Gordon Moffat, technical manager at CMS, Scotland’s largest door, window and curtain walling manufacturer and installer, discusses the advantages to architects of ‘BIM ready’ contractors and how BIM can optimise building envelope performance.
As more and more product and system manufacturers invest in BIM to ensure architects have ready to use BIM elements at their disposal, it is crucial that the success of a building project is not compromised due to contractors or sub-contractors lacking the same skills and technology.
Since the emergence of BIM, much of the talk around this shift in the way we design and deliver buildings has been around encouraging architects to adopt BIM and learning how systems manufacturers are making their components available for projects. Somewhat overlooked has been the importance of contractors and sub-contractors being on the ‘same page’ – after all, they are equally important links in the supply chain.
As contractors, we need to ensure that we have the right level of competence and the right software to work on BIM projects effectively. Moving to this point at this stage in the evolution of BIM, however, is not something that a contractor will enter into lightly – it has to be a strategic decision which demands significant investment in people, training and infrastructure. Fortunately, forward thinking contractors are increasingly making the step up to being ‘BIM-ready’.
By being BIM-ready, a contractor is the link between the design team and product manufacturers. What it means to the architect is an additional layer of support. For example, knowing that your facade contractor is able to take your BIM model and detail design elements as much as is necessary will help avoid delays further down the line. It provides a safety net underneath the architectural concept, the standard product BIM objects which look most suitable for the project and the practicalities of how the system is most efficiently manufactured and installed.
Product manufacturers also value BIM-ready contractors as they recognise how an experienced manufacturer and installer will sometimes need to apply a system in new ways, often to help an architect to overcome a particular challenge. The contractor’s knowledge of BIM in these situations therefore helps reduce delays on technical matters which may otherwise have to be dealt with by a hard-pressed and sometimes distant technical department.
As in the pre-BIM era, the contractor is best placed to understand how a given product or system will work in the application, taking a project from the theoretical to the reality. Early stage involvement by a contractor is almost always beneficial and this is another way in which BIM is revolutionising things – we can now collaborate with architects by having the 3D model accessible online and in a format that can be edited with ease.
Looking ahead to the immediate future, while there is still a lot of work for the industry to do, contractors are playing an increasingly important role in shaping the long-term success of BIM. Nowhere is this more evident than with our curtain walling projects.
Much of this is to do with the way design software integrates with estimating and production software. By potentially bringing together the major software systems routinely used by aluminium curtain walling fabricators and installers, we will make the design and delivery of buildings more automated and smoother with less scope for errors. Steps towards this integration have already been taken and it should be just a matter of time before the benefits are realised.
As a result, the widespread adoption of BIM is set to deliver multiple efficiency benefits, including in terms of building performance. BIM encourages truly integrated design approach, all collaborators in the design and build process can feed their expertise into the 3D model at an early stage. The envelope design can therefore be refined for improved performance – as required – taking the predictability that comes with the BIM object’s data, including embodied carbon figures.
This is a much more accurate way to create a building envelope with the most appropriate levels of thermal and acoustic insulation, as well as aiding solar control and natural daylighting objectives to manage overall energy efficiency of the building in-use. This BIM model data is also fundamental to performance monitoring during the building’s whole life cycle, ensuring easier comparison between predicted and actual.
BIM software typically incorporates an integrated thermal performance module too. At the product selection phase, this allows architects to explore different options for their design to ask environmentally based “what if” questions. So crucial aspects of the design can be modelled and evaluated, such as building orientation and building massing, which will have a significant impact on the design of the building envelope.
There are also direct advantages with the ability to cut through the BIM model’s 3D sections throughout the building design. This can highlight design issues, such as thermal bridging, which can be resolved prior to construction and avoid costly delays or redesign further down the line.