This is a useful guidance document issued by Hertfordshire Building Control, download here:
https://www.hertfordshirebc.co.uk/wp-content/uploads/2023/11/HertfordsireBC-New-Gold-Guide-v10.pdf
This is a useful guidance document issued by Hertfordshire Building Control, download here:
https://www.hertfordshirebc.co.uk/wp-content/uploads/2023/11/HertfordsireBC-New-Gold-Guide-v10.pdf