How Much Does a Structural Engineer Cost in London?
If you're planning a home project — a loft conversion, rear extension, or knocking through a load-bearing wall — one of the first questions is: how much will a structural engineer cost?
At SBS Structural and Architectural Design, we believe in transparent, fixed pricing. Here's a straightforward breakdown of what structural engineering services typically cost in London in 2026.
Typical Structural Engineer Fees in London
| Service | Typical Cost Range | |---|---| | Loft conversion calculations | £800 – £1,500 | | Rear/side extension calculations | £800 – £1,800 | | Steel beam calculation (single beam) | £400 – £800 | | Load-bearing wall removal | £400 – £900 | | Chimney breast removal | £400 – £800 | | Structural survey | £400 – £800 | | Full structural package (drawings + calcs) | £1,200 – £3,000 | | Retrospective Building Regs application | £600 – £1,200 |
These are guide prices. The actual cost depends on the complexity of your project, the size of your property, and whether you need drawings as well as calculations.
Real Project Examples from SBS
To give you a clearer picture, here's what actual recent projects cost our clients:
Victorian terrace in Ilford — rear extension + wall removal: A homeowner wanted a 4m rear extension with the kitchen wall knocked through to create open-plan living. We provided full structural calculations, steel beam design for the wall removal, foundation details, and Building Control drawings. Total fee: £1,400. Building Control approved first time, builder started 6 days after we were instructed.
1930s semi in East Ham — loft conversion: Full dormer loft conversion including new floor joists, ridge beam, staircase opening trimmer, and two dormer support steels. This was a more complex job because the existing party wall needed checking against the increased loading. Total fee: £1,200. Turnaround was 5 working days.
Edwardian mid-terrace in Stratford — chimney breast removal: Ground floor chimney breast removal with gallows brackets to support the breast on the first floor. Straightforward job once we'd confirmed the stack condition. Total fee: £450. Done in 3 working days.
The common thread: every project was fixed-price, quoted upfront, with no surprises.
What's Included in Structural Engineer Fees?
When you hire a structural engineer, you're paying for:
- Site visit — we inspect your property and take measurements
- Structural calculations — the engineering analysis that proves the design is safe
- Structural drawings — detailed plans your builder works from
- Building Control submission — we prepare everything Building Control needs to approve the work
- Revisions — if Building Control has queries, we handle them
At SBS, our quotes are fixed. The price we quote is the price you pay. No hourly rates, no surprises.
What Affects the Cost?
Project Complexity
A simple steel beam for a knocked-through wall costs less than a full loft conversion with dormers, new staircases, and multiple structural elements.
Location
London structural engineers tend to charge more than those outside the M25 — but you also get local knowledge of London borough Building Control requirements, party wall considerations, and typical property types.
Turnaround Time
Standard turnaround is around 5–7 working days at SBS. If you need drawings urgently, our express 48-hour service is available for an additional fee.
Drawings vs Calculations Only
Some projects only need calculations (e.g. a single steel beam). Others need full structural drawings. Drawings cost more but give your builder everything they need.
How SBS Keeps Costs Down
We specialise in residential structural engineering — that's all we do. This focus means:
- We work efficiently because we design loft conversions, extensions and steel beams every day
- We don't charge for a lengthy "scoping phase" — we know what's needed
- Fixed pricing means no clock-watching and no bill shock
- 1-week turnaround keeps your project on track and avoids costly delays
When Do You Need a Structural Engineer?
You'll need a structural engineer for any work that affects the structure of your home:
- Loft conversions — steel beams, floor strengthening, staircase openings
- Extensions — foundations, steelwork, connections to existing structure
- Removing a wall — if it's load-bearing, you need a steel beam designed
- Chimney breast removal — gallows brackets or steel beams to support the stack above
- Subsidence or cracks — a structural survey identifies the cause and solution
- Buying a property — a structural survey tells you what you're really buying
Do I Need a Structural Engineer or an Architect?
Both do different things:
- An architect designs the layout and appearance of your project
- A structural engineer designs the hidden structure that holds everything up — beams, foundations, load paths
For many residential projects, you need both. Some homeowners start with an architect's drawings and then come to us for the structural design. Others come to us first if they already know what they want (e.g. "I want to remove this wall").
Get a Free Quote
At SBS Structural and Architectural Design, we offer free consultations for homeowners across London, Essex and Kent. We'll discuss your project, explain what's needed, and give you a clear fixed price.
- Phone: +44 7401 650 600
- Email: sbs.structures@gmail.com
- Office: 61 Cranbrook Road, Ilford, IG1 4PG
We cover over 70 locations including Ilford, East London, Stratford, Romford, Barking, Greenwich, and beyond.
