Standardised steel – a new construction platform?
Structural steel already adds value through its offsite manufacturing processes – but could proposals for a standardised ‘platforms’ approach to construction bring further productivity gains? By Sarah McCann-Bartlett.
The government has previously stated its ambitions for construction and infrastructure projects to utilise greater levels of offsite manufacturing to drive increased productivity and reduce costs. More recently, government has indicated that it also wants to take a more standardised approach to design, including componentisation. This is sometimes referred to as a “platforms approach”.
With the majority of the added value for structural steel already occurring offsite – in some cases up to 90% – the structural steelwork sector is well placed to be an early adopter of these new approaches.
The view of steelwork contractors is that a shift towards a platforms-type approach will allow reduced costs and increased efficiency along a transformed supply chain. Benefits are likely to include changes to the commercial and procurement model, improved collaboration and a shorter supply chain.
Key to the success of this will be the ability to lock down the complete design, with a full view of the supply chain.
“The current delivery model does not allow the design to be fixed and drives late changes driven by individual subcontractors as they are engaged.”
The current delivery model does not allow the design to be fixed and drives late changes driven by individual subcontractors as they are engaged. This lack of design certainty is the biggest issue facing steelwork contractors today and one of the largest drivers of cost.
The British Constructional Steelwork Association (BCSA) believes late and incomplete design, design errors and ongoing design changes could currently add up to 15% to 20% in cost to a project. Steelwork contractors are frequently instructed to commence fabrication before the design is finalised, and certainly before many of the other subcontractors are engaged. This leads to rework, often on site, and costs increase.
For a platforms approach to be successful, the construction delivery model will have to become collaborative, incorporate early engagement, and demonstrate a high level of coordination and integration. A specific benefit is that it will make the design process easier and therefore the design could be finalised faster. Fixity of design and early engagement of subcontractors would be a significant positive change.
While the structural steelwork sector already commonly uses a narrow range of section sizes and three standard connection designs, as well as generally using one standard bolt size, the overall building or structure design is sometimes so bespoke that the standard components and designs are unable to be utilised as often as they could be.
Formalisation of standard details, including standard architectural details, so that standardised solutions and components can be used would reduce the number of steel components and sub-designs used in an “average” structure.
A balance does need to be struck between over and under application. If a platforms approach standardises more than is practical, it may be that the building design becomes less efficient than other design solutions.
Alternative to offsite systems
In its early stages, a platforms approach is most likely to be an alternative to modular and panelised offsite build systems, for example, in student accommodation, low rise hotels and low rise residential type structures. This is due to their regular grid, repetitive design and limited number of storeys.
Steelwork contractors already feed the BIM model into the manufacturing process, so it will be important that software houses incorporate standardised components into their packages.
While a platforms approach itself will not necessarily be the optimum solution for all projects, the principles of fixed or standardised design and interoperability can provide a solution for many buildings and will have wider benefits in effecting positive change.
Sarah McCann-Bartlett is director general at the British Constructional Steelwork Association