Steel-framed building design
A steel frame gives long spans, quick erection and a clear route for future change. We design steel-framed commercial and industrial buildings from the primary members down to the connections and foundations, for clients across the UK.
Why choose a steel frame over concrete or timber?
Steel gives long clear spans, a fast erection programme and easy future alteration, which suits most commercial and industrial buildings. We compare the options for your project and recommend the frame that carries the loads at the lowest overall cost and programme.
Choosing and sizing the frame
Steel suits buildings that need long spans, fast programme or the ability to change use later, and the first decision is the framing system. A simple braced frame with beams and columns suits offices and multi-storey work, a portal frame suits single-storey sheds, and a mix of the two suits buildings with a workshop and offices under one roof. We choose the arrangement that carries the loads with the least steel and the simplest connections, then size the members to BS EN 1993 and its UK National Annex.
Sizing steel is a balance of strength, deflection and stability. We check each beam for bending, shear and lateral-torsional buckling, each column for combined axial load and moment, and the whole frame for sway. Universal beams and columns cover most cases, with cellular or fabricated sections where long spans or services routes justify them. We keep an eye on tonnage throughout, because the frame is usually the single biggest structural cost.
Connections and stability
The connections are where a steel frame is made or lost. We decide early whether the frame is braced, with simple pinned connections and separate bracing or cores taking the horizontal load, or whether it relies on moment connections to stay upright, because that decision runs through every joint and every column. Simple connections are cheaper to fabricate and erect, so we use bracing wherever the architecture allows, and reserve moment frames for the bays where bracing cannot go.
We design the connection details, end plates, fin plates, base plates, splices and bracing gussets, to carry the real forces and to be buildable, then present them so the steelwork contractor can fabricate without a stream of queries. Base plates and holding-down bolts are detailed for the column reactions including any uplift, and we coordinate the base details with the foundation design so the two halves of the job meet correctly on site.
Fire, corrosion and coordination
Bare steel needs protection in most buildings. We establish the fire resistance period the building needs from Approved Document B, then specify intumescent coating, boarding or, where the calculations allow, leave sections unprotected on a fire-engineered basis. Corrosion protection is chosen to suit the environment, from a simple painted finish indoors to galvanising for external or damp conditions, so the frame lasts its design life.
A steel frame only works when it is coordinated with everything around it. We set out the grid with the architect, agree service zones and holes through beams with the M and E designers, and confirm the cladding and flooring systems the secondary steel has to support. Getting that coordination right before fabrication starts is what keeps the programme, since a change to a steel member after it is cut is slow and expensive.
What we check.
The points our calculations resolve for a project like this.
- Framing system chosen for span, programme and future flexibility
- Member design to BS EN 1993 for strength, deflection and buckling
- Braced versus moment stability strategy across the whole frame
- Buildable connection, base plate and holding-down bolt details
- Fire protection period and corrosion class for the environment
- Grid, service zones and cladding coordination before fabrication
Issued drawings, redacted.
From enquiry to sign-off.
Enquiry
Send drawings or describe the problem. We confirm the scope, the deliverables and a target timescale.
Information
We agree the survey, drawings or data we need and any site access required.
Engineering
Design, calculation or assessment to the relevant Eurocodes and UK National Annex.
Issue
A clear, defensible report or set of calculations, with assumptions and limitations stated.
Common questions
Why choose a steel frame over concrete or timber?
Steel gives long clear spans, a fast erection programme and easy future alteration, which suits most commercial and industrial buildings. We compare the options for your project and recommend the frame that carries the loads at the lowest overall cost and programme.
Do you produce the connection design as well?
Yes. We design the connections, base plates and bracing, not just the member sizes, and we present them so the steelwork contractor can fabricate directly. Clear connection design is what keeps queries and delays off the fabrication drawings.
How is the steel protected against fire?
We work out the fire resistance the building needs, then specify intumescent coating, boarding, or an unprotected fire-engineered solution where the calculations support it. The choice depends on the required period and how the steel is exposed.
Can you work from an architect's concept?
Yes. We take the architect's grid and concept, set out the frame, coordinate services and cladding, and deliver calculations and drawings for fabrication. We work with design teams across the UK.
Related in commercial, industrial & agricultural structural engineering.
Tell us what you are building.
Send the drawings or describe the project. We confirm scope, deliverables and a realistic timescale.
Start a project