Marsh Wall, London Docklands

An ambitious project in London's Isle of Dogs is set to deliver one of the tallest modular buildings in the world. EPR Architects came up with the scheme to build a 48-storey accommodation block for students using modular pods manufactured offsite. The innovative plans, submitted by Tide Construction, have now been given approval by Tower Hamlets council in a 7 to 1 majority vote. 

Situated at 30 Marsh Wall, the building will house over 1,000 studio apartments with a roof garden and four amenity levels. Tide is also the firm behind the two towers in Croydon, which previously held the record for the tallest modular building, standing 38 and 44 storeys high. Tide is already involved in the construction of a third tower, which at 50 storeys, will eclipse even Marsh Wall. 

The technique involves creating prefabricated pods which are carried to the site and stacked on top of each other, making the construction process more a matter of assembly. Marsh Wall is particularly well-suited to this modular process because it will occupy a heavily restricted triangular site that would cause immense logistical and access problems for conventional construction.

In addition to the practical benefits of modular construction, there are significant environmental advantages. Because the manufacturing work will take place offsite, the amount of construction waste is expected to be reduced by 80%, and 98% of this will be recycled.

The planning application process was by no means smooth, with various objections raised. The choice of site was called into question since the only nearby university buildings are the small London outposts of the Universities of Cumbria and Sunderland. Others complained of the aesthetics of the design. In the end the vote, on the recommendation of the planning officer, won the day and marked a major advance in the popularisation of modular construction methods.

The modular contractor on the project is Vision modular, the structural engineer is Barrett Mahony Consulting Engineer, the planning consultant is Rolf Judd Planning and the landscape architects are Spacehub Design.

Modular across the water

Another exciting project highlights the advanced state of modular technology. The 880 metre Thame Valley Viaduct for HS2 near Aylesbury will be entirely prefabricated and assembled on site. The design is the work of EKFB, HS2 Ltd's main works contractor, who drew up the plans in collaboration with architects Moxon and ASC, a joint venture between Arcadis, Setec and Cowi.

The viaduct will be built in 36 spans of 25 metres each, and will cross the flood plain and the river just three metres above the ground. The 35 supports will also be made off site. According to HS2 Ltd, modular prefabrication will reduce the carbon footprint of the construction project by over 60%. Tomas Garica is head of HS2 Ltd's civil structures, and he stressed the importance of this factor in HS2's decision to go modular: "HS2 trains and stations will be zero-carbon from day one, providing a cleaner, greener way to travel and helping the fight against climate change. But we're also serious about reducing the amount of carbon we use during construction, and Thame Valley is a great example of how our contractors are using the latest engineering techniques to do just that. Prefabrication and offsite manufacturing offer huge benefits in terms of efficiency, and this design will help us deliver a more efficient, durable and elegant structure with less concrete and steel."

HS2 and its contractors are now looking at other sites where modular technology can be used in viaduct construction. As EFKB's technical director Janice McKenna says: "The techniques used in the Thame Valley Viaduct are also being used in other structures along our line of route."

The project is a significant step forward both for the design of viaducts and for modular construction in general. It further demonstrates the benefits in terms of cost-efficiency, safety and environmental responsibility.