Rear Extensions: Max 40mІ total (cumulative). Terraced/Semi: Max 12mІ at first-floor level. Detached: Max 20mІ at first-floor level. Common Domestic Extensions Garden Structures: Sheds/Garages must be behind the front building line (3m-4m height limits). Boundary Walls: Max 1.2m (Front) or 2.0m (Side/Rear). Solar Panels & Renewable Energy: Solar panels on the roof of a house or within its curtilage generally fall under exempted development, subject to specific limits on surface area and placement. Interior Works: Renovations that do not alter the external appearance.