14 May 2020
The 2 Methods of MEP Coordination
With the increasing complexity and functionality of each system, MEP (mechanical, electrical, plumbing) activities are not confined to the traditional mechanical, electrical and plumbing systems, but also include fire protection, gas piping, process piping, pneumatic tubing, data systems, etc. If we assume that the design has been created by design consultants and then handed over to ‘installation sub-contractors’, they will validate the design and value engineer the design through the process of spatial coordination and procurement of components to meet the requirements of the design.
The coordination of MEP (M&E) systems amongst themselves and with other building systems, including architectural and structural disciplines, is a critical, challenging and time-consuming task, especially in complex building projects with intense MEP requirements. The coordination process of MEP systems involves defining the exact location of each building services system component throughout the building. These are located within the constraints of the envelope defined by the architectural and structural systems. These components and systems must comply with diverse design and operations criteria, avoiding any interferences/clashes amongst building systems. Most projects require MEP coordination, without which the site installation from a ‘design only’ set of drawings would be too much of a risk. There are two ways by which the MEP coordination process takes place: 2D MEP coordination, 3D MEP coordination.
2D MEP (M&E) Coordination
In an ideal world, 2D MEP coordination can work as long as all services (HVAC design services, electrical design services, plumbing design services) and systems are assessed adequately and added to a 2D drawing. The first process is as follows:
- Design consultant creates the design.
- Subcontractors’ teams will manually update the 2D CAD drawings or develop their own set of drawings.
- Drawings will include sections and dimensions of ceiling void spaces, where systems and services will be placed.
- Dimensions of systems and heights and distances from gridlines or walls are manually added.
- Contractor ensures that each team of the services create their drawings based on the architectural ceiling void.
- Contractor attempts to visualise potential clashes manually from individual drawings.
- MEP coordination effectively occurs on site, and modifications to avoid clashes are carried out during the actual construction process.
- No automated system to identify the conflicts in the MEP system, resulting in a high degree of reliance on the intuition, imagination, technical knowledge and experience of team members to install services without experiencing clashes.
- Visualising potential clashes is difficult, due to changes in ceiling profiles.
- Understanding the impact of all building services systems and structural and architectural elements that may impede or impact a system or service route is difficult.
- A third party cannot easily review the drawings for errors.
- The design cannot be easily reviewed or communicated with a project team.
- In case of design or procurement-led changes, the process of repeating the 2D MEP coordination process becomes cumbersome.
- One of the weaknesses of 2D CAD software is that one can draw something of one size and label it as something completely different.
- As the systems and services drawings are not checked in some form of automated method, there is no guarantee that the 2D MEP coordination process will generate a clash-free drawing.
- During the time of complex projects, the 2D MEP coordination process requires multiple section viewings, which takes a long time and incur additional costs to each contractor.
3D MEP (M&E) Coordination
This process is more collaborative and allows the ability to communicate the progress of the project quickly and easily, providing 3D visuals that resemble the final system and service installation. The second process is follows:
- A clear design is created using spatial zoning, used then as the basis to start modelling the HVAC, piping, plumbing and electrical services.
- Architectural and structural models form part of the model, making it easier to insert services and systems without creating clashes.
- Once all systems and services are added to the model, clashes and other problems can be identified easily.
- Using roaming software, one can walk through the model for review.
- Clash detection software, such as Navisworks, highlights all clashes between systems and between building disciplines.
- Once identified, clashes can be corrected during coordination.
- Once the model is interference-free, drawings are created.
- 3D software allows creation of sections directly taken from the model through BIM (Building Information Modelling) technology.
- Due to intelligent 3D software and BIM coordination services, the sizes of systems are taken from the 3D model, with no chance of services or systems being modelled as one size and then labelled as another.
Beyond the coordination stage, there are several other benefits from the 3D model and CAD drawing services, including use during facilities management, energy analysis and so on.
Irrespective of the MEP coordination method used, the need for MEP coordination arises due to the lack of detailed coordination during the design stage. Additionally, the need for fabrication and installation of building systems in accordance with industry and subcontractor best practice requires MEP coordination. The 2D MEP coordination process provides a limited interference-checking capability and therefore can and will result in more problems on site, including additional re-work, change orders and inflating budgets. All of this makes 3D MEP coordination a more efficient and the increasingly preferred method for the long term.
XS CAD has valuable experience providing BIM coordination services, CAD drawing services and HVAC drafting services and plumbing drafting services for global firms. Our range of services for building services design consultants and contractors across the world include MEP design and drafting for building systems, using AutoCAD MEP, Revit MEP, Navisworks and BIM 360 Design for collaboration.