# Steel Portal Frame EC3

> Specialized Portal Frame Analysis and Design for Single-Storey Industrial Structures

Canonical: https://www.ramcadds.com/products/steel-portal-frame-ec3
Source: RAM CADDSYS product catalog — https://www.ramcadds.com/products
Last verified: 2026-07-18
Categories: building-components

Steel Portal Frame EC3 is a specialized portal frame design and analysis software per Eurocode 3, optimized for single-storey industrial structures. It handles the complete design workflow for steel portal frames including analysis, member design, haunch design, and connection verification to EN 1993 standards.

Steel Portal Frame EC3 is a Eurocode 3 design program from RUNET Norway AS, distributed in India by RAM CADDSYS, purpose-built for single-storey, single-bay steel portal frame buildings. One workflow carries frame analysis, rafter/column/haunch member design, bolted eave/apex/base connections, base anchoring and reinforced-concrete foundation design, with gravity, snow, wind and seismic combinations generated automatically. It also designs purlins and bracing for warehouses and factories.

Steel Portal Frame EC3 by Runet Software is a purpose-built design tool for single-storey, single-bay steel portal frame structures per Eurocode 3. It performs linear-elastic finite-element analysis of the frame and covers rafter, column and haunch member design, bolted eave, apex and base connection design, base anchoring and reinforced-concrete foundation design in one workflow. Optimized for the most common industrial building typology, it delivers a faster, more focused design cycle than general-purpose structural software, generating frame geometry from minimal input and producing fabrication-ready CAD drawings and calculation reports.

## Key points

- Steel Portal Frame EC3, developed by RUNET Norway AS, is purpose-built for single-storey, single-bay steel portal frames rather than a general-purpose frame package adapted to the job.
- It carries the design through one workflow to the Eurocodes: frame analysis, rafter/column/haunch member design, bolted eave/apex/base connections, base anchoring, and reinforced-concrete foundation design.
- Haunch stiffening at the eaves and apex is built into the frame analysis itself, by increasing the stiffness of the rafter elements, so the effect carries through to member verification.
- Gravity, snow (EN 1991-1-3), wind (EN 1991-1-4) and seismic (EN 1998-1) loads and their combinations are generated automatically, with National Annex selection for country-specific parameters.
- It also designs roof purlins and lateral bracing, and exports fabrication-ready CAD drawings (DXF/PDF/WMF) alongside PDF/DOC calculation reports.
- RAM CADDSYS supplies Steel Portal Frame EC3 in India with licensing, training and technical support.
- Purpose-built for the single-storey, single-bay steel portal frame — the most common industrial-building typology — rather than a general-purpose frame package adapted to it
- Covers the whole job in one tool: frame analysis, rafter/column/haunch member design, bolted moment connections, base anchoring, and concrete foundation — to the Eurocodes
- Generates frame geometry from minimum input, with data entry and analysis/design on essentially one screen for a fast design cycle
- Haunch stiffening at eaves and apex is modelled by modifying the rafter element stiffness, so the haunch effect is captured in both analysis and member verification
- National Annex selection lets you apply country-specific Eurocode parameters
- Produces fabrication-ready CAD drawings of the frame and connection details, with DXF, PDF and WMF export plus PDF/DOC calculation reports
- Includes purlin design (continuous or simply supported, restrained or unrestrained) and vertical/horizontal bracing design
- Backed in India by RAM CADDSYS with licensing, training and local technical support

## Why engineers pick it

- **Purpose-Built for Portal Frames** — Dedicated to the single-storey, single-bay steel portal frame — the most common industrial-building typology.
- **Full Eurocode Compliance** — Member design, stability checks, and bolted connection verification per EN 1993-1-1 and EN 1993-1-8, with National Annex selection for country-specific design parameters.
- **Whole Job in One Tool** — Frame analysis, rafter/column/haunch member design, bolted moment connections, base anchoring, and reinforced-concrete foundation — all to the Eurocodes in a single workflow.
- **Rapid Design Cycle** — Frame geometry is generated from minimal input, with data entry and analysis/design on essentially one screen.

