How Much Does A Kitchen Extension Cost?

This is usually the first question our customers ask. To help answer it, we’ve created a simple and cutting-edge extension cost calculator. Extension building costs can vary, especially in London. Hopefully, our cost calculator will provide some much-needed clarity.

Our tool makes it easy for you to see exactly what extensions are available to you, and what cost factors are included in your final quote. We’ve also provided 3D models of how your extension would look, bringing your new vision for your home to life.SCROLL TO VIEW ALL

House types

Detached

Semi-detached

End of terrace

Terraced – Flat Back

Terraced – L Shaped

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All example costs:

All estimated costs for house extensions include building work, plumbing, electricity, glazing, external doors and applicable VAT

FLAT ROOF

Small Rear Extension

ESTIMATED COST:

£72,000

FLAT ROOF

Medium / Large Rear Extension

ESTIMATED COST:

£130,000

CROWN ROOF

Medium / Large Rear Extension

ESTIMATED COST:

£139,000

FLAT ROOF

Large Side & Rear Extension

ESTIMATED COST:

£215,000

CROWN ROOF

Large Side & Rear Extension

ESTIMATED COST:

£212,000

GABLE ROOF

Large Wrap Around Extension

ESTIMATED COST:

£118,000

FLAT ROOF

Large Wrap Around Extension

ESTIMATED COST:

£120,000

PITCHED (HIP) ROOF

Large Wrap Around Extension

ESTIMATED COST:

£120,000

GABLE ROOF

Medium Wrap Around Extension

ESTIMATED COST:

£102,000

FLAT ROOF

Medium Wrap Around Extension

ESTIMATED COST:

£103,000

PITCHED (HIP) ROOF

Medium Wrap Around Extension

ESTIMATED COST:

£104,000

GABLE ROOF

Small Wrap Around Extension

ESTIMATED COST:

£90,000

FLAT ROOF

Small Wrap Around Extension

ESTIMATED COST:

£90,000

PITCHED (HIP) ROOF

Small Wrap Around Extension

ESTIMATED COST:

£90,000

FLAT ROOF

Large Side Return

ESTIMATED COST:

£85,000

PITCHED ROOF

Large Side Return

ESTIMATED COST:

£90,000

FLAT ROOF

Medium Side Return

ESTIMATED COST:

£76,000

PITCHED ROOF

Medium Side Return

ESTIMATED COST:

£78,000

FLAT ROOF

Small Side Return

ESTIMATED COST:

£70,000

PITCHED ROOF

Small Side Return

ESTIMATED COST:

£70,000

FLAT ROOF

3m x 3m Rear Extension

ESTIMATED COST:

£72,000

PITCHED ROOF

3m Rear Extension

ESTIMATED COST:

£84,000

GABLE ROOF

3m Rear Extension

ESTIMATED COST:

£87,000

FLAT ROOF

3m Rear Extension

ESTIMATED COST:

£86,000

CROWN ROOF

3m Rear Extension

ESTIMATED COST:

£90,000

As one of London’s leading design and build companies, PLAN A has designed a comprehensive service to simplify the process of planning and constructing your extension. This includes obtaining building regulations approval, planning permission and permitted development rights. We can even set up temporary kitchen facilities allowing homeowners to remain living in the house throughout the build.

We cover many of the London boroughs and some of the home counties, please scroll down for recent examples of house extension projects in your area.