If your building design philosophy is ‘First Time Right’ and you firmly believe in ‘Prevention is Better Than Cure’ than you will appreciate the value that BIM-based MEP (building information modelling mechanical, electrical and plumbing) coordination (also known as design collaboration) process can bring to a design and construction project.
In this article, we discuss the entire MEP coordination process and share a Downloadable Checklist (Design Coordination & Drawing Review) and Downloadable Infographics (MEP Coordination Workflow & MEP Dashboard) that can be used for current or upcoming design and construction projects.
 Approaches for design coordination of a construction project
 Traditional approach
Traditionally MEP coordination is conducted through a “sequential comparison overlay process” (Riley et al. 2005; Khanzode et al. 2008; Korman and Speidel 2010). In this process, the functional design is prepared by a consultant engineer, while the detailed design for each trade is developed by specialist contractors. The specialist contractors sequentially compare their shop drawings at the same scale on a light table and try to identify potential conflicts. Obviously, this manual method is costly, time-consuming, and inefficient.
When computer aided design (CAD) was introduced, designs were made in a 2D model, in this method, there is no automated system to identify the clashes/conflicts in the MEP system and therefore there is a high degree of reliance on the intuition, imagination, technical knowledge, and experience of the team members to put out the services without site teams experiencing clashes.
 BIM-based approach
The BIM-based (3D modelling) approach modernised the design process by providing a virtual 3D model of the building which can be developed before the actual construction begins. This virtual model delivers speed as well as convenience - making design changes in a virtual model is easier. You can easily alter any part of a 3D model, eliminating the need to redraw the design again and again. Also, the 3D model shows the clashes/conflicts between different trades/disciplines.
The BIM-based approach during MEP coordination facilitates collaboration among all discipline specialists (includes mechanical, electrical, plumbing, structural and so on , so they can share comparative data and necessary interdisciplinary information with each other. BIM allows for the simplification of many tasks and considerable savings both in terms of money and time.
With respect to MEP coordination, the traditional design process relies on the completed design from all project participants (trades/discipline), while in the BIM-based approach it starts in the earliest form of the design development process stage.
- 3D MEP preliminary design model (LOD 100)
- 3D MEP detailed design model (LOD 200)
- 3D MEP construction design model (LOD 300)
- MEP construction model (LOD 350)
- MEP prefabrication model (LOD 400)
All designs start with sketches and move to 2D drawings (Autodesk’s AutoCAD widely used) and then advances towards the 3D model (Autodesk’s Revit widely used) in the case of BIM-based design approach.
 About building design systems
- Architectural system – Indoor and outdoor separation: wall, fenestration, roofs
- Structural system – Elements providing static equilibrium against gravity and dynamic loads
- Building services – HVAC, electrical, plumbing, vertical transportation, and life safety systems
- Interior systems – Occupied space encompassing partitions, finishes, lighting, acoustics, and furniture
- Site service – Landscape and support systems for the building, including parking, drainage, vegetation, and utilities
Building service systems are the active building systems and include mechanical, electrical, and plumbing (MEP) systems. Building services must fit within the constraints of architecture and structure and must meet the expected performance regarding comfort and safety. Building systems moderate the building environment, distribute electric energy, allow communication, enable critical manufacturing process, provide water and dispose of waste, and provide critical resources for life safety as mentioned in Korman 2008.
 What is MEP Coordination?
Mechanical, Electrical, Plumbing (MEP) and Fire Safety (FS) coordination (MEPFS) is the practice of multi-disciplinary collaboration of three major design verticals of any building infrastructure, which are architecture, structure (beam, column, torsion, etc.) and MEP designs.
The active systems are fundamental components of any building, and have been estimated to cost up to 60% of the total cost of the building projects as per Korman and Huey-King 2013. Mechanical, Electrical, and Plumbing (MEP) coordination is one critical activity and an important part of the constructability review process. Three knowledge domains are required for MEP coordination, namely, design, construction, and operations and maintenance.
- Mechanical System – HVAC Equipment and distribution such as cooling tower, AHU, ducting, etc.
