Delivering solutions through prefabrication

Jeff House, Marketing & Applications Manager for Baxi Commercial considers the role of prefabricated solutions in the Government Construction Strategy.

The use of offsite prefabrication and modular design in building services schemes is nothing new; this approach lends itself especially well to plant rooms and can offer significant project benefits. With fully formed and time proven solutions available to the market both in standardised and bespoke packages, it is time to consider the integration of offsite manufacture wherever practicable.

p17baxi1 Back in 1994 the Latham Report identified industry inefficiencies, claiming that the process of building delivery was ‘fragmented’, with significant potential for modernisation. Following on from these themes, 1998 saw the publication of the Egan Report which detailed opportunities to improve the efficiency and quality of the UK construction industry, making it more responsive to client needs. A key recommendation by Egan was the use of prefabrication, together with standardisation, claiming that advantages include ‘speed of construction, lower cost, reduced need for skilled labour and achievement of zero defects’.

Despite some progress in addressing the issues raised by both Latham and Egan, there is still much headroom for streamlining project delivery and improving collaboration, hence the publication of the Government Construction Strategy in 2011. This document is somewhat of a departure from the usual approach of regulation and recommendation, indeed, the strategy is effectively the Government acting as a client, setting requirements from supply chain parties who wish to engage in public funded construction projects.

The Government Construction Strategy claims that public funded construction projects account for circa £44 billion annual spend, incorporating infrastructure as well as the built environment. Furthermore, the strategy document claims that central Government departments do not obtain full value from this activity and sets out a series of measures designed to reduce overall construction spend by 20% by the end of this parliament.

Not least of these measures is the requirement that: “Supply chains are engaged on a serial order basis of sufficient scale and duration to incentivise research and innovation around a standardised (or mass customised) product”, clearly opening the door for offsite manufacturing. Amongst other requirements is the delivery of project data using 3D collaborative Building Information Modelling (BIM) work processes, which again offers opportunity for the integration of prefabrication at design stage with the pre-requisite efficiencies this brings. The way we procure, design and construct assets simply has to modernise and the Government Construction Strategy delivers a clear message in this regard; ‘come with us or be left behind’.

Prefabrication benefits

Government rhetoric aside, a persuasive case can be made for the use of prefabrication in many situations, with a considerable array of features and benefits offering added value to projects in both the new build and retrofit arenas. Lower overall cost is one of the major advantages of prefabrication which is readily recognised in our industry where perhaps price is often the key concern above all else. Importantly, an offsite approach can not only achieve savings over a conventional installation but can also improve the quality of the delivered asset. When taking into account site labour, material wastage, commissioning, programme savings and quality control, overall project cost savings of up to 30% versus the traditional method of delivering a plant room installation have been reported.

p17baxi2Procurement, design and maintenance are also simplified. Particularly, in the case of a prefabricated plant room designed by a boiler manufacturer where all components have been originated, selected and supplied from a single source thereby simplifying procurement and delivery of operating and maintenance information. This also allows the plant room design to offer the most effective footprint, whilst taking full account of the ease of on-going service and maintenance of plant and ancillaries. Where effectively scheduled into a project delivery programme, the manufacture of the plant room off-site allows other elements of the scheme to continue unfettered by access issues and the like. Safety on site is improved as the finished plant room is delivered when needed rather than being assembled in situ.

Clearly the reduction in hot work and construction helps, whilst, additionally, security concerns are mitigated as high value plant and pipework are not stored on site. Commissioning, testing and quality assurance processes are carried out by the plant room manufacturer, further streamlining the processes and responsibilities of site management. When appraised in terms of whole life cost, prefabricated plant rooms perform especially well owing to simplified maintenance and modular design, amongst other factors, that has prompted significant interest from major end users.

Solutions of choice

Prefabricated plant rooms have been the solution of choice in the utility and industrial sectors for many years, demonstrating a proven track record of reliability and durability in critical applications, given the inherent ‘safe by design’ approach and, where required by client specification, service redundancy of boiler modules which allows maintenance without interruption of performance. Off-site prefabrication allows for optimum design and integration of heating plant, be it gas fired or from a low carbon source.  Biomass applications in particular can be vastly simplified where the boiler, fuel store, fuel delivery system and buffer vessel are considered as a consolidated package. It is often the case that entire packaged plant rooms are sited external to a building, with an appropriately designed enclosure included, which is eminently suitable where sufficient roof space or floor space is available on site.

Building upon experience in delivery of such items, there are elements of prefabrication becoming commonplace for internal boiler room installations. The use of modular header kits and modular boiler assemblies brings much of the benefit identified above to bear at a smaller scale. When replacing existing boilers, particularly in the case of the healthcare and hospitality sector, modular assembly can drastically reduce installation time, thereby mitigating downtime of the heating plant. When the Energy Related Products Directive (ErP) is implemented in 2015 prefabrication will offer a smart solution to boiler replacement. Non-condensing boilers below 400kW output will be removed from sale, thereby preventing like for like replacement of older boiler plant. In many instances such plant will be in a basement plant room or other location with restricted access, which may preclude the application of larger floor standing condensing boilers. In such instances, modular wall hung boilers will offer a tidy solution.

Off-site prefabrication and packaged plant rooms offer a time tested and robust option when considering boiler plant in all situations. With a clear Government preference for this delivery method and a wider acknowledgement of the associated benefits within client organisations, it is safe to say that the time has finally come for off-site manufacture to go mainstream in the H&V market. Leading manufacturers have the experience, expertise and technical resource to offer solutions from modular header kits through to fully bespoke complete plant rooms of any output or configuration desired.

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