## Capabilities

- **Portal Frame Analysis (Linear-Elastic FE)** — Linear-elastic finite-element analysis of the single-bay portal frame, with second-order effects accounted for through equivalent imperfection loads and amplification factors per EN 1993-1-1.
- **Rafter, Column & Haunch Member Design** — ULS cross-section resistance and member stability verification (flexural buckling and lateral-torsional buckling) for rafters, columns and haunched segments to EN 1993-1-1.
- **Bolted Moment Connection Design** — Design of bolted eave, apex and column-base connections to EN 1993-1-8, including end-plate and bolt-group detailing and base-plate anchoring against uplift.
- **Automatic Loads & Combinations** — Generates gravity, imposed, snow (EN 1991-1-3), wind (EN 1991-1-4) and seismic loads, and builds all ULS/SLS combinations to EN 1990. Seismic action is handled by the lateral-force method and modal response-spectrum analysis to EN 1998-1.
- **Purlins & Bracing** — Design of roof purlins (continuous or simply supported, laterally restrained or not, with sheeting restraint considered) and of vertical and horizontal lateral-bracing systems.
- **Foundation Design & Drawings/Reports** — Concrete pad-footing design to EN 1992-1-1 with geotechnical checks to EN 1997-1, plus CAD drawings (DXF/PDF/WMF) and editable PDF/DOC calculation reports.
- **Portal Frame Analysis** — Linear-elastic finite-element analysis of the single-bay portal frame, with second-order effects captured through equivalent imperfection loads and amplification factors per EN 1993-1-1.
- **Rafter and Column Design** — Member design for rafters and columns per EN 1993-1-1 including in-plane and out-of-plane stability checks, lateral-torsional buckling, and combined loading verification.
- **Haunch Design** — Eaves and apex haunches modelled by increasing rafter-element stiffness, then verified for cross-section resistance and stability per EN 1993-1-1 in the haunched zone.
- **Connection Design** — Eaves, apex, and base connections designed per EN 1993-1-8 with end plate details, bolt layouts, and base-plate anchoring against uplift.
- **Foundation Design** — Reinforced-concrete pad-footing design to EN 1992-1-1 with geotechnical checks to EN 1997-1 for the column bases of the portal frame.
- **Wind Load Generation** — Automatic wind load calculation per EN 1991-1-4 for single-storey buildings including pressure coefficients, internal pressure, and asymmetric wind load cases.

## Applications

- **Single-storey industrial sheds & warehouses** — Design of the steel portal frames that form the primary structure of warehouses, factories and storage buildings.
- **Agricultural & logistics buildings** — Rapid design of clear-span sheds, barns and distribution centres where the single-bay portal frame is the standard structural form.
- **Commercial & retail clear-span structures** — Showrooms, retail units and similar buildings needing a column-free interior delivered by a haunched portal frame designed to Eurocode 3.
- **Connection & foundation detailing for fabricators** — Producing the bolted eave/apex/base connection details, base anchoring and concrete footing design, with DXF/PDF drawings ready for the fabrication shop.
- **Eurocode compliance in seismic regions** — Portal-frame buildings in seismic zones where EN 1998-1 lateral-force or response-spectrum checks and the appropriate National Annex parameters must be demonstrated.

## In depth

### Why does a single-storey steel shed need a dedicated portal-frame program?

Because the single-bay portal frame is the industry's most common industrial-building form, and taking it from analysis through to a fabrication-ready connection and foundation design is faster in a program built around that one job than in a general-purpose frame package adapted to it.

A portal-frame warehouse or factory building is really one connected design problem — the frame has to be analysed, its rafters, columns and haunches verified, its eave, apex and base connections detailed, and its footings sized, all to a consistent Eurocode basis. Steel Portal Frame EC3 keeps that as a single workflow: frame geometry is generated from minimal input, and the same model carries through EN 1993-1-1 member design, EN 1993-1-8 bolted connection design, base anchoring against uplift, and EN 1992-1-1 reinforced-concrete foundation design with EN 1997-1 geotechnical checks, with the applicable National Annex selected once for the whole job.

Two details that matter for portal frames specifically are handled inside the analysis rather than as an afterthought. Haunch stiffening at the eaves and apex is modelled by increasing the stiffness of the rafter elements, so the haunch effect is captured in both the frame analysis and the member verification, not bolted on as a separate hand check. Gravity, snow (EN 1991-1-3), wind (EN 1991-1-4) and seismic (EN 1998-1, by lateral-force method or modal response-spectrum analysis) loads and their EN 1990 combinations are generated automatically, so the engineer works with the load cases rather than assembling them by hand.

### How does a design pass through Steel Portal Frame EC3, from geometry to drawings?

Frame geometry, loading and design settings are entered on essentially one screen, the program runs a linear-elastic finite-element analysis with second-order effects included, then verifies members and connections and hands off fabrication-ready drawings and reports.

