In accordance with the building permit issued, two thirds of the building will be demolished in the first stage. The remaining parts are to be torn down when the plan for the new swimming and sports centre is ready. The schedule of the new project is currently undecided.
After this phase, the building will be two stories smaller. Much of the demolition is also carried out inside.
Working hours
Demolition work is carried out in early autumn 2024 from Monday to Thursday. Daily working hours on the construction site are limited so that significantly noisy work is done from 9 am to 4 pm, work that causes normal construction site noise from 7 am to 6 pm, and quiet work until 8 pm.
There is a break in the use of heavy machinery on the daycare centre side and the demolition of facades from 4 pm to 5:30 pm.
The working hours are shorter than what the environmental authority's noise permit allows.
Demolition work is carried out piece by piece in safety
The demolition work is carried out on the outer shell using a demolition machine with a long boom. The equipment is type approved for this work and its functions are maintained with regular maintenance and weekly inspections. The machine operator is assisted by a so-called spotter, who monitors the demolition process and instructs the machine operator with a walkie-talkie. Blasting work is not carried out in this project.
The beam structures, shaft walls, pillars and load-bearing floor inside the outer shell are dismantled with spikes and shears.
The construction site is fenced with a fixed fence two meters tall, making the area outside safe to move around. Access to Hietasaarenkuja, which is very narrow, is temporarily blocked at the demolition site. On the Hampurinkuja side, the street area is partly reserved for the construction site.
The asbestos elements inside the building have already been torn down in a controlled and safe manner, and the scrap has been removed in a safe container. A prior survey of the building's contaminants was carried out. We take additional samples as the demolition work proceeds to ensure that there is no material inside the structures that can cause harm to people or the environment.
Efforts are made to reduce hazards at the construction site
Demolition and construction always creates some amounts of noise and dust. Dust is prevented at the construction site as effectively as possible through the choice of working methods and the use of snow guns, high-pressure hosing of the demolition machine and, if necessary, with regular water hoses.
In August 2024, the construction site introduced a separately supported protective mat to prevent the spread of dust, noise and scrap. Initially, the mat is used on the daycare centre side of the construction site.
As of mid-August 2024, the amount and composition of the dust will be monitored with two particle size sensors. The sensors are installed outdoors near the daycare centre and school fences.
Demolition work will always generate noise, but the volume of the noise varies from work phase to work phase. The noisiest stage of work is spiking. Moving and loading of the scrap will also generate some noise.
There is no use for demolition scrap in the construction of the area, which is why it is transported elsewhere. This creates construction traffic.
The developer of the demolition project is the City of Helsinki's Urban Environment Division. The primary contractor for the demolition contract is Stara and the first phase of the demolition is subcontracted to Lotus Demolition Oy.
We will continue to communicate with the adjacent school and daycare centre as the work proceeds.
Frequently asked questions about demolition
The City is demolishing the Jätkäsaari Bunker (Länsisatamankuja 1) in phases. Lotus Demolition will continue the demolition of the first phase of the Bunker, which started in the spring and is expected to be completed in early 2025.
On the site of the demolished building, we will be constructing the Jätkäsaari swimming and sports centre, which is highly awaited.
According to the building permit, approximately two-thirds of the Jätkäsaari Bunker, which has six stories, an attic and a basement, will be demolished at this phase. After this phase, the building will be two stories smaller. To a significant extent, demolition is also carried inside the building.
In the second phase, the rest of the building is demolished and the ground is prepared for the needs of new construction
Demolition of a building the size of the Bunker generates a large amount of demolition waste. The materials are first sorted at the construction site, after which they are transported away to be utilised for various purposes by the demolition contractor.
There is no use for demolition waste in Jätkäsaari. Gravel made from concrete scrap can be used, for example, in the foundation for parking areas and outdoor routes, or in railway yards
Yards can be used normally. The construction site area is cordoned off with a two-metre tall plywood fence for its entire circumference to prevent outsiders from entering the demolition site. It is safe to stop and walk on outside the plywood fence.
