SECalcs provides Building Control ready structural calculations and drawings for homeowners, architects, and builders across London. We cover extensions, loft conversions, wall removals, and RSJ beam designs. Our focus is on compliant, practical solutions that pass inspection the first time. You’ll get a fixed fee quote fast and your completed calculations within 24 to 72 hours, ready for your builder and Building Control submission.
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.
Every SECalcs design follows British Standards, Eurocodes, and Approved Document Part A. We prepare full calculations, clear drawings, and connection details that Building Control or your Approved Inspector can review easily. Each package is checked before delivery to make sure approval is achieved the first time without delays or extra revisions.
Our calculations are safe, practical, and material efficient. We specify only what is needed, cutting waste and build costs while keeping full structural integrity throughout your project.
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. Every project is signed off by a chartered engineer and supplied with documentation suitable for Building Control and your builder.
We provide full structural calculations and drawings for London homes and small developments. Our engineers design everything from simple RSJ beams to full extensions and basements. Every design is Building Control ready and includes clear load assessments, material specifications, and professional drawings that pass inspection the first time.
We design all types of home extensions, rear, side, and wrap around, plus dormer and hip to gable loft conversions. Each project includes Building Control ready calculations with joists, foundations, and roof structures clearly detailed for your builder.
Our most requested service is RSJ beam design for wall removals and chimney breast alterations. We calculate the correct beam and padstone sizes and provide clear diagrams for Building Control submission, ensuring safety and compliance from start to finish.
We handle retaining walls, underpinning, and temporary works with experience in London ground conditions. Our designs include safe excavation sequences, waterproofing coordination, and party wall notes when required.
We carry out structural inspections, defect reports, and subsidence assessments for homeowners and buyers. Each report is written in plain English with photos, sketches, and practical recommendations for repair or follow up.
We work fast and keep you updated from quote to completion. Most RSJ and wall removal designs are delivered in 24 to 72 hours. Larger projects, like loft conversions and extensions, are usually completed within one to two weeks. Every job starts with a fixed fee quote and clear timeline, so you always know where you stand.
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. We confirm timeframes upfront and stick to them, helping you avoid costly site delays.
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.
We provide structural calculations and drawings across all London boroughs for homeowners, architects, and builders. Our engineers understand local property types and work closely with Building Control teams across Greater London. Every project receives the same fast turnaround, fixed fee quote, and compliant design package.
Extensions, loft conversions, and wall removals with submissions ready for Building Control in Barnet, Haringey, and Enfield.
Open-plan refurbishments, kitchen extensions, lofts, and RSJ installations. Calculations prepared for Building Control in Ealing, Hounslow, and Hammersmith.
Alterations, lofts, and extensions for terraces and new developments, prepared for quick approval by local Building Control.
RSJ designs, extensions, and side returns for period homes, aligned with Building Control in Wandsworth, Lambeth, and Croydon.
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.
South West London
South West London
North London
North London
West London
Choosing the right engineer saves time and money. Rejected designs or incorrect beam sizes can cause costly site delays. Every SECalcs project is reviewed by a Chartered Structural Engineer to make sure your Building Control or Approved Inspector submission is accepted first time.
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.
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. That includes wall removals, RSJ installations, or chimney breast alterations. Building Control requires professional calculations and drawings before approval.
Simple RSJ or wall removal designs are usually completed in 24 to 72 hours. Extensions and loft conversions take around one week, while larger projects such as basements can take up to two weeks. We confirm exact timeframes when we quote.
Yes. Every design we produce is Building Control ready and fully compliant with British Standards and Part A. We prepare clear calculations, drawings, and connection details that pass inspection the first time.
We just need your property address, drawings or sketches, and a short description of the work. Photos help if no plans are available. You’ll receive a fixed-fee quote, usually within a few hours.
Wall removal calculations start from £195. Extensions typically start from £450 and loft conversions from £550. All fees are fixed upfront with no hidden extras, so you always know your total cost before work begins.
Choose an engineer experienced with domestic projects and Building Control submissions. Look for clear fixed-fee quotes, reliable communication, and insurance. Ask about previous projects in your area.
Yes. All SECalcs engineers are qualified members of professional bodies and our practice holds full Professional Indemnity and Public Liability Insurance. Copies are available on request.
Wall removal calculations start from £195, while full extension or loft conversion designs typically range from £450–£550 depending on complexity. Both services include complete Building Control-ready drawings and calculations.
Ready to start? Upload your drawings, sketches, or photos and we’ll send you a fixed-fee quote within hours. Most designs are completed in 24 to 72 hours with Building Control-ready calculations and drawings. No hidden costs, no waiting around — just fast, reliable structural design from engineers who know London.
Send your drawings today for a free quote!
