Extensions & Loft Conversions
We act as your specialist loft conversion structural engineer London partner. We also provide complete home extension structural design London drawings that are fully Building Control ready.
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Greater London & Surrounding Areas
Chartered Structural Engineers London
SECalcs is a specialist team of structural engineers London homeowners and builders rely on for fast, Building Control-ready structural engineering London calculations and drawings. As experienced London structural engineers, we work across north London, south London, east London and west London to deliver compliant, practical solutions.
You will get a fixed-fee quote fast and completed structural calculations London within 24 to 72 hours. Among the structural engineering companies London clients can choose from, we focus exclusively on residential work.
With over two decades of experience, we know the local housing stock inside out – from Victorian terraces to modern builds. Every client gets a fixed-fee quote before work starts with no hidden extras.
Common London Projects
Project snapshots and common jobs we specialize in:
- ✓RSJ beams for kitchen wall removals
- ✓Steel ridge beams for loft bedrooms
- ✓Single-storey rear extensions
- ✓Structural inspections and reports
- ✓Retaining walls and basements
Structural calculations London – costs and fees
Transparent, fixed-fee pricing for structural calculations London projects. No hidden hourly rates.
| Service | Typical Fee (London 2026) | What Is Included |
|---|---|---|
| RSJ beams London / Wall Removal | £250 to £350 | Beam sizing, padstone design, masonry checks |
| Structural Alterations London | £300 to £900 | Chimney breasts, new openings, floor changes |
| Rear / Side extension design | £450 to £750 | Foundations, masonry checks and steelwork |
| Loft conversion design | from £550 | Ridge beam, floor joists, dormer supports |
| Structural inspections | £350 to £650 | Cracks, subsidence, clay movement, pre-purchase |
| Basement / Retaining wall | Fixed fee quote | Underpinning, temporary works, retaining structures |
Structural engineering services London – calculations and drawings
Fast, clear structural engineering services London homeowners and architects need – fixed fees, 24–72 hour turnaround across Greater London.
RSJ Beams London and Load Bearing Wall Removal
We design RSJ beams London homeowners need for kitchen wall removals, through-lounges and rear openings. Complete load bearing wall removal London service with sizing and padstone details.
Basements & New Builds
We handle retaining walls, underpinning, and temporary works with experience in London ground conditions.
Structural Reports & Surveys
We carry out structural inspections, defect reports, and subsidence assessments for homeowners and buyers.
Residential and Domestic Expertise
We specialise in home extensions, loft conversions, RSJ designs, and internal wall removals across all 32 boroughs.
Building Control Compliance
Every SECalcs design follows British Standards, Eurocodes, and guidance from the Planning Portal. Building Control ready.
Why Choose Our Structural Engineering London Practice
We are experienced structural engineers trusted across London for fast, Building Control-ready designs. Getting it right first time saves costly site delays.
Residential Expertise
Among the structural engineering companies London homeowners and builders can choose from, SECalcs is one of the few structural engineering firms London-wide that specialises exclusively in residential work.
Established 20+ Years
As a structural engineering consultancy London clients trust for fast turnaround, we bring deep knowledge of London residential engineering to your project.
Building Control Compliance
Calculations, specs, and drawings packaged for direct submission without rework. Accepted by Building Control across all 32 boroughs.
Fast Turnaround
Simple steel beam designs are finished in 24 to 72 hours, while more detailed structural calculations London packages take only a few days longer.
What You Get in Your Pack
A clear set of structural calculations helps your project move smoothly through Building Control. Our packs are straightforward for both inspectors and builders.
Structural Calculation Pack:
- ✓RSJ and steel beam design
- ✓Floor and roof calculations
- ✓Foundation checks for extensions
- ✓Clear sketches showing each item
- ✓Timber design for joists/rafters
- ✓Padstones and bearing details
Building Control:
We prepare full calculation packs and drawings that your council can review easily, submitting work across London boroughs such as Barnet, Wandsworth and Croydon.
Speed & Process
We work fast and keep you updated from quote to completion.
1
Send your plans
Email drawings, sketches, or photos with a short description.
2
Receive your quote
We reply with a fixed fee and timeframe, usually the same day.
3
Design and review
Our engineers prepare the calculations and drawings for your approval.
4
Submit for approval
Final files are ready to send straight to Building Control.
What Homeowners Say About SECalcs
Recent comments from clients across London.
★★★★★
"SECalcs explained everything in plain English and turned our extension around quickly. Building Control asked one question which they handled the same day."
