Maximum extension sizes without planning permission — applied to Birmingham City Council in the West Midlands. With intensive Gateway 3 sign-off and HRB oversight and an average build cost of £2100/sqm, the deal arithmetic for permitted Development Extensions here is distinct from neighbouring boroughs.
Heads up: Birmingham City Council operates Article 4 directions, so permitted Development Extensions that would normally be permitted development will likely require a full planning application here. Build that into your timeline and risk model.
Run any West Midlands listing through Scapely to get a property-specific build cost, council objection-risk score and the AI Objection Risk Analyzer overlay applied to Birmingham City Council's policy environment.
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