Innovating upwards

A project’s scale, combined with tight deadlines and the limitations imposed by the location, can increase the difficulties related to its development almost exponentially. “Drawing up the best plan and being able to implement it on the building site are essential. The logistical plans are worked out even as the general contractor is still being selected. Where the cranes are to be set up and the number of entrance roads as well as the possibility of using municipal land are all basic factors have to be decided if the finished product is going to be competitive,” claims Jakub Waszczuk of Porr, who is responsible for managing the construction of PHN’s SkySawa office development in Warsaw.

“The logistics team is built up as the project develops. At the start of construction, it will comprise the project manager and the construction manager,” explains Jakub Waszczuk, “and once the general concept has been established, its details are fleshed out and put into practice. Depending on the need and the difficulty of the challenges that arise, more people are then added to the logistics team. They might be needed temporarily to reorganise the traffic next to the site, to draw up a supply schedule, to organise the work schedule for the cranes or to establish specific supply times.” These days it’s not possible to organise work schedules without the use of modern tech. “We have all the documentation in our tablets, so there’s no need to carry large files of drawings onto the building site,” points out Marek Mazurek of Strabag, the building manager of Central Point, a 22-storey office building under development in Warsaw by Immobel Polska. “It’s much quicker to exchange information by using, for example, document platforms that allow several people to work at the same time,” he adds.

BIM (Building Information Modelling) is becoming much more of a common feature of the work on building sites. This allows teams to interact with a virtual rendering of all the project at whatever stage. Up to now most people have regarded BIM as just a designing tool, but it also helps during the construction process and with large projects has become a necessity. Among the large Warsaw office projects that have already been completed, BIM has been used on the Warsaw Unit (developed by Ghelamco) and Skyliner (by Karimpol). BIM is also being used in the construction of Varso Place. “Since 2017, we’ve been using BIM tools at each stage of the project. As a result, different teams as well as our subcontractors can, among other things, quickly access information about the project and the stage it has reached, find possible mistakes and correct them, as well as support tenants in the design of office installations,” points out Maciej Olczyk, the deputy chief construction officer at HB Reavis Poland. HB Reavis, in its construction work – including for its flagship Varso project – uses such innovative tools as scanning the building site to create a 3D model. “Thanks to this we can look at photos of each area of the construction, which means that technical problems can be resolved without even leaving the office,” adds Maciej Olczyk.

The road to success

Transporting building materials into the centre of town tends to require permission from the authorities, who often restrict the hours when heavy vehicles can be used for this purpose. Sometimes the traffic has to be re-routed or a road lane closed for the job. When the construction work on Warsaw Spire reached its peak, about 200 trucks a day supplied the site. Around 200,000 cubic metres of earth was removed from the excavations beneath Sky Tower in Wrocław (developed by Develia), which required 27,250 trucks – but this extra traffic was prohibited from disrupting public transport. “To avoid traffic jams we scheduled these deliveries in advance using the same logistics software that was used for Varso Place. As a result, the suppliers drove up to certain gates – there were seven of them – at a pre-arranged time. Other trucks had to wait their turn in a nearby car park we leased to act as a buffer,” explains Maciej Olczyk.

Supplying the Central Point site at the junction of ul. Świętokrzyska and ul. Marszałkowska, where the two lines of the Warsaw metro intersect, turned out to be much less complicated. “All we needed was to use a small part of ul. Zielna where it meets ul. Królewska. All the deliveries were effectively supplied via this street through one entrance to the site. In order for the deliveries to be on time, we worked out an hourly schedule, which was continuously updated. All the materials were delivered at these pre-arranged times,” explains Marek Mazurek.

