Through our long standing relationship with the BCSA, Building Systems UK has been part of the development of the new BCSA technical specification for ‘boundary’ elevations.
This guide came effective on the 1st July of this year, below is a summary of what this document covers.
- Scope:
It covers primary frame, secondary steelwork (side rails & purlins), and external wall cladding.
- Objective:
Ensure a robust load path in fire conditions so fire-resistant cladding remains supported.
- Engineered Concept:
Cladding is hung from protected structural support (i.e. ‘Capable member’) - No reliance on unprotected secondary steelwork.
The “Capable Member” is a protected structural support beam designed to carry vertical loads during a fire. It is typically positioned at the top of a cladding drop and may also be required at intermediate points for tall structures, at system transitions (such as between vertical and horizontal cladding), or where there are joints in the cladding, like liner overlaps.
Download the Building Systems UK technical guidance note >
Download the BCSA technical specification for boundary elevations >
For further information or technical advice email technical.envelopeproducts@tatasteeleurope.com
or call +44 (0)1244 892199.

This design change requires careful coordination by the Principal Designer during the development of the steelwork package, involving input from both primary and secondary steel suppliers, as well as the cladding manufacturer, in close collaboration with the cladding contractor.
This will inevitably add cost and increase the carbon footprint of steel frame designs located within boundary distances. However, Building Systems UK has developed robust engineering methodologies for the integration of capable members, combined with efficient cladding connection designs, to minimise this impact. These solutions have been achieved through close collaboration with secondary steelwork and fastener suppliers, along with advanced high-temperature stress testing of connections.
Please initiate early contact with our technical team to establish communication and align on design requirements, ensuring a smooth and efficient design process
Download the Building Systems UK technical guidance note >
Download the BCSA technical specification for boundary elevations >
For further information or technical advice email technical.envelopeproducts@tatasteeleurope.com
or call +44 (0)1244 892199.
EN-Construction-Contact-BSUK envelope
Building Systems UK technical team - Building Envelope
