Extensions & Alterations

Do house extensions or alterations need a structural engineer?

What does a structural engineer cost?

Well, it depends on what you need them to do.  As an example, a site visit, inspection, structural calculations and indicative structural drawings suitable for Building Control Authorities approval, with one steel beam (RSJ), could cost you around £300-450 plus VAT.

We know it can seem confusing, but many structural engineers and structural engineering firms will often have a basic list of services that they provide for alterations or extensions at a fixed fee.


A structural engineer will help you to:
  • Determine if you need an architect.
  • Work with your architect, if you need one.
  • Prepare any structural calculations and plans needed by Building Control Authorities.
  • Provide advice to you and your builder.

What is the difference between a structural engineer and an architect?

An architect can help design your extension or alteration. They can make plans for planning permission and building regulations, and they are experts in designing beautiful homes which maximise their value.

A structural engineer is concerned only with the skeleton of your build. They will help you ensure the building is safe, designed to code and built to last. Lastly, they will provide advice and support to your architect and/or builders during the project.

Why choose us


Trust our experience across 3100+ commercial and residential projects.




We’re chartered with The Institution Of Civil Engineers and we are fully insured.



Our pricing and designs are cost efficient. 

What our client’s say

What is the difference between planning permission and building regulations approval?

Planning permission asks your local authority for the go-ahead to begin a construction project. They will look at the environment, your neighbour’s land and the proposed build, to see if it complies with all policies and causes minimal disruption.

A building regulations application is different. It checks to see if your plans comply with national building standards. This looks at the drawings of your build to check for any flaws in the proposed structure. All extensions or structural alterations need Building Control Authority (BCA) approval.

You generally only need planning permission if:

  • The external appearance will change outside of the Permitted Development.
  • If the property is listed.
  • If the property is in a protected area.

A structural engineer can advise you on what kind of permissions you will need, and if your BCA approval will require a full plan or simply a building notice.

Complete the form below to talk with a structural engineer in Leicester, Birmingham, Nottingham, Coventry, Northampton, Milton Keynes or one of the nearby areas.

Get an instant quote!

Use this form to request a quote for structural calculations and drawings required by Building Control Authorities (and your builder) for small house extensions and/or alteration projects. The quote should be ready within 8 hours, during our standard working hours Monday – Friday 9:00 to 17:00, excluding bank holidays. For larger projects, please attach the architectural drawings and we should have the quote ready within 1-2 working days.

We are chartered under the Institution of Civil Engineers, as an insured and fully qualified team of structural engineers.