Omistusasuntoja Helsingin Arabianrantaan
kilpailuvoitto 2001, toteutus -2005

The PlusHome - Arabianranta, Helsinki
by ArkOpen Ltd, Architects Esko Kahri, Petri Viita, Juhani Väisänen & PlusHome Ltd


The PlusHome - Arabianranta, Helsinki

The project is based on the winning entry to a technology competition in Helsinki in 2001, arranged by the City of Helsinki and TEKES, a public institute for supporting development of technology. Through the competition the City was searching for new urban solutions in accordance with the Open Building principles. Arabianranta is a new housing area to be built on the sea shore about 5km from the centre of Helsinki. The building was finished in the beginning of 2005.


The Buildings

The 6-storey buildings houses 77 residential apartments in sizes between 39m2 and 125m2. Also on the street level there is one 84m2 space to be used as a shop and seven workshop spaces (31-46m2) for artisans etc., four of which are connected to second floor apartments by inner staircases. The residents have the use of a laundry and drying room, two meeting rooms and two roof saunas with terraces overlooking the sea. In the cellar are individual and common storage rooms and a fall-out shelter.

The construction frame for the building contains a few features that differ from the traditional way of building in Finland:

- The load-bearing walls are the outer, longitudinal walls instead of the cross-walls between the apartments. This is of course for providing a flexible space for varying lay-outs on different floors.

- The load-bearing structure inside the walls is steel columns at max. 3m intervals. Connected to the columns are Z-formed steel beams, which bear the concrete slabs. The steel constructions are insulated against fire and cold.

- Most of slabs are part concrete hollow-slabs of about 10m span. On the zones of sanitary spaces two-layer slab is used, which allows flexible plumbing. On the underside the beams are connected to a concrete slab to form a prefabricated element. After plumbing installations the top part covered with a profiled sheet-metal-concrete slab.

The steel-framework makes it possible to prefabricate the walls in large elements. This makes construction on site very quick. Also the construction work is dry with very little in-situ concrete casting, which is favourable in our climate.

The Facade design is free allowed by steel-structured outer-wall elements with almost unrestricted fenestration and outer facing of the facades built on site. In this building the exterior is made of red brick or clad with thermal plastering, some parts of profiled metal plate. The balcony slabs are made of concrete and supported by concrete filled steel tubes. The rails and dividing walls are aluminium-glass construction, balcony glazing is optional. On the outside of the balconies there are sliding aluminium grids for sun protection and view blocking. The glass rails can be fitted with roller blinds for providing more privacy. The balcony sliding grids and the blinds give an ever changing appearance to the facades, reflecting the individual variety of the residents.


The In-fill and Customer choices

The dividing walls between the apartments are light construction consisting of double frame – insulation – double plasterboards. The bathroom walls are light weight concrete. The ventilation system is individually adjustable, with both mechanical in-take and out-take of air including the reclaiming of heat. The electric installations are made using on open distribution profile on the upper part of the partition walls, which provides flexibility and enables the adding of service systems such as networks and security systems for the elderly. Thanks to the flexible in-fill parts, the pilot project had very wide choices.

Residents could choose between alternative floor plans, which were presented in the pre-marketing stage via internet: A wide selection of floor plans was offered, both different apartment sizes and variations within the same size. This stage was open till about 6 months after the construction started. The building was filled with floor plans according customers’ choices and all the floors became indivudual. After this stage the residents had another 3 months for the selection of surface materials, fixtures and accessories with fixed prices through the internet pages. The buyers could see the change in the total price of their apartment directly after making their choices, and could also go back and revise before finally accepting the order.

The data processing feature of the PlusHome-concept was developed and carried out by IT- and data consultant company ToCoMan Group. Most of the later projects will have limitations of more traditional building structures, but the main OB-qualities and all the internet services will be kept and continuously improved.


The Developer & Concept

The SATO-Corporation is one of the largest housing companies in Finland. SATO has outlined its future strategy towards open building by using the PlusHome-concept. The concept includes three levels with advanced internet-services.

- BASIC with alternative equipment, materials + some floor plan variations

- WIDE including previous + alternative floor plans within the same size

- OPEN including previous + also changing the size of the apartments

SATO corporation has made a decision to widen the concept in the next few years to all their production of owned apartments. SATO has the PlusHome Sole Right in Finland except the basic-level, which is open to be used by other builders as well. After the pilot project two more blocks of flats have been finished and five more projects are in the design stage, where three other architect offices are also involved.