By Borough
Double Storey Extension Drawings by London Council
Borough-by-borough guidance on double storey extension drawings — local conservation areas, Article 4 directions and validation quirks for each council.
Ealing
London Borough of EalingWandsworth
London Borough of WandsworthBromley
London Borough of BromleyBarnet
London Borough of BarnetHarrow
London Borough of HarrowRichmond
London Borough of Richmond upon ThamesCamden
London Borough of CamdenIslington
London Borough of IslingtonLambeth
London Borough of LambethSouthwark
London Borough of SouthwarkWaltham Forest
London Borough of Waltham ForestHackney
London Borough of HackneyHaringey
London Borough of HaringeyHammersmith & Fulham
London Borough of Hammersmith & FulhamKensington & Chelsea
Royal Borough of Kensington and ChelseaWestminster
Westminster City CouncilGreenwich
Royal Borough of GreenwichLewisham
London Borough of LewishamCroydon
Croydon CouncilRedbridge
London Borough of RedbridgeEnfield
London Borough of EnfieldHounslow
London Borough of HounslowKingston
Royal Borough of Kingston upon ThamesMerton
London Borough of MertonSutton
London Borough of SuttonBrent
London Borough of BrentNewham
London Borough of NewhamTower Hamlets
London Borough of Tower HamletsHavering
London Borough of HaveringBexley
London Borough of BexleyHillingdon
London Borough of HillingdonBarking & Dagenham
London Borough of Barking and Dagenham
London Borough of EalingWandsworth
London Borough of WandsworthBromley
London Borough of BromleyBarnet
London Borough of BarnetHarrow
London Borough of HarrowRichmond
London Borough of Richmond upon ThamesCamden
London Borough of CamdenIslington
London Borough of IslingtonLambeth
London Borough of LambethSouthwark
London Borough of SouthwarkWaltham Forest
London Borough of Waltham ForestHackney
London Borough of HackneyHaringey
London Borough of HaringeyHammersmith & Fulham
London Borough of Hammersmith & FulhamKensington & Chelsea
Royal Borough of Kensington and ChelseaWestminster
Westminster City CouncilGreenwich
Royal Borough of GreenwichLewisham
London Borough of LewishamCroydon
Croydon CouncilRedbridge
London Borough of RedbridgeEnfield
London Borough of EnfieldHounslow
London Borough of HounslowKingston
Royal Borough of Kingston upon ThamesMerton
London Borough of MertonSutton
London Borough of SuttonBrent
London Borough of BrentNewham
London Borough of NewhamTower Hamlets
London Borough of Tower HamletsHavering
London Borough of HaveringBexley
London Borough of BexleyHillingdon
London Borough of HillingdonBarking & Dagenham
London Borough of Barking and Dagenham
Double Storey Extension 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.