Here is a table listing the specified pieces of legislation, some linked to the legislative source, along with their approximate lengths:
This is not an exhaustive list but just a personal summary of some of the legislation relevant to town planning in the UK. Summing the maximum values of these ranges provides an approximate total length of 1,045 pages. Please note that these are estimated lengths and can vary based on formatting and publication versions. It does not show lengths of PANs. It is interesting that consecutive governments prioritise simplification and reduction of red tape and consecutive governments introduce further legislation that objectively increases administrative complexity.
Interesting paper on complexity as it relates to English Law