Home Features Off site fabrication –  are we embracing  the benefits?

The push to de-skill the construction site and  reduce waste as far as possible has seen the  industry shift towards off-site fabrication. The  finishes and interiors sector is no different, but is  it going far enough? Paul Thompson reports.

It has been 20 years since Sir John Egan published his ‘Rethinking Construction’ report. Sanctioned by then Deputy Prime Minister John Prescott, the report looked at the fundamentals of the industry: how it designed, procured and delivered projects, and how contracts were drawn up, divided and paid.

It was one of the first official wide-ranging reports to promote the increased use of off-site and modern methods of construction to not only boost the quality of the industry’s offering but also manage the lack of skilled trades coming into the sector.

Since then, of course, warnings over skills shortages have become ten a penny and the introduction of off-site construction – if not as wholly embraced as Mr Egan first wished – at least no longer raises eyebrows.

For many, the experience of off-site construction or prefabrication will be based around the introduction of fully fitted out bathroom pods or kitchens in new build residential apartments, student halls of residence and hospitals. But the advantages of prefabrication and its use can help in most situations on most sites. The commercial fit-out sector may not be the most obvious of sectors to benefit from off-site preconstruction but its use can bring tangible improvement to a scheme.

“We have embraced the use of prefabrication in all its guises,” said Matt Hurrell, preconstruction director at ISG Plc, adding, “We look to bring in efficiencies whenever we can and that means we look at the potential use of prefabrication techniques on each project. We take each project on a case-by-case basis and work with our supply chain to assess where those efficiencies can be brought in.”

On some of ISG’s recent projects, this has seen the firm use its supply chain to work together and develop ideas ranging from a combined  lighting and chilled beam unit to bespoke modular pod meeting areas.

Mr Hurrell added: “There is a perception that for successful prefabrication you need repetition and that anything bespoke is difficult. That may be true but it doesn’t have to be repetition on-site. You could just as easily look at the supply chain. By bringing them together and giving them the opportunity to pool ideas, you can develop off-site solutions and, with them, greater efficiency.”

By their very nature, fit-out projects tend to be swift turnaround work. The opportunities to work on larger schemes with a longer lead-in can be few and far between. But that shouldn’t stop designers, contractors, specialist subcontractors and manufacturers from looking at any  opportunity for prefabrication that may be available, argued Mr Hurrell. At the very least, this means the supply chain can look at opportunities for how to bring materials or products to site, and how to prepare and install them efficiently.

Prefabrication offers the surety of construction conditions and the maximisation of skilled trades and can also dramatically cut back on the amount of waste produced throughout the supply chain – not just wasted material, but wasted time too.

Productivity boost

Earlier this year, materials supplier Etex Building Performance teamed up with research company BRE (Building Research Establishment) in a joint study of the efficiency of the drylining sector. It found that on-site  preparation work, such as measuring and cutting boards, accounted for a third of ‘non-value’ time. Material handling was responsible for almost 20 per cent of inefficient working.

“We wanted to really be able to look at and define efficiency,”  commented Nicola Chapman, marketing and business development director at Etex Building Performance. “As an industry, we need to understand the value of time. That is why we linked up with BRE for this study.”

That drive to boost efficiency on-site, claimed Ms Chapman, has seen it introduce products that can help cut installation time, such as its Weather Defence sheathing board among others.

Ms Chapman added: “There are many areas that we can look at. Now we have demonstrated that preparation and material handling account for so much inefficiency, we should look at the way we work and what we can do to rethink how we build.”

That may be easier said than done. With many projects still going through the design stages as they are being built, it can be difficult to introduce prefabricated elements without the need for on-site tweaking. Certainly, for some specialist partitioning and drylining subcontractors, the use of  preformed components such as bulkheads can prove just as time consuming.

“The problem is that projects are never perfect – there is always something that isn’t quite in line or doesn’t measure up,” explained Tom McLoughlin, CEO at MACS Plasterboard Systems, adding, “We find that although there are preformed systems available, it can take just as much time and skill to adapt them as standard working takes.”

It is a moot point but one which the increasing use of BIM throughout the supply chain, pushed by the main contractors, could help alleviate in the not-too-distant future. The availability, immediacy and accuracy of construction information that BIM models offer each member of the chain should mean that manufacturers, subcontractors and specialists can all work with a greater degree of confidence.

“A site today is still working in pretty much the same way as a site 20 years ago. Think of the advances that the manufacturing sector has taken over the same period,” said Ms Chapman.

“The industry needs to be looking at more prefabrication and more automation. BIM has the potential to make sure everyone in the supply chain – designers, architects and engineers included – works more efficiently,” she concluded.

Portview pre-manufactures ceiling raft at Wembley 

Club Wembley’s One Twenty, refurbished by Portview Fit-Out

Portview has completed a high-end refurbishment of One Twenty, the exclusive members’ club at Wembley, England Football’s national stadium, which opened last month and features a stunning bespoke ceiling design from KSS (see photograph above and right).

On appointment, Portview developed the fabrication details for the ceiling in close liaison with KSS. The criss-crossing blades were set out at full size onto 12 separate template sheets. The raft was then built on top of these template layouts to ensure all pieces fitted together correctly and lines were kept as straight as possible. Rafts for the two lounges were pre-manufactured off-site and installed on-site in seven days.

The lounges’ raft ceilings are five metres wide and 10.6 metres long, with various out-reaching fins that go beyond the outside edges of the framing. The blades are 200mm deep and made from Class O MDF veneered and sealed with FR Lacquer. Individual cells were then picked out in a blue colour lacquer chosen from the approved colour palette. A selection of cells are fitted with acoustic foam fabric-wrapped panels as part of the sound reduction scheme for the space, which includes a fabric screen above the balcony edge panelling.

During the first-phase works, Portview had to work around existing services and install a secondary uni-strut support grid. These works had to be agreed and set out 16 weeks before the final rafts were installed.

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