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 practical cost guide. Extension building costs can vary depending on size, type, and roof configuration.

Our tool makes it easy for you to see what extensions are available to you, and what cost factors are included in your final quote.

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House Type

Select from below options

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

Flat Roof

Small Rear Extension

Estimated Cost:£77,000
Flat roof medium rear extension

Flat Roof

Medium / Large Rear Extension

Estimated Cost:£137,000
Crown roof medium rear extension

Crown Roof

Medium / Large Rear Extension

Estimated Cost:£142,000
Flat roof large side and rear extension

Flat Roof

Large Side & Rear Extension

Estimated Cost:£222,000
Crown roof large side and rear extension

Crown Roof

Large Side & Rear Extension

Estimated Cost:£217,000
Gable roof large wraparound extension

Gable Roof

Large Wrap Around Extension

Estimated Cost:£122,000
Flat roof large wraparound extension

Flat Roof

Large Wrap Around Extension

Estimated Cost:£124,000
Pitched roof large wraparound extension

Pitched (Hip) Roof

Large Wrap Around Extension

Estimated Cost:£123,000
Gable roof medium wraparound extension

Gable Roof

Medium Wrap Around Extension

Estimated Cost:£105,000
Flat roof medium wraparound extension

Flat Roof

Medium Wrap Around Extension

Estimated Cost:£106,000
Pitched roof medium wraparound extension

Pitched (Hip) Roof

Medium Wrap Around Extension

Estimated Cost:£106,000
Gable roof small wraparound extension

Gable Roof

Small Wrap Around Extension

Estimated Cost:£95,000
Flat roof small wraparound extension

Flat Roof

Small Wrap Around Extension

Estimated Cost:£94,000
Pitched roof small wraparound extension

Pitched (Hip) Roof

Small Wrap Around Extension

Estimated Cost:£94,000
Flat roof large side return extension

Flat Roof

Large Side Return

Estimated Cost:£89,000
Pitched roof large side return extension

Pitched Roof

Large Side Return

Estimated Cost:£93,000
Flat roof medium side return extension

Flat Roof

Medium Side Return

Estimated Cost:£79,000
Pitched roof medium side return extension

Pitched Roof

Medium Side Return

Estimated Cost:£80,000
Flat roof small side return extension

Flat Roof

Small Side Return

Estimated Cost:£73,000
Pitched roof small side return extension

Pitched Roof

Small Side Return

Estimated Cost:£73,000
Flat roof 3 by 3 rear extension

Flat Roof

3m x 3m Rear Extension

Estimated Cost:£72,000
Crown roof 3m rear extension

Crown Roof

3m Rear Extension

Estimated Cost:£93,000

As one of London's leading design and build companies, North Star 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 cover many of the London boroughs and home counties and can set up temporary kitchen facilities so homeowners can remain living in the house throughout the build.

Learn More

Need a Precise Quote for
Your Property?

These figures are examples. For an accurate price based on your home and goals, speak with our team.