@www{davies2016regulations,
title={Building Regulations And {U-values}: How have they changed?},
author={Jon Davies},
year={2016},
month={01},
url={https://great-home.co.uk/building-regulations-u-values-how-have-they-changed/},
urldate={2023-09-20},
annote={Describes how English / Welsh / Scottish national building standards/regulations have changed over the years from when first published in the 1960s, including how U-values have dropped over the years.  Eg for walls in 1970 / 1980 / 1990 with U values of 1.6 / 1.0 / 0.6, and ceilings 1.5 / 0.68 / 0.4.  See also https://www.ecomerchant.co.uk/news/a-brief-history-of-building-regulation-u-values-with-examples/ },
}