CC3001

TECHNOLOGYfocus
Off-site Fabrication
The off-site manufacture of building components is changing the way the construction industry
works, introducing significant cost-savings and other benefits
How is it possible to build a bridge in
Holland, ship it across the Channel,
and put it together in Dublin, and
yet do it for half the price that it would have
cost to erect it on site? That's the point that
BuildOffSite's Richard Ogden made at
Trimble's recent conference in Coventry.
Stretching the point further, he said that
car manufacturers do it as a matter of
course - with 2 million options available to
them, but with 80% conforming to common
platforms - most of them are identical with
mere badging differences between them.
In fact many companies own competing
brands (Rolls Royce owned by BMW, for
instance) and reap the benefits from
shared components.
At the most basic level there is little
difference between manufacturing and
construction industries, and most buildings,
even the business of updating period
houses, can be put together from
components manufactured off-site. In fact,
in London, he added, 85% of building
components are prefabricated, and even
more significantly, in the recent case study
in this magazine on the new entrance to
Leeds station, the site's location preempted
the storage and construction of the
building, and much emphasis lay in the
fabrication of components, and their
delivery to the site using the river.
Do not, Richard warned though, consider
that the process of increased off-site
fabrication is merely a reaction to local
requirements, but a shift towards a more
efficient way of construction - he considers
it to be a 'disruptive' technology, in the
same way that Uber, AirB&B and Tesla are
reinventing their particular markets. Five
years ago they were not even names in
telephone directories, but now they are
changing the way their industries operate.
In a similar way, Off-site fabrication
presages an entirely new approach to
construction that renders the traditional
construction site somewhat archaic and
dysfunctional.
To give just one instance, Richard had us
imagine a typical building site with several
workmen standing around, leaning on their
shovels - twenty men watching two men at
work - inefficiently engaged on a serial
construction process, and compared that
to a delivery of building components,
delivered JIT (Just In Time - a common
phrase in manufacturing) and ready for
instant erection by a dedicated team. A
more striking example is, perhaps,
provided by Chinese companies building
skyscrapers manufactured off-site in just a
couple of weeks.
IMPOSSIBLE WITHOUT BIM
This would have been impossible, though,
without BIM. Companies that have invested
in the BIM process are well placed to take
advantage of off-site fabrication, such as
Trimble, and KPMG, quoted by Richard as
a company taking the vision of Smart
Construction fully on board.
Trimble's route to Smart Construction was
outlined by Kevin Lea, Product Manager -
A&D Solutions at Trimble, in his later talk on
the technical efficiencies of BIM. With
reference to Trimble's own structural
engineering applications, Kevin outlined the
relationship between Tekla Structures and
Tekla Structural Designer, explaining where
each was most likely to be used, and how
they fitted into the architects and engineers
working processes - and, of course, how
they aided the off-site fabrication process.
Asking whether we get full value out of
BIM, Kevin expanded on the deliverables
that Consulting Engineers require from BIM
documentation / drawings from Tekla
Structures and code-compliant design from
Tekla Structural Designer and TEDDS.
Tekla Structural Designer being, of course,
Trimble's new software solution for the
structural design and analysis of buildings.
To place off-site fabrication in a current
context, Kevin described the relationship
between BIM and actual working
processes. Stating that although we
create drawings and Level 2 compliant
BIM models, which are shared with other
disciplines in the design team, sharing
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January/February 2017