Every council in England works to its own local plan, and in parts of Southwark that plan sits alongside a second layer of control entirely. Much of Dulwich, covering SE21 and SE22, falls within the historic Dulwich Estate’s own private planning scheme, which homeowners need to satisfy on top of standard Southwark Council permission. Elsewhere in the borough, 48 conservation areas and a wide network of Article 4 Directions, including borough-wide controls on HMO conversions, shape what’s achievable street by street. BetterLivingSpace checks conservation status, Article 4 restrictions and, where relevant, Dulwich Estate requirements for every Southwark property individually, so nothing we produce is generic and every proposal reflects what actually applies to that address.