How Much Does a Structural Engineer Cost in the UK?
A structural engineer is required for any building work that affects the structure of a building — including installing steel beams, removing load-bearing walls, building extensions, converting lofts, and underpinning foundations. For most straightforward residential projects, structural engineering fees are modest, but they are an essential investment to ensure safety and compliance with building regulations.
Typical Cost (UK, 2026)
All costs are indicative estimates. Obtain at least 3 quotes from qualified builders. Prices exclude VAT (20%).
Factors Affecting the Cost
Scope of work
A single beam calculation costs far less than a full structural design package for an extension with multiple openings.
Location
Engineers in London and the South East charge more than those in other regions. Expect a 20–30% premium in London.
Complexity
A basement, underpinning, or complex multi-storey extension requires more detailed calculations and drawings than a simple loft conversion.
Report format
A simple letter confirming beam sizes costs less than a full set of structural drawings required for building regulations.
Cost Breakdown
| Item | Basic | Mid-range | High-end |
|---|---|---|---|
| RSJ / steel beam calculation (letter/report) | £300 | £450 | £650 |
| Loft conversion structural design | £500 | £800 | £1,200 |
| Extension structural design (full drawings) | £800 | £1,200 | £1,800 |
| Basement / underpinning structural design | £1,500 | £2,500 | £5,000 |
| Structural survey / assessment of existing building | £400 | £700 | £1,200 |
Costs are indicative and exclude VAT. Regional variations apply.
Typical Timeline
Beam calculations: 3–7 working days; full structural design: 2–4 weeks
Frequently Asked Questions
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