Thorough preparation pays dividends

Gerelateerde Projecten

Conservatorium hotel

The work carried out by Oskomera on the five-star Conservatorium Hotel in Amsterdam has been completed. The project was executed without any significant problems or delays. This was primarily thanks to carefully thought-out preparation and a precisely planned routing for just-in-time delivery of the necessary parts. Several unique, bright steel staircases were also incorporated into the interior during additional work.

Oskomera has made a significant contribution to both restoration and new building work at the Conservatorium Hotel in Amsterdam's Van Baerlestraat. This includes a glass roof with a surface area spanning over 45 x 18 metres, a glass curtain wall almost 20 metres high showcasing balconies, full-glass facades incorporating curved glass around the multi-level conference area, a unique stairwell including four, straight-flight staircases, a zigzag staircase between the conference area and original building, as well as various steel, mirror-clad stairs, two of which are zigzag shaped in the bar and store areas.

Precise measurement

Although the various structures are fairly sophisticated and some closely connected, the construction process ran faultlessly. "Thanks to the preparation the project team put into the job," says Site Manager Christian Smits. "The measurement in particular determines projects like this, where you need to adjoin a structure to the original building. In order to determine the precise level of the original building as opposed to the new parts to be manufactured, in other words the precise measurement, a full, three-dimensional digital survey was carried out on the existing building. The design, which was also created in 3D, was then aligned and on that basis the various parts of the roof, facades and balconies were manufactured. As a result, everything was a perfect match. Investing time in thorough preparation creates time savings during execution".

Auxiliary structures

"Before work commenced, a good look was also taken at where we might come under pressure with regard to stability during construction", Smits continues. "The balconies, which hang on the roof trusses, add stability to the new curtain wall. So you can only hang them up when the roof trusses have been fitted, but these need to rest on something. An auxiliary structure was therefore placed behind the high curtain wall and the balconies were temporarily laid on this. After the balconies and curtain wall had been constructed and coupled to the trusses, the auxiliary structure was dismantled."
Another example of Oskomera's expertise is the auxiliary structure with a pulley block and crab winch supporting the conference area and the short balconies in order to be able to position the incredibly heavy zigzag stairs and straight-flight staircases. Smits: "Parts needed to be supplied just-in-time, as there was no storage space on the building site. During the period leading up to this, the project team had detailed discussions about the order of assembly, which parts of certain structures would be needed and when. This was translated into a production and supply schedule. This also took some time, but the schedule proved its usefulness. We never once came to a halt because the wrong construction parts were delivered to Amsterdam. They may have arrived later on occasion, but that was usually due to busy traffic".

Additional works

Our clients were evidently happy, as the project was followed by a number of subsequent projects. These include a further ten steel staircases, which were fitted inside the hotel. "The staircase in the bar is particularly special," explains Smits. "It's a miniature version of the zigzag staircase in the atrium. The only difference is that the closed sides are clad with mirrors to make it less striking. The staircase is a total height of 3.60 metres and weighs 3500 kilos and was introduced through the side of the building from the street. It was necessary to dismantle an existing wooden window frame to achieve this. With only millimetres to spare, an overhead crane was used to move and turn the staircase into position. Again, this job was measured in advance to make sure it was possible and a detailed examination was made to see how the staircase needed to be moved, tilted and turned. The balance point of the stairs had already been determined in the factory in Deurne to make sure it could be picked up, lifted and adjusted correctly". Two more steel zigzag staircases, weighing 1800 and 1200 kilos respectively, were placed in the 'shopping centre' on the street side of the building. These staircases, also introduced through existing window frames, are constructed from two parts, which makes assembly slightly less complicated.

Extremely satisfied

The work in Amsterdam is complete and everyone is satisfied: the client because a beautifully crafted range of bespoke staircases have been delivered; and Oskomera because everything was executed according to the way it was envisaged by the project team. So thorough preparation does pay dividends.