Hollow-core slabs are an ideal flooring solution to even the most complex buildings


Hollow-core slabs are an ideal flooring solution to even the most complex buildings

Libraries are usually thought as homes for books, music and other things that can be borrowed, but they can be much more than that. In Finland, Helsinki Central Library Oodi is built as a modern library, which will cater to the needs of the public.

This digitally intelligent library is being built to the Töölönlahti area in Helsinki, where it complements the already existing culture cluster. An architectural competition was organized, where the winning design for the library was chosen on June 14th, 2013. ALA Architects Ltd won the competition with their design. ‘’It is quite uncommon today that in the western world and in a stable country, something as novel as this is being built to such a prominent location. There are of course some examples, but they are so few that they can almost be counted on one hand.’’ comments Antti Nousjoki, architect and partner of ALA Architects.

The dynamics between the location and the space usage created the framework for the building design. The guiding idea was to create three floors allocated for different uses, which would all be connected to one another and flow seamlessly together. The ground-floor front facades are made out of glass in order to connect the inner public spaces to the Citizens’ Square outside. From the third floor people can peacefully admire the unparalleled panoramic view of Kiasma Museum of Contemporary Art, Parliament House, Helsinki Music Centre and Finlandia Hall congress house and event venue. The rest of the facades are made out of wood, which curve around the exterior walls. These soft shapes are present everywhere in the library.

"The Central Library will be one of the freest buildings in Helsinki, or even the Nordic Countries, where the visitors can do many things and take initiative in what they want to do. I believe that people will be positively surprised with Oodi. We are not building a monument, but a part of the well-functioning city." says Nousjoki.

A completely unique entity requires a lot – planning in advance, accurate control and tight schedule management – from the contractor too. YIT Rakennus Oy is responsible for the construction work. ‘’In a unique project, each stage of work is unique and takes time. We must demand that all participants keep on schedule, because the progress of work is sometimes dependable on the smallest of things and any delay is difficult to catch up. There is no systematization in Oodi. We cannot act as at a car factory: put parts on the conveyor belt and assemble’’ explains Mansoor Ardam, foreman at YIT.

Because of the load-bearing capabilities and fast erection, hollow-core slabs were chosen as the most suitable solution for the flooring. Parma, a part of the Consolis Group, Elematic customer and the largest precast product manufacturer in Finland, delivered around 5,800 m² of hollow-core slabs to the construction site.

Helsinki Central Library Oodi in detail:

  • Location: Helsinki, Finland
  • Year of construction: to be opened in December 2018
  • Gross area: 17,250 m²
    • Library functions, group working spaces, recording studios, maker space, movie theatre, multipurpose areas, a café, a restaurant, etc.
  • Developer: The City of Helsinki
  • Constructor: YIT Rakennus Oy
  • Architect: ALA Architects Ltd
  • Structural designer: Ramboll Finland Oy
  • Concrete element supplier: Parma Oy
  • Amount of concrete elements: approx. 5,800 m² of hollow-core slabs
  • Cost estimate: 98 million Euro


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