The Train Factory



A Heritage Masterpiece

This landmark project is based around a disused train factory building in the centre of the city that was ripe for renovation and conversion and with the possibility of large scale new build opportunities that would help rejuvenate the post-industrial Pasila area of Helsinki.

The Konepaja train factory consists of a complex of historical brick buildings that contained the various processes of train production from car fabrication through to painting. From the air and the adjacent land plot divisions it’s easy to understand how the numerous structures worked in tandem to create the finished trains. As the city had developed the plot had changed from being industrial land into city centre land. The city planning officials had created a wider urban plan for the area, the factory site being a centre piece for the logical expansion and connection of the newly created part of the city to the original centre. The factory plot played a key role city’s plan to create the largest car free zone in Helsinki. The Factory buildings themselves are architecturally interesting, unique within the city and are under the strictest control of the city heritage department who not only want to protect the building fabric but also the key elements that were fundamental to its earlier functions.

The Goal

The brief was to adapt the existing factory structures to commercial and public uses; food halls, market spaces, retail and entertainment venues. The new functions easily fitted spatially within the factories however the change of use from factory to public use would prove very demanding. Armed with a broad teams of experts, third party reviewers and our own heritage consultant we were ready to take on the challenges that would lay ahead.

From Factory to Public Building

The first hurdle was the change in building occupancy. The factory had previously been designed to earlier building codes but for a small number of occupants – the new functions demanded very high occupancies to be successful which drove a number of design decisions in many construction disciplines.

The Challenges

The substantial increase in occupancy raised concerns with whether the existing floor slab would hold the increased weight. This was especially important as the existing timber piled structure had experienced decades of degradation due to changing underground water levels and subsequent local ground subsidence. The increase in occupancy demanded a higher fire rating of the building superstructure which from a heritage perspective was not permissible with any cladding or painting of the original columns and trusses. The necessary fire rating upgrade needed to be achieved with a more substantial sprinkler system that not only kept the space fire free but also cooled the building structure. This led to the next problem; weight. The existing structure was very light (essentially only a large minimally insulated canopy) and could not easily accommodate the installation of a new more substantial sprinkler system needed for fire purposes but also the new heating and cooling system required. The increase in occupancy not only increased the demand for heating and cooling but also humidity control. If left uncontrolled the increased humidity in the building would lead to condensation, rusting and hastened aging of the building which was naturally a concern for the design team as well as the city heritage department.

Balancing Building Physics

With a combined team including three different MEP design consultants a balance was struck that provided a high level MEP installation performance with the lowest possible increase to the weight the roof would have to accommodate. Having developed a proposed it was then tested against a number sequential collapse scenarios as the roof structure was now working considerably harder than it had in the past. The roof thermal performance also had to be addressed as it was again of balance of what could be realistically done to improve its performance within the constraints of the heritage protection and safety concerns. If we increased its thermal performance too much snow would build up on the roof surface in the winter causing additional weight concerns. If we didn’t improve the roof performance then the building could not be sustainably operated. The roof was composed of solid flatter areas of roof and stepper single glazed lanterns. The optimal solution proved to be to upgrade the glazed lantern areas minimizing the footprint of the areas with increased load (the new glazing would be double glazed in contrast to the much lighter existing single glazing). Naturally solar heat gain also needed to be factored into the new design. Even though the new lanterns are built with a much higher performance than the original lanterns we were able to design them in such a way that visually the heritage department couldn’t easily differentiate the old from new lanterns and as such approved them for installation.

Acoustic Hot Spots

One of the toughest challenges was acoustics – whilst functioning as a factory many decades earlier with few neighbours this hadn’t been a problem so the acoustic performance of the original factory could be very weak. Now that the building is city centre and changing to functions that could be very noisy this was a large concern. Earlier temporary events in the factory had already proven the building fabric provided virtually no acoustic dampening at all. Unable to acoustically insulate the entire roof a number of local acoustics ‘hot spots’ were proposed where noisier events could take place. Different acoustic solutions were applied in each location depending on their exact location and the type of noise likely to be generated. The noisiest locations had free standing ‘acoustic boxes’ built around them; this worked well for the event/music spaces and the cinema spaces. The roofs of the boxes became usable area compensating for their additional build cost. Any other hotspots that could not be enclosed were positioned optimally within the building footprint so that the acoustic calculations could easily prove that the noise levels outside the factory walls and in the adjacent apartments were well within building code.

New Build to Improve Urban Porosity

The factory bought by our client was composed of three buildings – two of which were under heritage control. The third building the ‘electrical train building’ (ETB) was built in the 19XX’s and could be demolished and be redeveloped once a change to the city masterplan had been approved. The development of the ETB plot was needed to balance the substantial cost of renovating the period factory buildings as well as providing the future parking for the entire Konepaja factory site (which included buildings our client hadn’t bought). Achieving the city’s plans of creating the largest pedestrian zone in Helsinki would mean the ETB development having to contain all the cars to make this idea a reality.

A number of best use studies were performed that could be used to measure the commercial effectiveness of the combined ETB new build and renovated/converted factory buildings. A number of solutions were studied and regularly workshopped with the city planning department to come to a volumetric and functional solution that met both the client’s investors needs as well as those of the city planners and their wider goals for the area which included many other developments nearby.

Going Forward

A masterplan change process is currently in progress. The final design for the ETB plot included a 300 guestroom conferencing hotel as well as a 20,000sqm headquarters office development with substantial street retail space. The design will develop further as the city masterplan progresses.

The two factory buildings are currently being renovated and converted for their final uses with many spaces already occupied and functioning successfully. Construction on the new components is planned to commence as soon as the city masterplan is updated – with the hotel component already attracting serious operator interest and there are potential tenants lined up for the HQ office space.

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