While many smart choices were made during the site execution, the most significant project savings – and consequently the most substantial environmental impacts – stemmed from the alternative solutions proposed by Anfra’s design department (Value Engineering). In practice, the structural design and execution methods were refined to reduce material consumption and streamline construction.

A key change was the redesign of the concrete structures, taking production methods into account, which reduced concrete consumption and made execution more straightforward. In addition, the geotechnical designs were revised and the structures were executed using more cost-effective solutions, thereby reducing both earthwork volumes and the site programme.

A significant improvement was also achieved in the reinforcement: compared to the original design, reinforcement was reduced by approximately 30%. When less steel is required, the environmental footprint of both material manufacturing and transport is reduced – while the structures remain fit for purpose.

Another significant environmental improvement achieved through design related to material choices for the earthworks. The originally designed foam glass was replaced with blast furnace slag, which is locally available in Northern Finland. Transport distances were significantly shortened – and at the same time, oil-based XPS insulation was partially replaced, which improves the solution's environmental profile.

In the concrete structures, emissions were also substantially affected by the removal of an unnecessary XA exposure class from the original designs. When the redundant XA class was omitted, the concrete strength class did not need to be raised – the strength class could be lowered. In practice, this means a reduced binder content and a lighter material footprint in subterranean structures – without compromising functionality.

Furthermore, the sequencing of earthworks was developed to suit the challenging soil conditions: settlement was allowed to occur in a controlled manner during winter and spring. When solutions are made right the first time, unnecessary rework and additional masses are avoided at a later stage. We were not able to influence the formulation of the initial solutions, so we proposed a redesign once the project came under our review.

If we are involved from the early stages of a project, a similar need for optimisation naturally does not arise – plans can then be made buildable, material-efficient, and low-emission from the outset.

Further information on plan optimisation: https://anfra.fi/fi/suunnittelu/