Understanding How to Create Prefab MEP Modules for Hospitals

Posted by Kuldeep Bwail on March 27th, 2020

Emergency services, such as hospitals and other medical facilities, are essential to modern life, and that means that it is necessary for their design and construction, especially the design of MEP (M&E) systems, to be as near flawless as humanly possible. Creating prefabricated MEP modules to use in hospitals has several advantages, one of them being that each unit will have a consistent design wherever it is used throughout the hospital building, enabling easier functioning of the services and ease of maintenance. Hospital building services design and building services coordination can be perfected by using professional and precise MEP (M&E) prefabrication models and drawings as well as using MEP coordination drawings. Let’s look at how these prefabricated, or prefab, MEP modules need to be developed for hospitals.

Design for manufacture and assembly (DfMA) is another term that is commonly used for prefab design. Thus, it is also possible to use DfMA modelling and drawings to help design prefab MEP modules. These modules consist of individual units of prefabricated MEP systems, MEP components and other equipment, which are all integrated as a sub-assembly at a factory or other location off site and then transported to the site to be installed in the building under construction.

Why would anyone want to do that? Well, there are a few good reasons.

Benefits of Prefab MEP Systems  

• Increase in productivity
• Saving time up to 60%
• Improvement in on-site safety
• Time spent working high above the ground is reduced
• Decrease in environmental degradation
• Minimal dust and noise on site, as most of the work is executed off site
• Improvement in quality control and quality assurance
• Improvement in quality of MEP assemblies, as components assembled in a factory  

The detailed benefits of prefabricated construction modelling are:  

• Being Eco-friendly

Any extra materials during construction can be recycled in-house. By using accurate design drawings, air filtration is improved and the joints are tighter, resulting in effective wall insulation and increased energy efficiency.  

• Constructing Faster

Since MEP modules are assembled in a short period of time, construction time is also saved. Multiple modules are created at the same time and delays with subcontractors are eliminated. Prefabrication can begin off site early.  

• Reducing Costs

Material suppliers sometimes offer bulk discounts to prefabrication manufacturers.  

• Adaptability

Using modules allows project design to be flexible. Modules with a flexible flatpack design can be used in cramped spaces.  

• Reliable Quality

Modules are built to a uniform quality. All the services are supported and clearly installed. Off-site manufacture means early testing, commissioning and project assurances.  

• Minimising Site Disruption

Making modules in a factory helps reduce frequent trips, traffic congestion and the number of personnel. The pollution, waste and noise on the site is reduced, increasing productivity. Components of service systems are not damaged by those working on other systems.  

• Safety

Workers face reduced health risks associated with weather and are also less prone to accidents. Injuries are prevented due to reduced high-heat tasks in restricted areas and minimal scaffolding work.  

• Repetition

Prefabrication is useful in spaces with calculated repetition. Hospital bathrooms and room head walls are good examples. Bathrooms and rooms are repeated many times in a hospital and can be served well by using prefab technology  

So, what does an MEP module consist of?   

An MEP module typically involves an integrated system of steel frames, pipes, ventilation ducts and cable trays. Examples would be corridors, risers, bathroom pods and walls. Modules can be from 6 to 12 metres in length. To correctly design an MEP module, the services must be coordinated, the most suitable method of connecting the modules must be determined and the size and weight of steel beams for mounting frames has to be calculated.  

The MEP modules are assembled in a workshop or factory situated off the construction site and then transported to the site for installation. Duct lifters, chain blocks or tower cranes are used for the modules’ installation.  

A prefab MEP module for a riser or ceiling corridor includes MEP services assembled in a factory. The required ‘plug and play’ technologies with pipework, cables and ductwork are installed in the modules, and they are then mounted in the ceiling or beneath the floor in plant spaces or service risers. Pipework systems and electrical cables are pre-assembled in the factory, carried to the site and then connected to the mains. Installing MEP modules using BIM technology minimises rework and the re-design of services, helps detect clashes and helps make modifications quickly or at the early stages. Prefabricated coordinated drawings that include supporting frames, flanges and corners are also called MEP shop drawings. These drawings are necessary to create MEP modules.  

