Every flat and floor in a block of flats that will be completed in January at Arabianranta in Helsinki will be different. The Open Building model, which has been inspired by the architect Esko Kari, offers its residents a world of possibilities: individual choices and solutions at the design stage of a new home.

The ideology based on open construction was originally developed by a Dutch professor, John Habraken. In Finland the firm of architects ARK Oy Kahri & Co has developed the practice in several projects from the beginning of the 1990s in partnership with managing director Esko Enkovaara from the construction software company Tietotalo Tocoman Oy.

The decisive step for the concept was taken when Kahri and Enkovaara suggested to the building contractor SATO Rakennuttaja Oy that it take part in a technology competition in 2000. SATO Rakennuttaja won and in 2001 the company PlusKoti Oy was set up to produce Open Building services.

"The integrated service of an architect and construction software company and the information modelling of designs now make it possible to control numerous options for both customer service and construction," Kahri says.

"The concept has been presented at many international congresses. In Sweden and Denmark, for example, the model has aroused great interest. An EU project involving 5 or 6 countries is also being studied. Gratitude and international appreciation have also come from the father of the idea,too," says a happy Kahri.

Shell and core separate

Open Building allows for individual dwellings planned by the future residents at a reasonable price. The building process involves a separate framework and interior stage i.e. the "shell and core", which have been arranged to be as independent of each other as possible.

The process is based on making alternative structures by means of a framework in which the flats do not need to be the same on top of each other and the buildings can also be very individual to look at. The process includes not only a wide choice of flats but also a large number of options in fixtures and materials. The whole process operates via an Internet service.

"When they reserve a flat in the new building, future residents are given a password with which they are able to explore a world of possibilities. On offer are a large number of different basic solutions, sloping walls, alternatives for windows and balconies, materials and additional fixtures and fittings. When testing their choices on the Internet, the future residents see immediately what they are paying for," Kahri explains.

The starting point for the polymorphous construction is the framework that makes the different flats possible. The best framework has proved to be a steel-based structure developed by Finnmap Consulting. The advantage of it is the quick construction using big elements in which the outer walls are load-bearing and the partition walls are steel-framed with excellent sound-insulation.

Operating model spreading

Open Building is based on the main operating principles of an advanced, order-driven industry, a feature that brings challenges to the entire construction operating chain. The process requires customer choices to be implemented with special control over the areas of contract technique, information technology and logistics.

"The application of advanced information technology in the implementation process also requires maturity from the building company's own information systems and staff in exploiting information produced by 3D modelling," emphasizes Esko Eskovaara.

With the model it is possible to achieve a considerable improvement in cost-effectiveness and economy as the quality of the design and the value experienced by the customer increase. In addition to the building that will be ready in January, two new projects are already under way. In the future attempts will be made to start 3 to 4 new PlusKoti buildings based on the Open Building concept.
"PlusKoti represents at this moment perhaps the most advanced operating model in the construction industry, and it is one that will probably spread in the industry," Enkovaara believes.

>> www.pluskoti.com
>> www.tocoman.fi

There are several variations of the two-roomed flat in the picture. Essential are adaptability and the large windows and lighting.