At the heart of any construction project is a beating, vibrant group of systems essential to the efficiency and comfort of the building — MEP systems or building services. Mechanical, electrical and plumbing (MEP) services are vital to the functioning of a building, and their efficiency is dependent on the design and installation of these services. Traditional methods of MEP installation have received a boost with the arrival of BIM (Building Information Modelling) practices, but is that as far as we can go? Robotics is slowly inching its way into MEP installation practices and may progress to impact more areas of the MEP installation process in the future.
So, how does MEP installation work now?
Designs and drawings are generated from architectural layouts with the purpose of obtaining permits and for MEP contractors to study, three weeks to three months before construction begins. Then, MEP engineers, MEP contractors and workers are hired. It is crucial to find the right team in terms of experience, expertise, familiarity with the location and style of building and those who can work within budget. After the lot is cleared and the foundations are laid, it is time to install mechanical, electrical and plumbing components according to the MEP layouts prepared.
Meetings are conducted with clients to finalise the location of ducts, lights, switches, fixtures and pipes. Last-minute requirements are liable to crop up, such as an electrical outlet or automatic water valve. Typically, these MEP system designs in 2D were created using CAD software, providing basic and somewhat limited information. That was before Building Information Modelling (BIM) arrived on the scene.
In the current scenario, the BIM process is extensively used in the West and parts of the Middle East for improved collaboration and MEP coordination. The use of MEP BIM helps create 3D models with critical MEP system information. The data hosted in a BIM model is contributed by construction engineers, survey engineers, civil engineers, electrical engineers, mechanical engineers, designers, architects and even the building owners. Thus, the final 3D model has a wealth of relevant construction data that is useful for both decision-making and clash-free MEP coordination. Within the ambit of the BIM process, each pipe, conduit, duct and hanger can be represented in digital form using 3D software.
This practice reduces costs and increases the efficiency of MEP installation.
The future is bright with possibilities in the context of MEP installation, and part of that future has already begun. Along with the revolutionary adoption of BIM processes worldwide, futuristic technological advances are becoming affordable and being put into practice in our present, primarily 3D printing, unmanned drones and robotic construction methods.
Before the widespread use of BIM technology, up to 25 percent of ductwork installation on site consisted of marking and placing hangers. Traditionally, two men can mark 100 hanger positions in one day.
Now, with the help of BIM processes, a new development has occurred — the rise of the robots. Well, not literally and not as dramatically, but the use of robotics has made an impressive debut on the construction scene. Trimble has developed the Robotic Total Stations and specialised Field Tablets to precisely locate hanger positions. Using digital coordination drawings and BIM modelling sent to equipment on site, Total Stations uses lasers to find hanger positions based on two previously established zero points. With this method, a single person can control the robotic station to mark 350 hanger positions in a day, which works out to an 85 percent decrease in labour expense for each hanger and works out to be 3.5 times more efficient than the traditional method. The precision of the marked positions reduces delays traditionally experienced during ductwork, plumbing and electrical installation, resulting in cost and time savings.
BIM technology introduced accurate models into the process of design, particularly useful for MEP engineering design and installation. These processes developed further, using 4D and 5D BIM, which take into account site constraints, such as equipment capacity, working methods, time and material schedules. They needed a live link to the site. Robotics Total Stations provided a solution by enabling the tracking of work on its completion and referencing this against the original model. Changes can be made as and when required, and the tracking of completed work helps a smooth progression to the next stage of the process.
Currently, this state-of-the-art technology is expensive, but it has been shown to save time and money in the long run. The Robotic Total Stations, or RTS, method can help overcome some of the limitations presented by the traditional ‘tape measure, spirit level and theodolite’ method.
Placing the components of building services layouts in position has traditionally involved a team of workers who refer to building drawings. They use tape measures, spirit levels and theodolite to pinpoint locations for pipework, cable trays and other MEP components. Complications arose when dealing with complex structures, those that involved curved walls, prefabricated materials and components and non-traditional spaces. Errors resulted from:
- Identifying the right reference point
- Ensuring that the tape measure is stationary
- Ensuring the string is stationary on curves
- Keeping the theodolite level
- Ensuring the precision of angle measurement
Even minute errors could result in potentially dangerous or expensive outcomes. An example would be an error in angle measurement which would mean that prefabricated components could not fit in the spaces they were designed for. Errors in service layouts can cause clashes with other building elements or the services themselves, culminating in rework and wasted time, materials and finances. The traditional approach is painstaking and long, with any delay affecting the work of other stakeholders.