On completion of the MEP shop drawings, a jig or template is utilised to check the alignments of the module. Shrink wrap or tarpaulin can be used to cover the modules and protect them from the effects of weather. Castor wheels can be used to transport the modules to the site for its installation. At the site, pallet jacks, scissor lifts and forklifts raise the modules and put them in the right place.  

To ensure a seamless process of prefabrication during both the design and construction phases, there are certain considerations to keep in mind. They include the following:  

• Contractors and MEP specialists are consulted early on

When MEP specialists and contractors coordinate MEP services early in the process, the service distribution can be optimised. Contractors can improve the quality of work, in spite of site constraints, and reduce the waste of materials on site by using Building Information Modelling (BIM).  

• Managing the site/project

Delivery routes for prefab MEP modules and their lifting equipment must be planned early on, since modules can be heavy and bulky. Correctly calculating the time for the transport and weight of the modules can facilitate faster installation and eliminate inefficiencies in site management.  

• Replacement, renovation and maintenance

The placement of valves and space around modules must be considered for maintenance needs and need to be included in the prefabrication drawings.  

• Compliance to codes and regulations

The relevant project stakeholders must ensure that the installation of prefab MEP modules must comply with the local code of practice relevant to each system.  

When fabrication uses BIM technology, integrated workflows can be created. Prefabricated construction BIM is useful in hospitals. Specifically for healthcare buildings, there is a growing interest in bathroom pods for a prefabrication approach, as it has the potential for considerable cost savings. The design of MEP modules may be affected by prefabrication, such as wall framing, MEP system routing, interstitial space layouts and the position of headwalls.

With so many features involved, it is important to test the modules, especially bathroom pods.

As part of the testing, the toilet, faucets and shower should be hooked to the mains. The lights and other electrical elements should be checked as well. If the trench drain along the edge of the shower is causing problems, the trench drain cover should be replaced to allow increased water flow.

Early Design Decisions

Hospital managements and the design team must work together closely to come to early design-related decisions when using prefab MEP modules, such as wall colours, faucets, floor styles and wall textures. When these stakeholders are still looking at the MEP shop drawings, RFIs can be submitted which enquire about mechanical components, colours and product specifications.  

Component Connections

While installing bathroom pods and headwalls in a hospital, the teams may have to work in tight spaces. When the connection points in a prefab MEP module are placed in such a way that they do not take tight spaces into consideration, the installation of bathroom pods and other modules can be even more difficult. This could lead ultimately to schedule delays and installation issues.  

A BIM model can specify connection locations and working conditions. Bathroom pods should have as many connections near the edges of the module footprint as possible to keep the work needed around the pod to a bare minimum.  

Code Compliance

Dimensional issues of prefab MEP modules can be minimised by verifying the parameters decreed by local building authorities.  

In a documented case involving the installation of 120 prefabricated bathroom pods at a hospital, the following observations were made:  

• Each unit required just two hours for installation.
• The time taken for the project schedule was reduced by two months.
• There were no installation complications, no broken mirrors and no cracked grout.
• Only one subcontractor was used instead of eight.
• The plumbing and electrical hooks fit seamlessly.
• All 120 pods were 100% dimensionally consistent.  

The building services coordination process for hospitals is critical. In addition to the general MEP services associated with any building, hospitals generate a large amount of solid and fluid waste that must be disposed of in a timely, hygienic and efficient manner. All the building services can work together effectively when the preconstruction design includes accurate MEP coordination drawings. Using prefabrication, especially prefab MEP modules, can enhance the effectiveness of the design. Experienced, precise and technically qualified professionals are required to develop MEP (M&E) prefabrication models and drawings or DfMA modelling and drawings. Increasingly, Western firms are looking to India to provide this kind of expertise. With the right offshore partner to help design prefab MEP modules, many Western firms will be inclined to consider the merits of prefabrication construction.