Continuing Professional Development Offsite M&E manufacture
building. Manufactured products can be incorporated equally into new build and refurbishment projects and enable main contractors to signifi cantly reduce and re-sequence programme periods. The factory conditions enable high
levels of safety, productivity and quality to be reached and enhanced sustainability benefi ts, effective cost control and programme certainty to be achieved.
In addition, utilising the just-in-time manufacturing philosophy, each modular component is designed and built only when needed. Project managers can generally work on the basis that offsite products could save as much as 15% compared with the traditional installation and at worst give a cost neutral outcome. And this does not take account of the hidden cost benefi ts. The offsite manufacturing process can help site management by reducing the number of resources on site, leading to reduced logistics and welfare arrangements. Meanwhile, site scrap, packaging and waste materials are minimised as these are all accommodated within the lean processes offsite.
Broad-ranging role The role of offsite manufacture on any project is broad ranging and can be extended from the supply of common M&E products such as multi-service corridor modules with pipework, ductwork and electrical containment to much larger products where the building structure and fabric is incorporated, for example in multi-sectional plant rooms. In reality, the only limitation to the
size of product which can be designed and manufactured offsite is the transportation, where vehicle size and highway regulations dictate and commonly restrict load sizes to 14m x 4m x 4m. Though the amount of services that come in modular form varies from project to project, as a rule of thumb, 60-75% of M&E “fi rst fi x” installation works are offsite (that is, the infrastructure for services like cables and pipes for water and electrical services). After that, 70-100% of M&E work in plant rooms is now offsite. There are almost no restrictions on the
use of offsite manufacture — the main considerations that can impact a decision
to use it include site logistics and access. Early engagement during the design and planning phases will identify these points and enable restrictions to be incorporated. Products are split into four key
categories: multi-service horizontal (corridor) modules; vertical (structural) risers; sectional plant rooms/plant skids; and modular wiring systems. Within each of the key categories further sub- components are manufactured. The product manufacture is dependent on good quality 3D CAD drawings fully coordinated with the building structure — so the use of modular construction processes works best when an integrated approach to design of the structure and services is adopted. Often, the structure is designed with services being something of an afterthought. Using these processes the product assembly becomes straightforward with clashes eliminated and technical issues and access all visible at an early stage. A major benefi t to clients is the ability to produce prototypes of products which can be inspected and trialled prior to construction works starting on site. Products manufactured and assembled
in offsite conditions are subject to strict quality assurance processes which result in high-quality standards with full traceability of testing and inspection, something not always achievable with conventional site installation.
A modular riser is prepared to be lifted into position at HMP Oakwood
As mentioned above, the delivery of the
M&E products must be considered at the earliest stage of the design, planning and programming of the project to achieve the maximum benefi t for all parties. Suffi cient upfront time needs to be allowed to carry out the design and engineering activities and then to consider these within the overall build strategy for the project. If considered early enough, signifi cant additional benefi ts can be gained through incorporation of other construction activities within the offsite strategy, for example ceiling details and supports, and partition wall construction including fi re stopping. The time spent early in the project will drive programme benefi ts and can realise 30-40% savings in the time required for fi rst fi x activities.
Building relationships The early involvement must then be used to build relationships and collaborate with other members of the design team to develop a fully coordinated and complete design. This is essential to ensure the manufacturing process is used to provide its maximum benefi t in terms of buildability, repeatability and quality. Although each modular component is designed and then manufactured only when needed, planning of the handling and movement on site must be considered in the build programme to prevent the need for costly storage.
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