Using the RTS method, only one person is needed to complete a services layout rather than the traditional team of workers.
How does this happen?
A tablet with the right software can be loaded with MEP 2D drafting or 3D building models. This controls the RTS. The model helps identify site survey points, which then locates the RTS on the site and on the model.
After identifying the RTS and its location, the RTS operator can look at the model on the tablet and choose points to be marked.
The RTS accurately informs the operator of the distance between it and the point selected. The operator is guided to the point by the RTS that issues directions, such as forward/backward or left/right. The operator can then place a stake in the mark and move to the next one.
Advanced RTS features include Visual Layout, enabling a laser to mark the point, so a stake need not be used. This is useful in the precise positioning of several trades simultaneously, resulting in minimal delays on site.
Benefits of RTS
- Increased efficiency
- Using the same drawings or models for all trades, collaboration is easier and faster
- Improved accuracy
- Layout points are accessed from the model and layout position changes can be recorded and documented with data such as informative reasons and photographs
- Minimal errors, since the RTS works from the model. No manual measuring is involved though points are accurately marked and the tablet references the points’ purpose to the operator
- Reduced paper work, no risk of losing documents
- Reduced costs — only one person is required as operator, which improved productivity by five times
- Improved quality control
Challenges of RTS
- Expensive initial investment
- Companies without layout teams foresee less ROI
The good news is that RTS technology is relatively simple, simple enough for any MEP team member to mark accurate layouts so that the workforce is used in a more productive manner. A significant amount of time is saved, thus reducing the number of workers required and the consequent labour costs.
Savings with RTS
- Minimal rework with increased QC/QA documentation and recording — cost reduction
- Increased on-site efficiency — labour cost reduction
- Minimal MEP component location errors — cost reduction
During installation, MEP designs tend to evolve, although for large-scale projects, it is essential that MEP installation drawings are finalised early on, especially in the BIM environment. This is crucial to clash detection, so that one MEP element does not interfere or clash with the placement or process of other MEP elements from different services, clash detection can be achieved with detailed MEP coordination drawings and 3D models.
Robotics has also made an entry to the construction industry in the form and use of drones, something many refer to as robotic vehicles. Drones have forayed into various construction roles, namely as inspectors of pipelines and cell towers and taking aerial views of construction sites. With the help of special cameras, including infrared filters or gas leak-detecting sensors, drones can gather multi-layered information while eliminating the costs and risks associated with humans trying to reach difficult and dangerous areas. Multiple propellers add stability to drones, thus enabling them to obtain accurate information. High-resolution cameras, laser scanners and gyroscopes on drones can be attached to quad-copters for highly accurate data gathering. Drones have even been used to inspect solar panel array installations.
A real-life example of the use of robotics in MEP installation can be taken from 2015. A company in the Middle East was engaged to install MEP systems and services for an office tower, a hotel, a residential tower with basement parking and a podium. Using BIM processes, a BIM model was generated and a new method of construction was employed to save labour and other costs. Trimble offered Trimble Robotic Total Stations (RTS) with Trimble Field Link as MEP construction software.
The Trimble team of a junior engineer and two operators fed support points to the software through their model using Trimble Field Link and RTS, and the operators marked points on the site while the engineer ran the RTS. A total of 210 points were marked in 4 hours.
Three teams of 3 installers each were also used traditionally to manually find support points from 2D drawings with measuring tape, ladders and scaffolds in the same project. It took this team 48 hours to mark 156 points.
So, BIM data can be transferred to a site and used as a base for robots to find locations for hangers, anchors and sleeves quickly and accurately. Robotics can also be used to mark electrical boxes and drainage moulds, among many other functions. Though the first step towards investing in robotics for trade contractors may seem expensive at first and requires careful thought, the use of RTS in MEP installation has exhibited a tendency to save time and money while ensuring accuracy. Trade contractors stand to make significant profits in the long run.