Natalie Moore, environmental consultant at Arcadis, considers the applicability of building information modelling (BIM) to the environmental workstream.
I was recently asked how our environmental team is working with BIM. Its sudden domination in engineering has taken me by surprise, and this article explores how BIM could benefit EIA co-ordination.
As an environmental co-ordinator working on the junctions 3 to 12 on the M4 smart motorway scheme I have a wide range of responsibilities, from contributing to technical aspects of the environmental statement to representing the environmental team at public exhibitions, yet neither in my studies or my working role had I come across BIM as a tool which could be used from an EIA perspective.
Arcadis defines BIM as using computer programmes to collaboratively design and detail construction projects through a 3D model from its’ conception through to its’ demolition.
A search of past articles on the IEMA website produced no references to BIM - is this because it is a new concept, or just one which has limited use within the environmental setting?
Misconceptions surrounding BIM
Common misconceptions surrounding BIM include ‘BIM is only suitable for buildings’ – this is not the case and many would say this is a mistake in the process name. BIM incorporates all types of construction from bridges, railways and roads to waste water treatment works, oil rigs and earthworks. Another misconception is that ‘BIM is all to do with 3D models’. But the 3D model side of BIM is only a small part of it. The most important part of BIM is the ‘i’ - the information contained within the model.
Why use BIM?
BIM provides the project team with a number of advantages. As an integrated model across all workstreams, with no limit on the number of inputs, it allows the design team to identify and resolve conflicts within one medium, theoretically reducing the number of unseen additional costs occurring during construction. Designs from all workstreams can exchange information which is then visible through computer-aided design (CAD) operations, streamlining the process and facilitating collaboration. BIM reduces the challenges of communication when several different workstreams interact, making it seemingly very applicable to the multi-disciplinary nature of environmental work.
The integration of BIM into the project design process is increasing in popularity; the M4 smart motorway scheme is one such example. To meet the detailed design requirements, the design team must produce a fully integrated 3D BIM model of all 51km of the scheme. All disciplines including highways, drainage, structures and technology should be involved, with real-time access for all the project team.
This model-based design approach should prove a helpful method for dealing with the complexity of the project.
Environmental involvement
While I understand the basic principles of BIM in terms of engineering design, and the benefit of having one central modelling system for all scheme information, it is important to understand how the environmental workstream can contribute.
GIS can be integrated into the 3D model to show the surrounding environment. For the M4 scheme, the environmental BIM input is through the integration of the environmental masterplan and vegetation clearance drawings into the 3D model, to simulate areas of vegetation clearance surrounding the gantries, overbridges and other structures. Similarly protected assets, including heritage listed buildings and scheduled monuments, can be modelled alongside ecology target notes and other planning features, such as designated sites and public rights of way. The presence of environmental barriers can also be included, both those pre-existing and those proposed as a result of the EIA process, alongside more environmental information such as the locations of proposed otter fencing and mammal ledges.
Pros and cons
BIM is purely a modelling tool, it cannot assess environmental constraints or offer solutions where conflicts arise. However, it provides a holistic viewpoint of a project, allowing layers to be turned on and off, and existing and future information to be manipulated and combined to create the big picture in 3D, which has clear advantages compared to geographical information systems and CAD.
Conclusions
This article has highlighted the potential of BIM within large infrastructure schemes, but incorporating key features as a result of the EIA process is still an emerging concept, not widely known or used. While this article only scratches the surface, it hopefully raises interest in applying BIM in EIA. As for the M4, only time will tell whether BIM proves as beneficial for this scheme as it has for many others already.