Amelia Wright
★★★★★
"Needed steel design for a through-lounge wall removal. Checked the foundations, sized the RSJ, and provided padstone details. Building Control approval came back without any fuss."
Priya Shah
★★★★★
"SECalcs delivered my wall removal calculations within two days and Building Control passed them first time."
Sarah, Wandsworth
Areas We Cover Across Greater London
We provide structural calculations London-wide and drawings for all 32 London boroughs.
●Structural Engineer North London
●Barnet
●Haringey
●Enfield
●Structural Engineer West London
●Ealing
●Hounslow
●Hammersmith
●East London
●Hackney
●Tower Hamlets
●Newham
●Structural Engineer South London
●Structural Engineer South East London
●Wandsworth
●Lambeth
●Croydon
●Greenwich
●Lewisham
●Southwark
●Bromley
●Greater London
Structural Engineers London – Common Questions
Common questions about structural design, Building Control and fees from our structural engineer London clients.
Do I need a structural engineer for my project?
You will need a structural engineer for extensions, loft conversions, or any work that changes your home’s structure. Most work involving steels, new beams or load path changes requires formal structural calculations London Building Control can approve.
How do I choose a structural engineer in London?
Look for a chartered professional who holds full Professional Indemnity Insurance and has specific experience with London housing stock. Among the structural engineering companies London clients can choose from, those with a residential specialism will understand Victorian terraces, basement conversions and loft structures better than a generalist firm. A reputable structural engineer in London should always provide fixed-fee quotes and clear, Building Control-ready drawings.
How long do calculations take?
Simple RSJ or wall removal designs are usually completed in 24 to 72 hours. Extensions and loft conversions take around one week. Structural calculations London turnaround depends on how much information we have from the start – clear drawings and photos speed things up significantly.
Will SECalcs help with Building Regulations approval?
Yes. Every design we produce is Building Control ready and fully compliant with British Standards and Part A. We prepare full calculation packs and drawings that your council can review easily, and we regularly submit work across London boroughs such as Barnet, Wandsworth and Croydon.
What do you need for a quote?
We just need your property address, drawings or sketches, and a short description of the work. Clear photos of the existing structure help us confirm scope and fix the fee faster.
How much does a structural engineer London cost?
Wall removal and RSJ beams London start from around £250–£350. Extensions typically start from £450 and loft conversions from £550. Structural inspections run £350–£650. All structural engineer London costs are fixed upfront before we start – no hidden hourly rates.
How much do structural calculations London cost?
Structural calculations London fees depend on project type. Typical fixed fees are: RSJ beams London £250–£350 | Loft conversion structural calculations London from £550 | Rear or side extension £450–£750 | Structural inspection £350–£650. All structural calculations London prices are fixed upfront – you confirm the fee before we start and there are no hourly charges.
Do you work as a structural engineer north London and west London?
Yes. We cover all quadrants of Greater London. As a structural engineer north London practice we regularly work in Barnet, Haringey, Enfield, Islington and Camden. As a structural engineer west London practice we cover Ealing, Hounslow, Hammersmith, Chiswick and Richmond. We are also a structural engineer south London specialist covering Wandsworth, Lambeth, Merton and Bromley, and a structural engineer south east London practice covering Greenwich, Lewisham and Southwark.
Are you one of the structural engineering companies London recommends?
SECalcs is one of the most reviewed residential structural engineering companies London homeowners use for domestic projects. Unlike larger structural engineering firms London-wide that handle commercial and infrastructure work, we focus exclusively on homes – which means faster turnaround, clearer pricing and engineers who know residential construction inside out. As a specialist structural engineering consultancy London clients return to, we carry full Professional Indemnity Insurance and our engineers hold chartered status.
Ready to Start?
Most designs are completed in 24 to 72 hours with Building Control-ready calculations and drawings. No hidden costs and no waiting around – just fast, reliable structural design from structural engineers London who know the local housing stock.
Phone
Email
Response Time
Within one working day for most projects.
Service Area
Greater London, including North, South, East, West, and South East London boroughs.
Many London jobs are designed from drawings and photos. If a site visit is needed we explain why and add it to the quote upfront.
Ready to Start?
Fixed-fee RSJ beams and structural calculations from £250. Building Control-ready in 24 to 72 hours. Call 07359 267907 or fill in the form for a same-day reply.
- Head Office: Corwell Lane, Uxbridge, England, UB8 3DE.
- 07359 267907
- info@structuralengineercalcs.com
- Company No: 12653163