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What type of extension?
Different types have different base costs per m².
🏠
Single-Storey Rear
£1,800–£2,400/m² · most popular
↔️
Single-Storey Side Return
£1,900–£2,500/m² · terraced infill
🏘
Double-Storey
£2,000–£2,750/m² · best ROI
🔲
Wraparound
£2,100–£2,900/m² · rear + side
🔨
Loft Conversion
£1,300–£1,900/m² · no planning (usually)
🚪
Porch / Small Front
£1,500–£2,100/m² · budget option
