Estimated reading time: 4 min
In the second part of our fast-track construction series, RMJM Dubai Principal, Neil van der Veen, discusses fast-track design concerns, along with measures to put in place when installing the facade and putting a solid structure in place.
Fast-tracking in high-rise and skyscraper design is more than prefabricated pods and installing a stable core. In fact, in order to fully understand fast-track design, it is important that architects and designers start to think beyond these two elements. This includes cross discipline collaboration, and inclusive, communication-centric approaches to ensure maximum results – among other strategies. In the second part of this series we will be examining key concerns which should be kept in mind when fast-tracking the facade, along with how to utilise an integrated approach with the engineering and specialist teams.
Keep the Facade at the Forefront
Fast-tracking in high-rise construction often sees the contractor focused so heavily on the floor cycle of a structure that the building is up in no time, but leaves the facade of the development lagging behind. This is massively damaging to the overall project timeline, and can result in lengthy delays. This is common for a large number of tower projects, particularly in the Middle-East. Keep an eye out for large number of concrete buildings with no facade in sight.
Where possible, architects should help guide the contractors to ensure that the facade starts to rise just a few floors from below the jump-form. If done properly, the process of closing the facade can begin and natural air can be let into the building. This is critical when starting the finishing stages on any project. Unfortunately, this is easier said than done and presents a great challenge to the design and procurement teams. The facade is an incredibly complex piece of design, both in terms of technical detailing, but also – and possibly more importantly in the long run – its performance. Once the consultant’s design is done, significant time is required from the chosen contractor to finalise their design, gain approvals, move through the required testing and mockups regime, and then commence fabrication, transportation, delivery, and installation.
Contractors must give more focus to the facade when fast-tracking skyscrapers and high-rise buildings. Time should be spent on detailing all aspects of the facade and interfaces between various facade systems. This will minimise unknowns on site which will accelerate the fast-tracking process, and overall construction efficiency. In extreme fast track scenarios, where one cannot risk any delays, the use of facade systems that have already been tried and tested as an entire system (i.e including firestopping, glass, spandrel panels, frames, cladding etc), will speed up the time between design completion and construction commencement. No matter what your chosen route, due to the manufacturer system specific requirements of facade contractors, early contractor engagement is strongly recommended where possible.
Collaborate for Solid Structural Engineering
Understanding the significance of the structural design on the encompassing architecture, and creating a system where the two can work in harmony is an essential part of the fast-tracking process. This is especially true for high-rise structures. If the design and structural engineering teams can seamlessly co-exist, then the result will exceed expectations.
Structural systems are obviously a key area of engineering with regards to both cost and speed, and the client, engineer and contractor always give significant importance to the structure for a fast-track approach. However, clients and contractors often underestimate the time required to redesign the architecture if changes are made to the structure. Again, this is why ongoing collaboration and open communication across all areas of the development is essential.
Some structural systems have the ability to alter a space altogether. For instance, changing from a concrete-edge beam to a steel system typically renders the area near the facade irreparable. The steel beam is ironically likely to end up deeper and located further within the space itself, when compared with the concrete alternative. This is especially likely to be the case if it is a last-minute value engineering exercise.
Other important areas to consider include agreed floor loadings, and the overall weight on the structure. This is crucial in relation to the engineer’s calculations, so any changes in weight must be communicated effectively to them. Changes in relation to wall construction, density, weight, or screed construction, can substantially vary the weight of the project – especially when multiplied over so many floors. But being too conservative in one’s assumptions adds cost to the structure. Trying to value-engineer these systems to improve cost or speed can potentially have the opposite effect, so collaboration here is essential.
Ultimately it comes down to adopting an effective, integrated and collaborative approach. Working closely with all consultants, contractors, the cost team and the client will lead to an understanding among players and drivers, and will ultimately deliver the best overall system to balance each individual need.
Fast-tracking in the construction industry requires detailed knowledge of different design elements. Additionally, it calls for effective planning, integrity and an emphasis on the value of a collaborative approach. What do you see as key issues when it comes to fast-tracking the facade and structural process?