Starting point

City of Lahti organized an invitational architectural competition for a pedestrian and cycling bridge crossing Loviisanpässi Park.

The aim was to design a bridge of high architectural quality that is structurally and technically efficient, feasible, and sensitive to the historical value of the former railway cutting and the park’s green environment. Particular emphasis was placed on preserving the area’s mature tree canopy as part of a wider natural system.

Location

Solution

The organic form of the bridge, named ”Varjo” (Shade), emerges directly from its context. The alignment responds to the park’s dense, character‑defining tree cover: mature trees are carefully avoided, and smaller vegetation is preserved wherever possible. Each tree that must be removed is replaced with three new plantings, allowing the park’s lushness to increase over time. The geometry of the bridge also responds to pedestrian flows from the Vesijärvenkatu crossing and adjacent bus stop.

Its exterior is clad in recycled wood treated using the Shou Sugi Ban charring method. The darkened surface recalls the site’s railway history, while also protecting the timber and giving it a calm, cohesive appearance. Varying board widths and thicknesses lend the vertical cladding a subtle liveliness.

For users crossing the bridge, the experience is defined by warmth and tactility. The deck is finished in natural wood and enclosed by solid timber parapets. Steel lattice guardrails act simultaneously as the primary load‑bearing structure and as a defining visual element of the bridge. An orthotropic steel deck ensures a lightweight yet rigid structure, reducing vibrations typical of pedestrian and cycling bridges.

Bat roosts are integrated between the underside elements, using the bridge structure itself as habitat. Positioned on the sun‑exposed southern side, the roosts benefit from warmth absorbed by the darker surfaces. The integration of these micro‑habitats embeds biodiversity directly into the architectural concept and supports urban ecological diversity.

From a traffic safety perspective, the alignment and cross‑section of the bridge respond carefully to the adjacent intersection. The deck widens toward Vesijärvenkatu to prevent parapets from obstructing sightlines. Clear visibility is maintained through selective pruning of lower branches and the introduction of carefully placed trees passing through the deck, subtly encouraging slower approach speeds. On the health centre side, height differences in the terrain are resolved with gently sloped ramps to ensure a comfortable and safe longitudinal slope.

Small‑scale artworks are embedded along the inner faces of the bridge, offering moments of discovery—particularly for children. The experiential approach continues in the lighting strategy: both the bridge and the park path are illuminated with intelligent, movement‑responsive lighting that brightens when users are present and fades when the space is unoccupied. Reducing light pollution enhances both human comfort and the well‑being of other species.

Varjo brings together movement, landscape, and architecture into a cohesive whole. It is both a piece of infrastructure and a place — an intervention that respects the existing environment, adds a new spatial layer, and creates a connection that is simultaneously practical, atmospheric, and ecological.