
How much does a house extension cost?
Below are a collection of house extension prices. We haven’t covered double story, wrap around and loft conversions, but, if you send in your enquiry, we can provide build costs for any project. We can also obtain a fixed build cost from reliable local builders on your behalf after the final design is complete. Contact us so we can explain more
All example costs:
All estimated costs for house extensions cover building work, architectural plans and planning submission.
All example costs:
All estimated House Extension Costs cover building work, plumbing, electrical work, glazing, external doors, architectural plans, structural engineering, and planning submission.
Detached House Extensions

Small Flat Roof Extension
Size 3m x 3m
Estimated costs:
£22,995+vat
Architectural Plans & Structural Engineering Included

Large Flat Roof Extension
Size 9m x 3m
Estimated costs:
£49,995+vat
Architectural Plans & Structural Engineering Included

Gabled Roof Extension
Size 4m x 6m
Estimated costs:
£44,995+vat
Architectural Plans & Structural Engineering Included

Pitched Roof Extension
Size 7m x 3m
Estimated costs:
£39,995+vat
Architectural Plans & Structural Engineering Included
Semi-Detached House Extensions

Small Flat Roof Extension
Size 4m x 3m
Estimated costs:
£26,995+vat
Architectural Plans & Structural Engineering Included

Large Flat Roof Extension
Size 8m x 3m
Estimated costs:
£45,995+vat
Architectural Plans & Structural Engineering Included

Gabled Roof Extension
Size 7m x 3m
Estimated costs:
£39,995+vat
Architectural Plans & Structural Engineering Included

Pitched Roof Extension
Size 5m x 3m
Estimated costs:
£29,995+vat
Architectural Plans & Structural Engineering Included
Terrace House Extensions

Small Flat Roof Extension
Size 3m x 3m
Estimated costs:
£23,995+vat
Architectural Plans & Structural Engineering Included

Large Flat Roof Extension
Size 6m x 4m
Estimated costs:
£44,995+vat
Architectural Plans & Structural Engineering Included

Gabled Roof Extension
Size 5m x 4m
Estimated costs:
£41,995+vat
Architectural Plans & Structural Engineering Included

Pitched Roof Extension
Size 6m x 3.5m
Estimated costs:
£43,995+vat
Architectural Plans & Structural Engineering Included
Bungalow House Extensions

Small Flat Roof Extension
Size 4m x 3.5m
Estimated costs:
£29,995+vat
Architectural Plans & Structural Engineering Included

Large Flat Roof Extension
Size 9m x 4.5m
Estimated costs:
£71,875+vat
Architectural Plans & Structural Engineering Included

Gabled Roof Extension
Size 6m x 4m
Estimated costs:
£48,775+vat
Architectural Plans & Structural Engineering Included

Pitched Roof Extension
Size 7m x 3.5m
Estimated costs:
£47,995+vat
Architectural Plans & Structural Engineering Included
For more information on the design and build process please call our team or complete our enquiry form
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