Making life a little easier is a win-win for everyone, especially in the complex arena of construction, which has several players. Prefabrication has been a beacon of light in the complicated maze of building processes in recent times, helping to ease the lives of contractors and project managers. Prefabricated construction BIM (Building Information Modelling), facilitated by developing DfMA (Design for Manufacture and Assembly) modelling and drawings, has opened up the way for a range of possible components and modules that can be prefabricated.
Increasingly, bathrooms, rooms and entire floors, which are sometimes referred to as ‘packaged rooms’, are being prefabricated and stacked on site to simplify procedures while saving labour, costs, time and reducing on-site accidents. ‘Packaged rooms’ are fully functional, equipped with MEP systems and only need to be positioned and attached to the mains supply of the under-construction building, and it’s easy to see why they have become popular.
During construction, bathrooms can become a labour-intensive space, as plumbing and electrical requirements are part and parcel of the design. It has been found that up to 80 percent improvement in productivity may result by using prefabrication. ‘Packaged’ bathrooms, or bathroom pods, created using the DfMA process, can be useful in buildings with repetitive design, such as educational institutes and hotels, providing consistent quality and ease of installation. It is quite possible for bathroom pods to have no, or few, defects. The factory setting allows manufacturers to experiment, research and carry out aesthetic and functional improvements.
Traditionally, all trades needed to be organised and systems were carefully laid out to conform to a bathroom design, which needed supervision and collaboration for the right procedures from plumbers, electricians, tilers, sealant applicators, interior designers, glaziers, carpenter, etc. Manufacturing bathroom pods off site has streamlined this process, resulting in reduced waste, improved quality, reducing snagging and improved performance.
Some of the considerations for the use of bathroom pods are as follows:
- Repetitive Components – Hospitals, hotels and apartment buildings can benefit to a significant degree using bathroom pods and other packaged rooms.
- Size – Bathroom pod sizes must be carefully researched, as they would need to be transported to the construction site.
- Stacking – When components or bathroom pods are repetitive throughout the design and are to be placed in the same location on each floor, installation and connection to MEP systems becomes more efficient.
- Clearance – When packaged rooms are delivered to the site, they must be raised to the requisite floor and moved into the correct position without any interference.
- Design – Using packaged rooms will need HVAC mechanical engineering consultants to make adjustments or modifications to previously planned dimensions, framing, etc. A sample bathroom pod or other packaged room can be manufactured for client feedback before orders are finalised. A self-supporting frame is required to lift and move the bathroom pod or packaged room.
- Quality Control – Manufacturing best practices can be controlled and implemented in a factory setting. Functions that are repeated can be checked and re-checked for consistency.
- Time – Manufacturers can finish manufacturing a bathroom pod while other work is continuing on the site. Using the right frames, the pods can be connected quickly to the rest of the building.
- Overheads – Manufacturing bathroom pods reduces the number of independent trade contractors that need to be coordinated to build a bathroom. Also, the amount of materials wastage, electricity, equipment to handle materials, etc. are all reduced.
- Labour – For projects in areas with high labour costs and a dearth of skilled workers, especially urban areas and remote sites, manufacturing packaged rooms is an ideal alternative.
- Installation – Installing bathroom pods is comparable to connecting a major appliance – simple and convenient. They can be placed on a special frame and hoisted to the right position.
- Delivery – Typically transported while wrapped and protected from elements of the weather on open or enclosed trucks, pods can be placed in the building prior to the construction of the external façade. They can be delivered all together or in stages for each floor or each separate section.
- Inspection – Shop drawings, MEP coordination drawings and other modular construction drawings can be reviewed by local inspectors, and delivery and installation are discussed in detail for inspection purposes.
- Connections – Before pods are placed in position, MEP systems are laid out and partition walls are installed, so that the pods can easily be connected to mechanical, waste water, water supply and electrical systems.
- Sustainability – Considerably reduced factory waste is generated compared to traditional construction methods, and waste is more controlled in a factory.
Developers benefit in the following ways by using bathroom pods or other packaged rooms:
- The complex delegation of multiple trades can be done away with.
- The product will be of high quality.
- There is a higher return on investment.
For contractors, the benefits are as follows:
- As all relevant trades are brought together in a factory, there will be fewer delays and reworking.
- In a factory, it becomes easier to follow building codes.
Inspectors may benefit in the following ways:
- Pods and other packaged rooms are built in compliance with local codes and are ready to pass on-site inspection.
- As pods arrive with open walls, it is easy to inspect electrical, mechanical and plumbing systems.
Using packaged rooms can also benefit purchasing. When dealing with hotels, hospitals, student housing, senior living establishments or multi-family housing, purchasing agents may make bulk purchases or order custom-made components for specific projects.
Packaged rooms are part of prefabricated pre-finished volumetric construction (PPVC), which is a method of construction where free-standing 3-dimensional modules are created with wall, floor and ceiling finishes, fixtures and fittings in a factory-like environment off site, then delivered and installed on site.
It is estimated that PPVC methods improve productivity by 40 percent, or 55,000 man-days. Benefits of using the PPVC method, similar to packaged rooms, are as follows:
- Shorter construction duration, saving an average of four months
- Less trade sub-contractors on site, leading to reduced crowding on sites
- Safety – few workers on site reduce the chances of work injuries, and the reduction in workers working at heights results in fewer falls.
- Eco-friendly – construction noise and dust are minimised
- Flexible – PPVC modules allow buildings to add more modules, alter existing ones and can be easily ‘detached’ for demolishing
So, prefabricated modular construction, enabled by the DfMA process, has every reason to become popular. With the right partner providing high-quality prefabricated construction modelling and M&E prefabrication drawings, manufacturers will continue to provide packaged rooms as a DfMA deliverable for the foreseeable future.
