Two thirds of the building was demolished in the first stage. After that, the building is two stories smaller.
The City of Helsinki will continue the demolition of Jätkäsaari Bunker after Midsummer 2025. Preparations for the worksite will start in early June. The goal is to complete demolition in summer 2026.
Frequently asked questions about demolition
The City is demolishing the Jätkäsaari Bunker (Länsisatamankuja 1).
The first phase of the the demolition was carried out by Lotus Demolition. This final phase of the demolition is carried out by Uudenmaan Infrapalvelut Oy.
The Jätkäsaari Swimming and Sports Centre is to be built on almost the same site as the building being demolished. Centre is highly awaited.
The materials are first sorted at the construction site. All demolition waste will be transported away from the worksite. The waste will be processed and disposed of according to regulations.
In the current demolition phase, it is estimated that 95% of the demolition material will be recycled.
Some of the excavated soil will also be used elsewhere. Based on soil samples, it will either be directly taken to other sites where it can be used or, if necessary, taken to a waste treatment facility. The sampling will be comprehensive.
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 dispersion is effectively prevented by watering the concrete and demolition waste during demolition and the transfer of demolished concrete rubble.
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.
So far, floors 1–6 and the partial attic floor have been demolished. This final phase involves the demolition of the two basement floors and the foundations. All demolition work will end in August 2026.
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.
For now, the demolition work is carried out five days a week, from Monday to Friday. No chiselling work will be carried out in the afternoons from 15.00 to 17.00. The break is timed to coincide with the outdoor play time of the daycare centre next door. During the break, other work will continue on the site.
A notification of noise of the work has been submitted in advance to the City of Helsinki's environmental services. According to the noise permit, work generating strong noise is allowed to be carried out on the site from Monday to Friday between 7 a.m. and 3 p.m. and between 5 p.m. and 8 p.m.
The demolition work is carried out with appropriately equipped excavators and other large machines suitable for the job. The demolition work does not involve blasting. The fleet is type-approved for this work, and its operational condition will be maintained through maintenance and weekly inspections.
Beam structures, shaft walls and load-bearing floors are dismantled partly by drilling and partly with demolition shears. The solid pillars will be demolished by drilling.
In addition to the work carried out with machines, workers will perform tasks such as watering, clearing, cleaning, supervising and other worksite services.
Does the demolition and support work generate noise?
Yes, it does. The work will cause noise disruptions. The worksite operates in line with its existing noise permit.
The noise level is measured regularly at the worksite with standardised sound meters in measuring points near the worksite fence.
Demolition work will always generate noise, but the volume of the noise varies from work phase to work phase. The noisiest phases in the piling process include pile driving, pile drilling and rock anchoring. The noisiest demolition work is the jackhammering of the massive reinforced concrete pillars and foundations. 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. The choice of working hours balances the duration of daily work that’s noisy with the total duration of the demolition.
In basements, the soil wall acts as a natural sound barrier, which can reduce the noise from demolition compared to the previous stages.
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 by wetting.
The construction site aims to prevent mud and silt from ending up on the road network.If dust is carried from the site to the streets in car tyres, the dust would be washed away.
The quantity and composition of particles are measured with particle measuring devices. These devices are placed near the worksite’s fence, at determined measuring points. So far, the measurements have not shown detrimental dust being caused by the worksite operations. Dust and particulate matter also exist in urban areas naturally.
Asbestos and other harmful substance demolition has been completed in a controlled and safe manner, and the scrap has been removed in a safe container.
The harmful substances of the building have been reviewed before. We will take further samples as the demolition work progresses to ensure that there are no substances within the structures that could be detrimental to humans or the environment.
Demolition waste is transported away from Jätkäsaari, which contributes to the number of vehicles in traffic from time to time.
Access to Hietasaarenkuja, which is very narrow, is temporarily blocked.