By Borough
Basement Conversion Drawings by London Council
Borough-by-borough guidance on basement conversion drawings — local conservation areas, Article 4 directions and validation quirks for each council.
Ealing
London Borough of EalingWandsworth
London Borough of WandsworthBarnet
London Borough of BarnetHarrow
London Borough of HarrowRichmond
London Borough of Richmond upon ThamesIslington
London Borough of IslingtonHaringey
London Borough of HaringeyCroydon
Croydon CouncilRedbridge
London Borough of RedbridgeMerton
London Borough of MertonNewham
London Borough of NewhamHavering
London Borough of HaveringBarking & Dagenham
London Borough of Barking and Dagenham
London Borough of EalingWandsworth
London Borough of WandsworthBarnet
London Borough of BarnetHarrow
London Borough of HarrowRichmond
London Borough of Richmond upon ThamesIslington
London Borough of IslingtonHaringey
London Borough of HaringeyCroydon
Croydon CouncilRedbridge
London Borough of RedbridgeMerton
London Borough of MertonNewham
London Borough of NewhamHavering
London Borough of HaveringBarking & Dagenham
London Borough of Barking and Dagenham
Basement Conversion Drawings guides that apply in every borough
These are the same in all 33 councils, so they are worth reading once rather than borough by borough.