Unfortunately, the site will generate noise. Dust buildup is effectively managed by irrigating the concrete dust that is generated by the demolition work.
A prior survey of the building's contaminants was carried out. We take additional samples as the demolition work proceeds to ensure that there is no material inside the structures that can cause harm to people or the environment. Asbestos elements were torn down in a controlled and safe manner in the spring of 2024.
The bunker will be demolished in two phases. The first phase began in spring 2024 and will be completed in spring 2025, approximately in February.
The schedule for completing the demolition work depends on the schedule of the replacing construction. This schedule is undecided as of now.
Demolition takes time because the target is very large, with heavy structures. The safety of the nearby operators, such as the daycare centre and school, must also be taken into account in the choice of working methods and in the planning of working hours
Demolition is carried out from Monday to Thursday for the time being. Daily working hours on the construction site are limited so that significantly noisy work is done from 9 am to 4 pm, work that causes normal construction site noise from 7 am to 6 pm, and quiet work until 8 pm.
On the daycare centre side of the site, large machines are not used to carry out heavy demolition at all, and none of the facade shell elements are demolished between 4 pm and 5:30 pm.
A notification of noise of the work has been submitted in advance to the City of Helsinki's environmental services. The working hours of the Bunker's demolition site are shorter than what the noise permit issued in early autumn 2024 allows.
The demolition work is carried out on the outer shell using a demolition machine with a long boom. The equipment is type approved for this work and its functions are maintained with regular maintenance and weekly inspections. The machine operator is assisted by a so-called spotter, who monitors the demolition process and instructs the machine operator with a walkie-talkie. Blasting work is not carried out in this project.
The beam structures, shaft walls, pillars and load-bearing floor inside the outer shell are dismantled with spikes and shears.
Does demolition create noise or dust?
Yes, it does. However, we are doing our utmost to reduce the inconvenience. We follow the instructions and regulations issued by the city's environmental authority, the purpose of which is to regulate construction sites in a way that does not cause an unreasonable instructions to the neighbours.
The sounds of demolition and loading carry into the surrounding environment in different ways, depending on where the work is done and what type of building part is being demolished.
Demolition work will always generate noise, but the volume of the noise varies from work phase to work phase. The noisiest stage of work is spiking. Moving and loading of the scrap will also generate some noise.
How do you control the noise levels?
Noise management is mainly done through the choice of working methods and limiting working hours. Blasting work is not carried out on this site. The choice of working hours balances the duration of daily work that’s noisy with the total duration of the demolition.
On the side of the school and daycare centre, the construction site is protected with a solid suspended wall of mats, which also has a minor sound-absorbing effect. The building itself is a sound barrier, so sounds are emitted the most while building parts in the vicinity of the listener are being demolished.
How is dust controlled and monitored?
Anti-dust measures at the construction site are as efficient as possible. Dust is prevented through the choice of working methods and the use of snow guns, high-pressure hosing of the demolition machine and, if necessary, with regular water hoses.
A suspended protective mat is also used to prevent the spread of dust, noise and scrap.
Water cannon spraying can be mistaken as concrete dust, but is instead a very fine mist.
Tyres of the vehicles leaving the construction site are washed to prevent dust from being introduced to the street network. If dust were to get on the ground, it is washed off.
The asbestos elements inside the building have already been torn down in a controlled and safe manner, and the scrap has been removed in a safe container. A prior survey of the building's contaminants was carried out. We take additional samples as the demolition work proceeds to ensure that there is no material inside the structures that can cause harm to people or the environment.
The amount and composition of the dust is be monitored with two particle size sensors. The sensors are installed near the daycare centre and school fences. Harmful dust has not been detected from the construction site in random tests. Dust and particle depositions also occur naturally in urban areas.
A prior survey of the building's contaminants was carried out. We take additional samples as the demolition work proceeds to ensure that there is no material inside the structures that can cause harm to people or the environment
Demolition waste is transported away from Jätkäsaari, which naturally contributes to the number of vehicles in traffic from time to time.
Access to Hietasaarenkuja, which is very narrow, is temporarily blocked at the demolition site