Professional RSJ calculations and steel beam design for wall removals, extensions and loft conversions. Stamped reports accepted by Building Control — delivered remotely across the UK.
An RSJ (Rolled Steel Joist) — also commonly called a steel beam or UB (Universal Beam) — is a structural steel section used to carry load across an opening. Whenever a load-bearing wall is removed, a large opening is created, or a structural element needs to span a gap, an RSJ is almost always required to carry the load safely above.
A structural engineer calculates the correct size of RSJ for your specific situation — accounting for the loads above, the span of the opening, and the support conditions at each end. Getting this wrong carries serious structural risk; getting it right means your project passes Building Control first time.
Knocking through between rooms or removing a load-bearing wall to create open-plan space.
Opening up the rear wall of the existing house to connect to a new extension.
Ridge beam, purlin beam and stair opening steel work for loft conversion projects.
Bi-fold doors, wide window openings and structural alterations requiring beam support.
Steel beam design for commercial refurbishments, shop fit-outs and office alterations.
Steel frame elements for garden rooms, annexes and outbuildings.
Our RSJ and steel beam calculation package includes everything required for Building Control approval:
💡 Not sure if your wall is load-bearing? We can assess this as part of the calculation process — just send us your floor plans and we will confirm whether a beam is needed and what size.
RSJ and steel beam calculations start from £500 for a single beam. Projects with multiple beams, complex load paths or additional structural elements are quoted individually — always fixed price, no surprises.
Send us your existing floor plans showing the wall to be removed or opening to be created, along with the proposed layout. If you have architectural drawings already, even better. We will review your project, confirm what is needed and provide a fixed-price quote within 24 hours. The calculation report is typically ready within 2–3 working days.
They refer to the same thing. RSJ (Rolled Steel Joist) is an older term still widely used in the UK. The modern equivalent is a UB (Universal Beam) or UC (Universal Column). Your structural engineer will specify the correct section for your project.
Yes — Building Control will require stamped structural calculations showing that the beam is correctly sized for the loads it carries. A builder cannot specify a beam size without engineering calculations; doing so risks an unsafe structure and a failed Building Control inspection.
In the vast majority of cases, yes. With clear existing and proposed floor plans, we can calculate the correct beam size remotely. We will let you know if a site visit is needed for your specific project.
Typically 2–3 working days from receiving your drawings and confirming the quote. Express delivery is available for urgent projects at an additional fee.
Yes. All our reports are stamped and signed by a UK-qualified structural engineer and are accepted by Building Control authorities across England and Wales.
Submit your drawings online and receive a fixed-price quote within 24 hours. RSJ and steel beam calculations from £500, accepted by Building Control across the UK.
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