Since the MEP (M&E) industry worldwide is constantly on the turn to parametric three dimensional model-based building services style and coordination processes, the question of who what between contractors as well as consultants has re-emerged. Among the challenges in the contemporary building services industry issues the effective control associated with BIM models between MEP Experts and MEP Contractors.
BIM has benefits including: greater collaboration in between stakeholders, improved design overall performance, less constructability issues on-site as well as cost efficiency. However, implementing BIM requires effectively managing scope definition and delivery along with the information flow between the actual MEP (M&E) consultant, the actual MEP (M&E) contractor, a number of sub-contractors and shop fabricators. Nevertheless, BIM can create range overlap (and therefore costs and delays for that project) between MEP (M&E) experts, contractors and other downstream individuals.
In the traditional program, where 2D design information is received, the MEP contractor would result in services coordination and conflict detection. He/she would overlay the actual 2D drawings of each one of the services (HVAC, electrical, and plumbing) and execute a detailed coordination exercise – usually by utilizing 3D tools or by utilizing BIM tools. The end result will be a model that is spatially coordinated that may then be used with regard to installation drawing creation as well as subsequent fitting/installation.
The traditional approach (2D drawing deliverables) didn’t require design consultants to consider constructability and spatial coordination. Nevertheless, the BIM process requires MEP (M&E) BIM consultants to produce clash-free 3D MEP versions before creating 2D style drawings for contractors to make use of. As the consultant can also be handing over their BIM design (which is increasingly conflict free and coordinated with a extent) he/she is essentially carrying out a few of the scope traditionally taken upon by contractors. However and much more importantly, the MEP model in the consultant is not always coordinated in the manner that the services will be installed or be economical for an MEP service provider.
Though the consultants’ BIM MEP Engineered Drawings might be clash-free and spatially coordinated using the architectural and structural techniques, the 3D model provided towards the contractor by the advisor may fall short as a result of number of reasons for example: I) procurement-led changes with regard to materials and equipment; ii) it might not represent the real installation process or design; iii) the layouts might not be efficient i. e. permitting too many bends as well as connections; iv) there might not be adequate allowance for lagging; v) there might not be adequate allowance for installation/hanging; and vi) there might not be allowance for access with regard to maintenance purposes. In brief, the consultant’s 3D model might be spatially coordinated but not really adequate for installation.
Without updating the BIM model to their own fitting and installation requirements/standards, the contractor won’t experience constructability issues until within the field. At that stage it’s almost too late to create too many changes and also the installation will be compromised as overview of the model and modified drawings at that late stage will likely create additional costs as well as fees.
This additional work through the contractor is in impact repeating the modelling exercise (as well since the drawing exercise) and may be the key area of scope overlap and for that reason additional time and cost that will impact project profitability as well as schedules.
To many observers, such an overlap defeats the objective of employing MEP (M&E) BIM techniques. With more time in the beginning of the process in order to define the deliverables of every party the scope could be reduced.
There are three alternatives open to the project team to prevent scope overlap in this way. Firstly, the consultant may produce a BIM model but might not focus on creating the coordinated or clash free of charge model. He/she would make use of the model to then produce design drawings. This would provide the actual contractor with a model that isn’t coordinated but with effective routes and outlets for services that may then be fine-tuned. This method would reduce BIM modelling time for that consultant as it eliminates the coordination ‘headache’.
Next, he may create a 2D mep cad drawings as with the traditional non-BIM period. This will still permit BIM model creation through the contractor and therefore project’s need for BIM it’s still served. This method allows the contractor to produce a coordinated BIM model utilizing specialist MEP coordination companies if needed.
The third approach is perfect for the design consultants to use specialist a MEP coordination organization that understands and offers ‘coordination for installation’ abilities. By employing these skills in the design stage the output is prone to be more useful for that contractor whose role will then be to fine tune the model after which create drawings.
By managing mep coordination drawings projects using one of these simple methods scope overlap is going to be reduced and projects could be more effectively managed and delivered throughout the pre-construction and BIM phases. The end result would have been a gain for clients along with a more positive and effective utilization of BIM technology to provide MEP BIM projects.