Free tool
How much will yourextension cost?
Enter your house width and how far you want to extend. Get an area-specific estimate with permitted development guidance and the hidden costs nobody tells you about.
6m × 4m = 24m²
For permitted development guidance
Estimated cost
Excluding VAT. VAT estimate: £11477 – £15272
Important note
These are estimates, not quotes.
Every project is different. These figures are based on typical costs in the Dorset area and should be used as a starting point, not a final budget. For an accurate assessment, start with our £250 Design Discovery — we will give you a realistic cost breakdown tailored to your specific property.
Want an accurate quote, not an estimate?
Start with professional plans from £250. We will give you a realistic cost breakdown for your specific project.
Every plan drawn by qualified drafters in Poole, Dorset
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