The Rise of MEP Risers as a DfMA Deliverable

3 March 2020

Shalini John

Design for manufacture and assembly (DfMA) has been weaving a spell in the AEC (architecture, engineering, construction) industry for some time, and it has been especially potent in the delivery of MEP (mechanical, electrical, plumbing) risers for construction. The magic of DfMA lies in its ability to bridge the gap between the challenges of manufacturing and assembly of products to provide sound solutions that save time, money and potential accidents on site. Increasingly, HVAC (heating, ventilation, air conditioning) mechanical engineering consultants are turning to DfMA as a fast, cost-effective delivery option for MEP risers. There are several reasons for this.

Firstly, though, what do we mean by a riser and, specifically, an MEP riser?

Much as the name suggests, a ‘vertical’ riser refers to anything rising vertically in a building. An MEP riser involves riser ducts, pipes and conduits.

Vertical Riser Ducts

MEP pipes and cables are unattractive, so people prefer not to see them, and housing them in vertical riser ducts is a solution.
Riser ducts which are placed correctly to reduce pipe lengths and cable runs can minimise costs.
Sanitary waste pipes should ideally avoid bends, thus ducts with pipes must travel in an unhindered vertical path through a building.
Riser ducts travel through floors and must be fire-protected, as voids in the system may present a route for fire to spread.

Vertical Riser Cables and Pipes

Placed within ducts, cables and pipes that travel through floors have fire-protected collars to prevent fire from spreading from one floor to the next.
Within riser conduits, cables are connected to sockets and light fittings mounted on walls and columns.

Wet and Dry Risers

Positioned next to stairs, wet or dry risers run through the entire height of the building and deliver a direct feed of water to each floor, which is invaluable in times of fire.
Dry risers have a ground coupling pipe placed on an exterior part of the building, so that fire services can connect it to a water supply.
Wet risers are directly connected to the building’s water mains supply.

The DfMA process involves products being designed, manufactured, or prefabricated, and assembled in a factory or factory-like setting and then being transported to the construction site to be placed or set correctly into the building during construction. When the said products are MEP risers, there are several significant advantages that may ensue. Some advantages are that when MEP risers are assembled off site during the DfMA process, it can lead to faster project completion, improved worker safety and savings in expenses. There are other advantages also.

Benefits of MEP Riser Prefabrication

MEP riser assembly can begin off site, without waiting for a ready site or site approvals.
In DfMA, there is less work and the work will be completed faster, saving costs.
Scaffolding work is reduced. Site labour, such as moving, lifting and assembling is also reduced, resulting in improved worker safety.
When prefabricated MEP risers are installed, many connection problems are eliminated, and the work on site may be as simple as connecting risers to the mains. This reduces the potential for components being damaged during assembly on site.
Needing less manpower, prefabricated risers can be easily and efficiently installed.
Prefabricated MEP risers result in reduced dust, noise pollution and on-site debris.
Quality control is ensured, as most of the work is conducted in a controlled environment.

As a result of delivering MEP risers to construction sites promptly, factory congestion and component damage is reduced. In addition, using Building Information Modelling, or BIM, it is possible to simulate on-site installation in advance and thus identify and rectify possible problems. To do so, builders are required to share precise data, such as scheduling, crane capacity, availability of equipment to place the risers on, routes of delivery, etc. with other project stakeholders.

Following the delivery of prefabricated MEP risers to the site, engineers may carry out inspections before installation and connection to the mains. There is an optimisation of logistic coordination, and it is easy to maintain the sequence of work using BIM technology or BIM coordination services. With the right global MEP prefabrication services provider using BIM, who is well experienced in delivering high-quality DfMA modelling and drawings, it becomes a cost-effective option for Western firms to use BIM technology.

So, how does using prefabricated construction BIM benefit the DfMA process to deliver MEP risers?

Well, here’s how:

It becomes easier to design MEP risers using BIM, leading to a reduction in the number of components, tools and manpower needed for assembly.
Prefabricated risers follow a prescribed process with BIM and are unaffected by weather.
Using BIM MEP services in DfMA helps reduce the number of required riser interfaces, thus reducing the amount of required data and assembly time.
With BIM, vertical assembly and self-aligning parts (don’t require adjustment or reorientation) can be designed and tested accurately so that risers can be manufactured in a shorter time.
BIM helps design and model fewer parts for interconnections in the DfMA process. Interconnected parts can connect two other parts in a riser, and harnesses help ensure that connectors avoid misalignment. The result is that several solder and cleaning steps can be avoided.
Modularisations and standardisation characterising DfMA can be optimised using BIM, as BIM facilitates the delivery of prototype specifications, thus enabling comprehensive testing. This results in reduced risks, and risers can be reconfigured and transported.
Modifications, improvements and standardisation of risers can be continuously performed using BIM, improving quality and efficiency.
Using BIM, the process of DfMA can be corrected, and design teams can be better informed and can select the appropriate technology and sequences.
With BIM technology, wastage is virtually eliminated or reduced considerably and so is the challenge of material and labour shortages.
When site logistics are complex, with limited space and limited access (eg. airports), using BIM technology in DfMA takes care of materials and labour without using space on the site.
DfMA can help provide risers for projects with repetitive elements, such as schools, hotels, hospitals, colleges, malls, etc. Once the riser design is finalised, it can easily be replicated in large quantities using BIM.
Using BIM in DfMA simplifies the manufacturing process of risers. Inspection, testing, assembly, purchasing of components, redesign, etc. are all streamlined.
Using and identifying the location of multifunctional parts in risers using BIM allows one part to execute several functions and simplify the process.

It seems clear that delivering MEP risers through DfMA is a more productive process of construction than the traditional on-site method, especially using BIM technology, due to time and money saved while maintaining high-quality output. Inventory, problem identification and solving of challenges associated with riser manufacturing is simplified with prefabrication. Also, DfMA enables an improvement in maintenance and servicing processes.

Smooth material flow, reduction of material transport, controlled processes, multiple simultaneous operations, etc. are enabled with DfMA and ably assisted through the use of BIM technology. So, DfMA benefits project stakeholders in the areas of cost, speed, testing, efficiency, safety, site space, environmental effects, all while simplifying processes for riser manufacturing and assembly. By comprehensively understanding the brief, specifications, constraints, MEP systems and with the aid of high-quality M&E prefabrication models and drawings, the rise of MEP risers as a DfMA deliverable is bound to continue.

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