Small, centrally located sites generally don’t have much storage room for the storage of materials, waste and equipment, nor for workers’ facilities. The companies involved in these projects often solve this problem by leasing neighbouring sites or buildings, or by using their own properties nearby. Occasionally, a more unusual approach is needed, such as in the case of Widok Towers in Warsaw city centre, which was developed by S+B Plan Bau Warschau and constructed by Porr. Although the project was of a smaller scale than SkySawa, the underground engineering was just as complicated due to there being both a metro tunnel underneath as well as local railway line. “The neighbourhood is densely built up, which meant that there were no neighbouring sites that we could use, forcing us to do the excavations underneath the site’s own facilities while adhering to the strictest health and safety regulations. Because of the scale of the excavations and how small the site was, we had to put these facilities on top of special circular supports,” explains Jakub Waszczuk of Porr. But such a system came at a cost. “The removal of earth from an open excavation is three times quicker than removing it from beneath a roof,” he says.

As construction work progresses, more people are recruited and new teams appear with new workers. “At the height of the work, more than 1,300 people were working on Varso Place. We set up modern facilities for them, which we had to move several times because of the lack of space on the site. This required advanced planning for each stage of the project’s development,” reveals Maciej Olczyk.

Prefab and groovy

Another useful option is for some of the construction to be carried out away from the site, by resorting to prefabrication. Construction elements and modules can be produced in factories, thus shortening construction times and making the progress of the work more predictable and less dependent on the weather. Another benefit is that less waste is produced. A prefabricated façade made out of such elements does not need to be fitted using scaffolding, since each module can be lifted to the required floor and then added to the building. “At HB Reavis we are very happy to use prefabrication. Many of the elements of Varso Place – such as the concrete stairs, the side beams, the machine walls and almost the entire façade – were manufactured off-site and supplied ready to be installed. For the construction of the Nyx hotel in Warsaw, 330 fully-equipped bathrooms were installed, which arrived at the building site ready to be placed inside the building,” recalls Maciej Olczyk. This approach was also employed for the construction of SkySawa. “Prefabrication was used for the reinforced concrete beams and the stairs as well as the concrete core – and this allowed the work to be completed in record time. A floor was added every four days,” says Jakub Waszczuk.

Known unknowns and unknown knowns

It’s one thing to organise such supplies and find storage space for them, but monitoring the entire supply chain is a completely different matter. Problems might arise with subcontractors and the producers of construction elements and one delay can lead to another. “When we were building Central Point, the most difficult period was the construction of the façade. Any delay would have resulted in not being able to complete the work on a particular floor and would have brought the finishing work to a halt,” explains Marek Mazurek.

Time is critical on a building site, but even the best laid plans can go awry. In June 2019, a fire broke out on the construction site of the Warsaw Hub, which – thanks to the 130 firefighters who were called in – did not endanger any lives or damage the structure of the building under construction. Such a situation could have put the future of the project at serious risk, but this was avoided. The fire broke out on a Friday, but after an inspection by local inspectors, the work on the site was able to resume the following Monday.

The pandemic, due to all the uncertainty it generated and the lockdowns, put many schedules at risk. Teams responsible for building site logistics also had to cope with the closure of international borders, which had a serious impact on the availability of both materials and workers. The everyday work on building sites was also disrupted. “The Covid-19 restrictions caused some disruption because new requirements had to be adhered to for disinfection, social distancing and the wearing of masks. We also had to take into account workers being absent and the work being delayed,” recalls Marek Mazurek.

Because good neighbours become good friends

Large building sites leave a permanent mark on the cityscape - they transform the skyline, but also block off natural light for smaller buildings. On the other hand, developers are investing more in green areas at their own cost, as well as benches, pavements, cycle paths and even fountains. Nonetheless, the construction period, which can last three to four years, can be very difficult for the residents of the local neighbourhood. Even the most well-organised project results in an increase in traffic, noise and the use of bright lights at night. They generate dust that is thrown up into the air that may represent a pollution hazard. Regulations also govern the working hours and noise levels, but sometimes a developer decides to go beyond the letter of the law to improve relations with the neighbours. “Before the work began on Varso Place, we held meetings with the neighbours where they could ask the managers about the current state of the work. A few hundred people turned up to these four meetings. We answered all their questions and listened to their criticisms, resulting in changes to the logistics and the overall organisation of the project – including the illumination of the buildings and increasing the street cleaning,” relates Maciej Olczyk.