Looking from the Tower of London towards Tower Hill, the former execution site where many famous Britons found their early end, you will probably not expect to see a modular building: the citizenM Tower of London hotel. Logically, because modular building is usually associated with cheap catalog architecture and not with an iconic building in such a prominent location.
Modular construction is becoming increasingly popular because it offers a solution to a number of persistent problems in the current construction industry. The speed of construction is usually named as its main advantage because this building method can shorten the construction time by 50%. This is partly because all hotel rooms, as in this case, are pre-assembled and inspected in a factory, including the complete interior and the technical installations. As a result, many of the frequently occurring building defects become a thing of the past.
The lack of available skilled labor at the construction site also tips the balance in favor of modular construction since much lower staff numbers are required on site.
The list of benefits is a lot longer, but still modular construction is only applied on a limited scale. This has to do with the relative unfamiliarity of this building method with many clients, architects and builders. In order to be able to utilize the full potential of modular construction, a good understanding of the preconditions is necessary. It requires a fundamentally different way of designing, planning, building and even financing real estate projects.
Next to that, there is the persistent prejudice that modular buildings are only suitable for temporary construction and, moreover, that they are unsightly.
The new hotel that I was going to develop with my team during my time at citizenM would be located opposite the Tower of London and in view of Tower Bridge. And also right next to one of the last remaining parts of the London Roman Wall and to Trinity Square, the place where the British commemorate their dead of the fishing and merchant fleet who fell during two world wars.
Surrounded by 2,000 years of history, our hotel would be located in the middle of a delicate Unesco World Heritage Site. In addition, the exit of the Tower Hill Underground station was on our lot and would become part of our new building. With more than 40,000 passengers a day, Tower Hill is London's busiest underground station and therefore had to remain open during construction. One of the conditions of our building permit was that we would refurbish this station and provide two lifts directly to the platforms.
To achieve an approved design for this site, we had to reach agreement with a large number of stakeholders. Our neighbors from Her Majesties Royal Palaces, the historians of English Heritage, the city architects of The Commission for Architecture and the Built Environment, the traffic commissions and licensees of the City and the Borough of Tower Hamlets, the London Underground and many others. We had to convince each and every one of these professional organizations that a modular building at this location would bring a number of serious advantages.
A fast construction time is positive for the neighborhood. Also, a modular building weights less than a traditional building, which means a lighter foundation would suffice. This is an advantage at a location surrounded by historic buildings and undermined by metro tunnels. In this case the use of lighter weight modular construction even enabled our engineering team to reuse the existing underground station structure and increase the number of floors which added the spectacular top floor sky bar overlooking the Tower of London. Less well known is that modular construction leads to a much lower number of transport movements around the building site, up to 75% less. Supply and removal of building materials would entail major risks at this location because of the enormous amount of pedestrians going in and out the metro station. In addition, a large number of trucks would block the already clogged roads in the city of London.
Our proposal did not only dramatically reduce the number of trucks, it suddenly made it possible to put the majority of the building in place during the night. 70% of the building could be put in place with a small team of workers while the London Underground was closed and the access roads where free. This meant that after the traditional building of the foundation, ground floor and the elevator core all 370 hotel rooms could be put in place in 2 months, whereby the disruption of the inner city traffic could be kept to an absolute minimum.
This combination of factors was decisive for all technical aspects of the construction plan. The point now was that the designers had to succeed in turning it into a modular masterpiece…
A Portland stone façade is mandatory at this location because all of the historic buildings on Trinity Square are built from this material. The larger buildings in the area have a scale and structure in which high columns run over a number of floors and divide the façade.
By cladding the modular part of the building with a self-supporting lightweight façade, lined with Portland Stone, the designers were able to refer in scale and material to the historic environment, while creating a modern building that fitted the citizenM brand. The space between the Portland stone elements is filled with a pattern of metal fins masking the underlying modular grid.
On top of the building two floors have been placed backwards to diminish the perception of its height. This part is made of a light construction of steel and glass. Here you will find a rooftop bar and meeting rooms with spectacular views of the Tower. A large roof terrace surrounds this upper part.
Because it was not allowed to put up large neon logos or advertising shields at this sensitive location, the logos have been embossed in the Portland Stone facade. On the ground floor a large artwork by Julian Opie covers the entire façade of the metro station.
Thanks to this intelligent design, a large modern hotel has been created that doesn’t feel bulky, shows respect for the location and fits in well with its delicate surroundings.
The citizenM Tower of London Hotel is a beautiful example that shows that modular building is more than a full-fledged alternative to conventional ways of construction. Especially in difficult city center locations, the combination of an innovative approach and a good design team can lead to unprecedented new possibilities, which not only improves the quality of buildings, but also reduces urban disruption during construction to a minimum.