The engineer defines the frame geometry, sections, loads and the governing National Annex, with data entry and the analysis/design results kept on essentially one screen rather than spread across separate modules. Steel Portal Frame EC3 then runs a linear-elastic finite-element analysis of the single-bay frame, with second-order effects accounted for through equivalent imperfection loads and amplification factors per EN 1993-1-1, before checking cross-section resistance and stability — flexural and lateral-torsional buckling — for the rafters, columns and haunched segments, and sizing the bolted eave, apex and base connections to EN 1993-1-8.

The same run also covers what completes the building envelope: roof purlins, continuous or simply supported and restrained or unrestrained, and the vertical and horizontal bracing system, plus the reinforced-concrete pad footings and their base anchoring against uplift. Output is fabrication-ready: CAD drawings of the frame and connection details export to DXF, PDF or WMF, and the calculation report is delivered as PDF and an editable DOC file on A4, A3 or A2 paper sizes.

## Design codes

- **EN (Eurocode — Steel)** — EN 1993-1-1:2005 / EN 1993-1-8:2005 / EN 1993-1-3:2005 / EN 1993-1-5:2006
- **EN (Eurocode — Actions & Basis)** — EN 1990:2002 / EN 1991-1-1:2002 / EN 1991-1-3:2003 / EN 1991-1-4:2005
- **EN (Eurocode — Concrete, Geotechnical, Seismic)** — EN 1992-1-1:2004 / EN 1997-1:2004 / EN 1998-1:2004 / CEN/TS 1992-4

## Questions

### What is Steel Portal Frame EC3?

It is a specialized RUNET Software tool for designing single-storey, single-bay steel portal frame buildings to the Eurocodes. It covers frame analysis, rafter/column/haunch member design, bolted eave/apex/base connections, base anchoring and concrete foundation design in one workflow.

### Who develops Steel Portal Frame EC3?

It is developed by RUNET Software (RUNET Norway as), a Norwegian developer of Eurocode-based structural engineering software with installations worldwide. In India it is distributed by RAM CADDSYS.

### Which design codes does it use?

It works fully to the Eurocodes: steel members to EN 1993-1-1, bolted joints to EN 1993-1-8, cold-formed purlins to EN 1993-1-3, loads to EN 1991 (snow 1-3, wind 1-4), combinations to EN 1990, concrete foundations to EN 1992-1-1, geotechnics to EN 1997-1 and seismic design to EN 1998-1.

### Does it design portal frame connections?

Yes. It designs bolted eave, apex and column-base moment connections to EN 1993-1-8, including end-plate and bolt detailing and base-plate anchoring against uplift.

### How does it handle the haunches?

The eave and apex haunches are modelled by increasing the stiffness of the rafter elements, so the haunch effect is captured in the analysis, and the haunched segments are then verified for cross-section resistance and stability to EN 1993-1-1.

### What type of analysis does it perform — elastic or plastic?

It performs linear-elastic finite-element analysis. Second-order effects are accounted for through equivalent imperfection loads and amplification factors per EN 1993-1-1, rather than a full elastic-plastic (collapse) analysis.

### Can it handle seismic loads?

Yes. It generates seismic loads and analyses the frame using the lateral-force method and modal response-spectrum analysis to EN 1998-1, with all relevant load combinations.

### Does it also design purlins, bracing and foundations?

Yes. It designs roof purlins (continuous or simply supported, restrained or not), vertical and horizontal bracing systems, and the reinforced-concrete pad foundations with geotechnical checks to EN 1997-1.

### Does it support National Annexes?

Yes. You select the National Annex within the program so that country-specific Eurocode parameters are applied to the design.

### What outputs and drawings does it produce?

It produces CAD drawings of the frame and connection details with DXF, PDF and WMF export, plus calculation reports as PDF and editable DOC files, on A4/A3/A2 paper sizes.

### Is it limited to single-bay, single-storey frames?

Yes. It is purpose-built for single-storey, single-bay portal frames — the most common industrial-building form. For multi-bay or multi-storey steel frames a general-purpose frame analysis/design package would be used instead.

### Is Steel Portal Frame EC3 available in India through RAM CADDSYS?

Yes. RAM CADDSYS distributes RUNET Software products in India, providing licensing, installation, training and technical support for structural engineering firms.

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