BIM revolution
BIM defines a process for creating computer models of buildings populated with detailed information about the technical specification of the internal elements. This can include everything from the dimensions of windows, to the thermal performance of pipe insulation. We have created a number of product specific BIM objects that can be freely downloaded from the BIMstore.
In Level 2 BIM, the various contractor teams are responsible for creating models for their individual elements of the construction using platforms such as REVIT. To allow improved collaboration, these models are integrated into a master model at set-points within the process.
In practice, this integration process has proven particularly beneficial for building services as the software can automatically flag up errors, such as clashes between the various elements. This allows issues to be resolved before work starts on-site, providing greater design certainty and supporting the increased adoption of offsite methods.
Make it modular
By moving the fabrication of building services away from construction sites and into dedicated manufacturing facilities where the construction process is carried out in more controlled, cleaner and safer conditions, overall project efficiency can be significantly improved. NG Bailey have reported that cost savings of up to 35% and time saving programmes of 90% have already been reached through the use of offsite methods whilst further studies have suggested a total reduction in site time of between 60 and 80% can be delivered.
There are a variety of reasons for these dramatic improvements. Construction sites are usually heavily congested and even minor delays to one trade can have a notable impact on sequencing. A shortage of skilled labour in the UK also means that whilst workers are tied up waiting for their chance to complete work on one building, other projects are falling behind.
These issues are particularly acute for building service installers as a number of systems have to be fitted within the cramped service space. For example, research from Bucknall and Austin highlighted that the fit-out time for pipework and its insulation is extensive and critical.
In contrast, offsite production facilities provide a safer and more easily controllable environment. Modular service units can be fabricated in preassembled standard configurations to a clear and reliable schedule, unimpeded by the work of other trades. Skilled labour requirements are greatly reduced as staff no longer have to move from site to site and onsite assemblies have been simplified. Access to all sides of each section is also enhanced allowing better quality control, particularly on large and complex service modules.
Once completed, the sections can be held in storage until the site is ready to receive them, helping to avoid programme clashes. Larger modules can be lifted into place with heavy machinery, often eliminating the need for scaffolding. In addition, site waste is also greatly reduced as most of the detailed adjustment and fabrication work has already been completed.
In practice
One project which has recently benefited from the use of offsite approaches is Airedale International Air Conditioning’s Headquarters. Following a serious fire, the building needed to be quickly reconstructed. BAM Construction used BIM at the design stage and made the decision to deliver the industrial development as a turnkey project to help save time and resources.
All pipe insulation used on the project was required to have FM Approval. This led to the specification of Kingspan Kooltherm Pipe Insulation. In addition to its excellent fire performance, the insulation also supported the extreme temperature range required for the research and development test chamber — ranging from -20 to +50 Degree Celsius.
Nick Howdle, project manager from BAM Construction discussed the project:
“Using BIM has been an invaluable resource for ensuring that we could accurately estimate the costings and timings, including effectively overlapping M&E installations without incident. We would have struggled to achieve the programme without offsite methods. BIM helped with clash detection, and we had zero snags with the pipework. On a £1.3 million package that is highly unusual, if not unheard of.”
