ePrivacy and GPDR Cookie Consent by Cookie Consent Extension Cost Calculator | Resi

Construction cost calculator

Let's estimate the
construction costs!

Answer a few quick questions below and we'll estimate the costs involved from our extensive experience working with projects like yours

Talk simple

Have a question for our team?

Construction cost estimator

The three main factors are extension type, the size and your location

Which part of the property are you looking to extend?

Select a part of your house to choose an extension type









Two storey

Two Storey

How big is the area being changed in square metres?

The total of the new area being added, and existing area impacted

Select an extension type above to see size options

A few details about you...

Already Registered?

Have a question?

Fill in a few details and we’ll get back to you right away.


Phone: +44 208 068 4811 | Email: advice@resi.co.uk

Resi Design Ltd. trading as 'Resi' | Company No: 10471125

We are proud to employ architects registered with the Architects Registration Board and were awarded the mark for The Mayor's Good Work Standard for fair pay & conditions, wellbeing, skills, progression, diversity and recruitment.

Resi Finance Ltd is an appointed representative of Mortgage Advice Bureau Limited and Mortgage Advice Bureau (Derby) Limited who are authorised and regulated by the Financial Conduct Authority. Resi Finance Ltd. Registered Office: International House Canterbury Crescent, Floor 4, London, England, SW9 7QE. Registered in England Number: 12327535