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Structural Engineering Calculations & RSJ Beam Sizing
Building control-ready structural calculations for beam sizing, load-bearing wall removals and structural alterations. Prepared to Eurocode and British Standard methods, with every limit-state check shown in full. Fixed fee from £550.
Structural Calculations for Every Common Alteration
If you are removing a load-bearing wall, taking out a chimney breast or forming a new opening, your building control body will require structural calculations demonstrating that the remaining structure is safe and adequately supported. We prepare those calculations to Eurocode and British Standard methods, presented in the format building control inspectors expect to see.
Every calculation pack sets out the loading, the load path, the member being designed and the full set of limit-state checks — shear, bending, buckling and deflection — with the utilisation percentage against each. Nothing is hidden behind a summary line, so your inspector can follow the reasoning and sign it off without queries.
RSJ & Steel Beam Sizing
Universal beam and universal column sizing to BS EN 1993-1-1 (Eurocode 3), with shear, bending moment, lateral-torsional buckling and deflection checks.
Load-Bearing Wall Removals
Knock-throughs and new openings, including padstone sizing, bearing pressures and the buttressing or restraint required either side.
Chimney Breast Removals
Ground, first floor or attic-level removals, with gallows bracket or beam support options and the loading from the retained stack above.
Timber Joist & Rafter Design
Floor and flat roof joists to BS 5268-2, with depth and load-sharing modification factors and clear span verification.
Foundations & Padstones
Strip and pad foundation sizing, precast lintels over service runs, and Class B engineering brick pier design.
Loft & Boiler Installations
Additional loadings from loft conversions, water tanks and boiler installations checked against existing structure.
Prepared to Eurocode and British Standard Methods
Structural calculations submitted to UK building control need to demonstrate compliance with Approved Document A (Structure). We work to the current Eurocode suite and, where permissible-stress design remains appropriate for timber, to BS 5268-2:2002.
Each pack is issued as a clear, readable document rather than a raw software dump — loading assumptions stated, reactions tabulated, shear force and bending moment diagrams plotted, and every utilisation figure shown against its resistance.
- checkBS EN 1993-1-1 / NA:2008 — Eurocode 3, steel structures — universal beams and columns
- checkBS EN 1995-1-1 — Eurocode 5, timber structures where applicable
- checkBS 5268-2:2002 — permissible stress design for timber joists and rafters
- checkApproved Document A — Structure — the building regulation your inspector assesses against
- checkBS EN 1990 / 1991 — basis of structural design and actions on structures
A Complete, Inspector-Ready Calculation Pack
Your calculation pack arrives as a single PDF, laid out so a building control officer can work through it in order. Where the design affects the drawings, we annotate the structural member sizes directly onto the plan so the builder on site knows precisely what to install.
Where more than one solution is viable — a single beam against a box frame, or steel against twin Catnic lintels — we set out both options with their respective implications, so you and your builder can choose on cost and buildability rather than being handed a single fixed answer.
- checkDesign summary — every limit-state check with resistance, applied action and utilisation percentage
- checkLoading schedule — permanent and variable actions, self-weight and load path traced to supports
- checkReactions — unfactored and factored support reactions at each bearing
- checkDiagrams — shear force and bending moment diagrams plotted against design resistances
- checkSection details — member size, steel grade, dimensions and mass per metre
- checkConnection detail — padstones, bearing lengths, strapping and restraint requirements
Often Faster Than Our Two-Week Standard
Standalone structural calculations are usually quicker than a full drawing package. Straightforward beam sizing and chimney breast removals are frequently turned around in a matter of days, which matters when a builder is already on site and waiting to open up.
If you are working to a tight programme, say so when you enquire and we will tell you honestly what we can achieve rather than quoting a date we cannot hold.
Structural Calculations — £550 Fixed Fee
One fixed price covering the calculation pack, member sizing, connection details and revisions. Combine with planning drawings in our Full Package at £1,650 and save against booking each separately.
Structural Calculations — Frequently Asked Questions
How much do structural calculations cost?
Our structural calculations are a fixed £550, covering the full calculation pack, member sizing, connection details and revisions. If you also need planning drawings, the Full Package at £1,650 combines both and works out cheaper than booking each separately.
What is an RSJ and how do you size one?
RSJ stands for Rolled Steel Joist, though most modern residential work uses Universal Beams. Sizing involves establishing the loads carried, calculating the resulting shear force and bending moment, then selecting a section whose resistance exceeds the applied actions across every limit state — including lateral-torsional buckling and deflection, which frequently govern in domestic spans.
Do I need structural calculations to remove a load-bearing wall?
Yes. Removing or forming an opening in a load-bearing wall is notifiable work under the Building Regulations, and building control will require calculations demonstrating the replacement beam and its bearings are adequate. This applies whether you use a full plans application or the building notice route.
Will building control accept your calculations?
Yes. Our calculations are prepared to Eurocode and British Standard methods and set out in the format inspectors expect, with every limit-state check shown in full. If your building control body raises a query, we respond and revise at no extra cost.
Can you do calculations for a chimney breast removal?
Yes, this is one of our most common jobs. We cover ground floor, first floor and attic-level removals, and will set out the support options — gallows brackets or a beam — along with the loading from the retained stack above.
Do you need to visit the property?
No. We work entirely online across the UK. We send you a measuring kit with a laser measurer and a guide showing which dimensions and photographs we need, and prepare the calculations from what you send back.
How quickly can you turn calculations around?
Standalone calculations are often faster than our two-week standard, with straightforward beam sizing and chimney breast removals frequently completed in a matter of days. Tell us your deadline when you enquire and we will confirm honestly what is achievable.
Do you provide the beam and padstone details for my builder?
Yes. Alongside the calculations we provide the member size, steel grade, bearing lengths, padstone dimensions and any strapping or restraint requirements, annotated onto the drawings where relevant so your builder knows exactly what to install.
Ready to Get Started?
Tell us about your project and we'll come back within 24 hours with a fixed price and a confirmed two-week delivery slot. No site visit required — we work remotely right across the UK.
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