Compact cities and efficient land use with tower buildings
YIT Corporation News, June 27, 2017 at 10:00 a.m.
What are suitable or unsuitable locations for towers? It is a matter of opinion, but if any location is suitable, it is the new Pasila. This is the view of Juha Kostiainen, Senior Vice President of Sustainable Urban Development and Harri Isoviita, Senior Vice President of Residential Construction at YIT.
What makes Pasila a good place for high-rise buildings? Juha Kostiainen bases his opinion on the fact that Pasila has been surrounded by wasteland. The eastern side is home to concrete buildings from the 1970s, to which higher buildings would create a nice contrast.
“The railway yard will require substantial construction efforts, it won’t be possible to change the look with just small measures.” Towers would change the entire nature of Pasila,” says Kostiainen.
He notes that three large building complexes are currently being built in Tripla in the centre of Pasila.
“It would be downright embarrassing to build three-storey buildings next to them. Tripla’s urban landscape requires expressivity.”
According to Harri Isoviita, the pace of urbanisation is increasing. High-rise buildings have been noted as a good solution around the world, why not in Finland?
A tower area is currently being planned for central Pasila. Decisions on the planning and implementation will be made in autumn 2018. In the reference plan, the highest tower has 40 storeys.
Kostiainen notes that smart cities build different urban environments. The Empire-style centre should be preserved as a historical part of Helsinki, while new one-family houses are suitable for areas located further away from the centre and closer to nature.
In some parts of the city, urban, high-rise buildings can be very attractive. Manhattan is a good example of this.
“When used in moderation, high-rise buildings give the city character, a profile and make it identifiable.”
In a smart city, people who value different things can find different environments that please them. Diversity and different layers make areas more interesting.
The indisputable plus side of high-rise buildings is its area density, which is especially needed when plots are scarce.
“Finland’s is sparsely inhabited, which is a problem. Services are far away, and as a result, you need to use a car to get form point A to point B and, at the same time, people wonder why services are not available closer by.”
Density is an urban feature. Kostiainen states that the general plan of Helsinki takes this account quite well, while also addressing future possibilities.
“The direction of construction should not be further away but rather inwards, complementing the city. Not everything has to be low, and offering people different alternatives is always a good idea.”
Another positive aspect of high-rise buildings is their energy-efficiency, as infrastructure benefits from having a large number of people in a small area. Thanks to high-rise buildings, it is also possible to improve the efficiency of land use in the rail traffic station areas. In addition, towers become landmarks that companies can utilise when building their image.
Building towers has its own rules
How is high-rise building different when compared to more conventional construction projects?
Isoviita immediately comes up with a long list of differences. He has practical experience on the subject, for example from the Cirrus building in Vuosaari, Helsinki.
“High-rise buildings require solid expertise from the designers. There are different official requirement classes, and for high-rise building, the highest class applies.”
The City of Helsinki has prepared guidelines for high-rise building, applicable to buildings with more than 16 storeys.
As an example, Isoviita mentions that for the structural design of high-rise buildings, an inspection conducted by an external party is required. In other words, the design work of an agency is inspected by another agency to ensure that there are no human or other errors in the plans.
For instance, the exit routes of high buildings must be carefully considered. There are specific guidelines for lifts, and designers must be aware of them. There are also several instructions concerning fire safety, including sprinklers and smoke venting.
“Sprinklers are the most effective way to stop fire from spreading. Apparently there were no sprinklers in the tower building in London,” says Isoviita in reference to the recent disaster.
In addition, the tower buildings will be equipped with two smoke-protected exits. Furthermore, there are fire collars in the bushings between floors. The material stops the spread of fire from one floor to another.
The designers must also be familiar with increasing water pressure: people will want to shower even on the top floor. In addition, the construction work itself is subject to guidelines that aim at preventing risks.
The impact that the towers have on the wind and shade conditions must be taken into account. For example, the Finnish Meteorological Institute participated in the development of the Cirrus building by conducting wind analyses.
The special requirements of high-rise building are costly, but how much they exceed the costs of an ordinary building always depends on the project. Isoviita explains that it is easier to design and build a straight, vertical building than one that narrows and widens like an hourglass.
“However, the height of towers is already an international competition. It is becoming increasingly common for towers to be built as hybrid projects, with a single building comprising business premises, offices, a hotel and apartments. This means the surrounding area is also lively during evenings and weekends and infrastructure can be utilised more efficiently,” Isoviita explains.
Buildings that clearly deviate from the surrounding building stock and are visible from far away. They affect the silhouette of a city.
The Helsinki High Rise competition will be organised to find a high-quality plan for the tower area planned for Pasila.
According to the reference plan, the tower buildings in Pasila must have at least 15 storeys.
Harri Isoviita, Senior Vice President, Residential Construction, YIT Construction Ltd, tel. +358 40 553 3833, firstname.lastname@example.org
Juha Kostiainen, Senior Vice President, YIT Corporation, tel. +358 400 721 475, email@example.com
Hanna Malmivaara, Vice President, Communications, YIT Corporation, tel. +358 40 561 6568, firstname.lastname@example.org
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