As a specialist structural engineer London practice, SECalcs provides Building Control ready structural calculations and drawings for homeowners, architects, and builders. We work across north London, south London, east London and west London to deliver compliant, practical solutions that pass inspection the first time. You’ll get a fixed fee quote fast and your completed structural calculations within 24 to 72 hours.
Fast, clear structural calculations and drawings for domestic projects across the capital.
We act as the primary structural engineer in London for homeowners, landlords, architects, and builders.
Our focus is strictly on domestic projects and small developments. We don't overcomplicate things—we provide exactly what you need to get your project built and approved by Building Control without delays.
We are experienced structural engineers trusted across London for fast, Building Control ready designs. Our service is professional, reliable, and transparent. Every client gets a fixed fee quote before work starts with no hidden extras.
We specialise in home extensions, loft conversions, RSJ designs, and internal wall removals. Our engineers support homeowners, architects, and builders with clear, buildable calculations that make construction simple and keep Building Control in London straightforward.
With over two decades of experience in London structural engineering, we know the local housing stock inside out—from Victorian terraces to modern builds.
Every SECalcs design follows British Standards, Eurocodes, and guidance from the Planning Portal. We prepare full calculations, clear drawings, and connection details that Building Control or your Approved Inspector can review easily.
SECalcs engineers are members of recognised professional bodies such as The Institution of Structural Engineers (IStructE) and the Engineering Council. Our practice carries full Professional Indemnity and Public Liability Insurance for your peace of mind.
OUTSTANDING
Based on 150 reviews
Recent comments from clients across the UK.
Amelia Wright
3 months ago
SECalcs explained everything in plain English and turned our extension around quickly. Building Control asked one question which they handled the same day. Couldn’t have been easier.
Daniel Foster
5 months ago
Professional from start to finish. Clear drawings, accurate calcs, and a fair fixed fee. Our builder commented on how tidy the pack was.
Priya Shah
1 year ago
Needed steel design for a through-lounge wall removal. They checked the foundations, sized the RSJ, and provided padstone details. Building Control approval came back without any fuss.
Hannah McBride
7 months ago
We had an urgent loft conversion that needed sign-off. SECalcs delivered on time and answered the inspector’s query the same morning. Highly recommend.
Avtar Singh
2 months ago
SECalcs designed steels for our rear extension and knocked-through kitchen. Clear markups, prompt responses, and Building Control signed off first time.
As a leading structural engineer London practice, we specialise in domestic projects that require fast, accurate attention.
We provide full structural calculations and drawings for London homes and small developments. Our engineers design everything from simple steel beam calculation London packages to full extensions and basements.
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. If you need a structural engineer for loft conversion London projects, we design the ridge beam, floor steels and load paths so your builder has a clear set of drawings to follow.
We provide expert RSJ design London services for chimney breasts and internal alterations. Perfect for any load bearing wall removal London project.
We handle retaining walls, underpinning, and temporary works with experience in London ground conditions. Our designs include safe excavation sequences and waterproofing coordination. Many clients come to us when they need a structural engineer for retaining wall London schemes, from small garden walls to full basement walls.
We carry out structural inspections, defect reports, and subsidence assessments for homeowners and buyers. Each report is written in plain English with photos.
We work fast and keep you updated from quote to completion. Most RSJ and wall removal designs are delivered in 24 to 72 hours.
Our process is quick but careful. Simple steel beam designs are finished in 24 to 72 hours, while more detailed projects take only a few days longer.
Send your plans: email drawings, sketches, or photos with a short description.
Receive your quote: we reply with a fixed fee and timeframe, usually the same day.
Design and review: our engineers prepare the calculations and drawings for your approval.
Submit for approval: final files are ready to send straight to Building Control.
Transparent, fixed-fee pricing. No hidden hourly rates.
For every project, we confirm the total structural engineer London cost as a simple fixed fee before starting.
Whether you need full extension drawings or just need to check structural engineer costs for RSJ calculation, you will know exactly what you are paying upfront.
We provide structural calculations and drawings across all London boroughs for homeowners, architects, and builders.
Extensions, loft conversions, and wall removals with submissions ready for Building Control. We regularly submit calculations and drawings to Barnet Council Building Control.
Open-plan refurbishments, kitchen extensions, lofts, and RSJ installations.
Alterations, lofts, and extensions for terraces and new developments.
RSJ designs, extensions, and side returns for period homes. For projects in South West London we regularly submit our calculations to Wandsworth Council Building Control.
We understand timber floors in Victorian terraces and concrete frames in newer blocks. Every calculation matches local methods and Building Control expectations.
We’ve supported hundreds of London homeowners and architects with fast, compliant structural designs.
SECalcs delivered my wall removal calculations within two days and Building Control passed them first time.
Clear drawings and quick responses made our loft conversion simple.
Each project receives the same care and clear communication from first enquiry to approval.
Choosing the right engineer saves time and money. Rejected designs or incorrect beam sizes can cause costly site delays.
A chartered engineer checks each job before delivery for code compliance and clarity.
Calculations, specs, and drawings packaged for direct submission without rework.
We specify only what is needed and make it clear for your builder on site.
As a chartered structural engineer London practice, we bring over 20 years of experience in London residential engineering to your project. We understand the specific challenges of local housing stock, from Victorian terraces to modern builds.
We provide comprehensive structural calculations London packages backed by full Professional Indemnity and Public Liability insurance. Our team has extensive experience working with London councils and Building Control officers to ensure your project gets approved smoothly.
Here are some common questions we’re asked about structural design and Building Control in London.
You’ll need a structural engineer for extensions, loft conversions, or any work that changes your home’s structure.
Look for a chartered professional who holds full Professional Indemnity Insurance and has specific experience with London housing stock, such as Victorian terraces or basement conversions. A reputable structural engineer in London should always provide fixed-fee quotes and clear, Building Control-ready drawings.
Simple RSJ or wall removal designs are usually completed in 24 to 72 hours. Extensions and loft conversions take around one week.
Yes. Every design we produce is Building Control ready and fully compliant with British Standards and Part A. We regularly work with local authorities such as Croydon Council Building Control for extensions, lofts, and wall removals.
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.
We just need your property address, drawings or sketches, and a short description of the work.
Wall removal and RSJ calculations in London start from around £250–£350. Extensions typically start from £450 and loft conversions from £550. All structural engineer London costs are fixed upfront before we 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 engineers who know London.