- Electrical System – Panels, switchboards, elevators, transformer, cable trays, etc.
- Plumbing and Sanitary System – Pumps, water holding tanks, pool filtration equipment, Sump, sewage pit, grease and sand traps, etc.
- Fire Safety System – Fire sprinkler pumps, sprinkler tanks fire shutter, smoke curtains, piping system, etc.
- Outside of Building – External works, rooftop, and external face of a building, etc.
To keep the harmony between these separate designs, it is essential to have a coordination of updated designs of each discipline. Each discipline must be precisely aware of the locations of other installations during the modelling phases and this can only happen when the latest, most precise version of each MEP’s master plan is made available. It may be that these designs have collisions or clash in some locations, where one or many components are occupying the same space. It is crucial to understand these clashes at an early stage of the construction project.
MEP coordination is about synchronizing all the building services with other disciplines that form the building fabric, structure and external envelope (steel, concrete, etc.). Mostly the professionals conducting the coordination process focus on highly congested spaces within the structural systems to prevent building service systems interference.
This technology-based approach for coordination offers multiple advantages as communication and collaboration begin at the 3D modelling stage itself. MEP BIM 3D modelling services typically come in the later stage after the architectural BIM and structural BIM models have established the premise for an MEP BIM model.
Fundamentally, BIM not only resolves the structure coordination and modelling difficulties, it helps coordination between teams, contractors, fabricators, consultants and engineers to build up a consistent communication channel.
In the BIM-based approach, MEPFS 3D coordination modelling (Autodesk’s Navisworks widely used), highlights clashes within MEP systems against other MEP systems or MEP systems against structural, integrates each team’s designs andensures there is harmony
At this stage, BIM modelling service providers can help in MEP coordination. Once they run the clash detection process, they have a clash report showing possible collisions at multiple locations with reference positions in the coordinated design. After locating and analysing the cause of the clash, the required design changes can be made.
MEP coordination starts in schematic design (SD) phase and it has to be completed before the construction documents (CD) phase. Usually, the general contractor holds a gatekeeper meeting where all disciplines are involved and collectively they review clash reports.
 Step 2: Architectural Model Validation
Verify the coordinate of the architectural model. It is important to have the same coordinates for both MEP and architectural models before linking them. The best approach is to use the “origin to origin” positioning option for placing both models.
Prepare MEP model each of the disciplines/trades – mechanical (HVAC etc.), electrical, plumbing and include all elements before linking them for coordination with other sub-disciplines within the central file.
- Level by level (story by story)
- Room by room (below raised floor)
- Horizontal space (plenum)
- Vertical space (core shafts)
- Mechanical system – HVAC equipment and distribution, ducting, etc.
- Plumbing and sanitary system – Pumps, water holding tanks, pool filtration equipment, sump, sewage pit, grease and sand traps, etc.
- Fire protection system – Fire sprinkler pumps, sprinkler tanks fire shutter, smoke curtains, piping system, etc.
- Electrical system – Panels, switchboards, elevators, transformer, cable trays, etc.
In this step, we can know the ID of the element that clashes, and fix it in the Revit file. Once all clashes/conflicts are solved in the Revit file, export it again, with the same name and in the same folder. When you reload the cache in the Navisworks, resolved clashes will appear in the yellow in the “Resolved Section”. If any new clashes emerge, they are classified in red as new.
- Korman, T., Simonian, L., & Speidel, E. (2008). Using Building Information Modeling to improve the mechanical, electrical, and plumbing coordination process for buildings. In Proceedings of the AEI 2008 Conference, Colorado, USA.
- A thesis by Babatunde Adewale on the topic “A framework for the process of effective coordination of building services during the design development and review stages.”
- Building an essential guide for MEP consultants by Building and Construction Authority.
- Integrated Buildings: The Systems Basis of Architecture by Leonard R Bachman.
- American Institute of Architect Pittsburgh in its community article has separated the building design process into multiple phases.
- MEP Coordination in Building and Industrial Project by C. Bob Tatum and Thomas Korman