitigation agenda has not yet produced the carbon emission reductions needed implying that some level of adaptation will be required. For buildings this is likely to mean either drastic changes to architecture, occupant behaviour or the increased use of artificial cooling to maintain thermal comfort in the future. The capital cost of sustainable buildings is often perceived to be higher than for conventional buildings and there is little incentive to employ sustainable building adaptations over air-conditioning type solutions, making future reductions in carbon emissions unlikely. In this paper we investigate contributing factors to worker productivity in an attempt to justify the perceived cost of sustainable adaptations. Then as a proof of concept we estimate the potential savings that could be achieved by applying two simple adaptations to an office building to produce a more comfortable environment. It is hoped that this consideration of loss of productivity and its causes will aid not only in the choice of useful adaptation decisions, but also a consideration of payback periods will help persuade building commissioners of their value and overcome the perceptions about sustainable buildings.