The report, by Arup and the UK Climate Impacts Programme, examines how climate change is likely to impact on the built environment.
The revelation comes in the wake of reports yesterday from leading US scientists warning that the area covered by sea ice in the Arctic has shrunk for a record fourth consecutive year.
Richard Rogers, who wrote the foreword to 'Beating the Heat: Keeping UK Buildings Cool in a Warming Climate', said: 'The findings of this report indicate that there will be increasing challenges to designing a sustainable built environment over the next 100 years.
'Designers will require greater creative skills and better understanding of building performance.'
The report uncovers that as early as the 2020s schools, offices and homes in the south-east of England could face overheating if they rely purely on the UK's traditional method of cooling - opening a window.
This is because as climate change progresses, outside air will frequently be warmer than the temperatures which building occupants endeavour to achieve inside.