Kulma21 is the architect’s dream

Architect Hanna Koskela is happy to be involved in NCC’s development project whereby the iconic KY Building will be transformed into the new Kulma21. ”It feels great, being able to revive an old building and restore its original splendour,” Koskela says. The KY Building will be renovated into an office building to support modern working culture which will open to the tenants in 2023.

Like many a Helsinki resident, Koskela has keen memories of the KY Building dating back to the days of her student life. The fact that the project stopped briefly by her workdesk a few years earlier makes it even more interesting.

”To my regret things did not work out then, so I’m delighted to be able to return to this interesting project now,” Architect Koskela of architectural firm Tengbom Oy smiles.

The multi-layered history of the KY Building is inspiring to Koskela who loves working with renovation projects. The building which was completed in 1941 was originally designed by architects Toivo Paatela and Seppo Hytönen as a student dormitory, although the use as a hotel was considered too.

”Over the years, the house has been used for living and office while in the 1970s its use was determined by the detailed plan as a block area of commercial spaces. The occupancy rates of the property have remained low for several years now, which is why I’m finding it particularly fascinating to think of a new life for the building,” Koskela reckons.

Kulma 21_Tengbom_Satu Tervo, Hanna Koskela, Minna Hulkkonen

Members of the Kulma12 Team at Tengbom Architects, from left to right: Satu Tervo, Hanna Koskela and Minna Hulkkonen. Katja Krooka is missing from the picture.

A building of great potential

Despite the fact that the project entails renovation of the iconic KY Building, the architect does not feel burdened by restrictions. The currently valid planning provisions do not protect the building, but it is included in the listing of built cultural environments of considerable national value maintained by the National Board of Antiquities of Finland.

”We have established jointly with the planner, the building control and the City Museum that, despite the cancellation of the plan alteration process, the protection targets thereby determined be considered, so we will relate to the building as it were protected all the same,” Koskela states.

”The site has a lot of potential. The building’s framing was originally designed for residential use, but owing to the column-and-beam structure it is virtually suited to any use, considering the constraints of the frame depth and window spacing. Of course, it will be challenging to build ’new’ over ’old’ from the building services’ point of view.”

On floors 1-6, only measures of restorative nature are allowed. Most of the changes apply to the seventh floor, which is practically re-built respecting the original idea and considering existing structures.

Something new, something old

The target of the renovation project is to raise the building to the value it originally had, and to accentuate its particular features which have faded due to the changes made over the years. This means, for example, that the façade is re-built with elements which once were there.

”Plastering shall remain as the façade material, only its colour is lightened to accentuate the building’s original appearance in the streetscape. We are not sure about the exact colour of the original façade plastering, but the matter could be solved still in the demolition process.”

”The clinker façade tiling will be renewed using a natural cladding stone of grey colour that is similar to the original cladding. All windows are renewed too, except for the original wooden windows of the second floor which are repaired according to the protection targets,” Koskela describes.


Illustration: Oladesign

Demolition works could reveal hidden treasures

Koskela thinks it takes something of a detective to renovate an old building. There are many things to be finally solved yet during the demolition phase. The existing drawings will be reviewed and the structures examined carefully in situ by knocking on them. Old photographs and the building history report bring additional clarity to the works.

”There is still a lot to be clarified, but we will proceed as the demolition progresses, and react accordingly. The structures may present surprises that could have an effect on the renovation works. The surprises to unfold while working on an old building like this makes it all more interesting,” Hanna says.

”In this project we will not settle for concealing old under new, but the purpose is to explore, open, clean the structures and assess the original features that bear significance from the building history viewpoint. The building has lived a versatile life for several decades, but I hope to find even more treasures during the demolition.”

First renovation to be rated Excellent in Finland

The old KY Building will transform into Kulma21 in about two years. According to Koskela, the building is unique in many ways, both by the location and the history spanning eight decades. It is also a major attraction among the city dwellers.

Kulma21 is unique even by the high targets set for its environmental rating: it will be the first property in Finland to be built to level Excellent according to the very latest BREEAM criteria for renovation projects. Koskela says the BREEAM requirements guarantee that everything will be implemented at the highest possible level.

”Our joint target with NCC is to co-ordinate the entire project so that the building history values are understood and the dialogue maintained with the authorities. Renovation projects require smooth co-operation between the different parties,” Koskela summarises.


  • NCC’s development project which entails transforming of the existing Business Student Union, or the KY Building, into versatile office space to nudge the working culture of a better future. The refurbishment works are performed with due respect to tradition.
  • The building has a unique history as a centre for living, student life, retail and entertainment.
  • The first project to be implemented in Finland to level Excellent according to the latest BREEAM criteria for renovation works.
  • Kulma21 is located in central Helsinki, at the corner of Pohjoinen Rautatiekatu and Fredrikinkatu streets, next to abundant services and traffic connections.
  • Kulma21 offers 7600 sq. m. of leasable office space.
  • Read and find out more about vacant office spaces on kulma21.fi

Share article:

Related news

Read the latest news about Kulma21.

Kulma21 – exquisite modern office space in Helsinki city centre

NCC is a recognised developer of new properties, but also known for its renovation projects which permit recovering old buildings to a new splendour. ”It’s great to be able to continue...

Renovation projects that inspire and engage

NCC is a recognised developer of new properties, but also known for its renovation projects which permit recovering old buildings to a new splendour. ”It’s great to be able to continue...