Standing at 38 and 44 storeys when completed later this year, 101 George Street in Croydon uses 1,524 modules and will be the tallest modular towers in the world delivering a stunning 546 apartments in super-quick time.
Viewing the project from the nearby East Croydon train station, you recognise it as a construction job, but there is an unshakeable feeling that there is something really different about what is on display and the level of crane activity.
This is another impressive project undertaking by Tide Construction in tandem with Vision Modular who have been pushing the boundaries of volumetric modular technology in the UK (and globally for that matter) for the past decade.
Atop the two-storey basement, which houses plant and parking spaces, and the ground floor level that will feature a cafe, retail and office space together with an art gallery, you get to the modular-built residential section – a hive of activity with around 150 operatives on site, but without the chaotic feel that is often associated with traditional construction equivalents.
Groundworks started in January 2018 with approximately 500 secant piles installed around the perimeter of the site before a two-storey basement was excavated. A further 300 CFA and 1 300 bore piles between 600mm and 900mm in diameter were then installed to a depth of around 30m.
With groundworks complete, concrete specialist OBR started bringing up the 38- and 44-storey concrete slip form cores, which rose one storey per day over the course of approximately two months. For stability during the module installation phase and to ensure there is no differential movement during construction, the two concrete cores have been tied/braced together. These are a temporary solution and not essential to the completed buildings.
The modules that make up 101 George Street start on the second floor where they sit on a 1.8m thick concrete podium. The podiums were poured in-situ and created at the same time as the cores were erected, so that both were completed at the same time in January 2019, 12 months after work on the site began. To marry the traditional build element with the precisely assembled volumetric modular units required steel base plates, around 450-500mm square each, positioned on the concrete podium at the points where the modules made contact with the surface to ensure they were level to within 0.1mm.
The first of the 1,524 modules were craned into position on 22 February. There are 23 different configurations of modules being used on the George Street project, with 38 modules on every level, with apartments ranging from one to three-beds in size, which are made up of two to three individual modules each. These are delivered and installed at a rate of 10-12 modules per day.
The team is averaging roughly 1.3 floors per week and will have all the volumetric modules installed by early October.
As expected, the modules arrive on site in a remarkable state of completion. The only work required after the modules are fitted together is for them to be cleaned, connected to the building services via vertical connections with other modules and some lateral connections to the core, floor coverings to be installed and some final finishing.
Overall, the project is averaging just over 50 module installations per week, making it approximately a 32-week programme to install all the volumetric modules, which will be completed in early October. Cladding, by envelope subcontractor Century Facades, goes up as the modules rise, with installation starting roughly 10 weeks after module installation began. This is speeded up by installing bracketry within the Vision Modular manufacturing facility. The cladding will be completed around two months after the final level of modules is installed meaning that the building should look substantially complete from the exterior by the end of the year.
Overall the building is due to achieve practical completion in April 2020, just 28 months after the work began, a truly stunning achievement and one that will break the global record for the world’s tallest modular building to boot!
Speed is perhaps the most obvious attraction of the modular method, but there are environmental benefits too. The 101 George Street site fills circa one skip every two to three days, compared to around five to six you would see getting emptied every day on a traditional site of this size. Tide Construction claims this means a reduction in construction waste of 80 per cent.
The volumetric modular approach also contributes to 80 per cent less vehicle deliveries. On average 10 lorries deliver 10 modules per day. The only other deliveries are occasional ones made by small commercial vans or those associated with cladding panel deliveries, meaning a cut in CO2 of around 50 per cent, according to Vision’s estimates.
Tide and Vision Modular’s work at 101 George Street makes a compelling case for the benefits of modern methods of construction – especially the use of volumetric modular technology. Doing so much work offsite means 101 George Street is a cleaner, quieter site, and one that has yielded no complaints from the neighbours.
To see such a record breaking feat being undertaken by a UK manufacturer in the nation’s capital is truly awe-inspiring. Projects of this type open the doorway for other clients to explore this fantastic build method and for other volumetric modular manufacturers to follow suit in time.
The shear scale of undertaking and the genuinely ground-breaking speed of delivery means that the 101 George Street project is set to become a true icon of offsite technology delivery.