Ulf Mejergren Architects (UMA) designed the Spruce Bark Hut in Grödinge, Sweden, to explore spruce bark as a bio-based building material. The team collected the bark from forests affected by the spruce bark beetle, which has damaged large areas of spruce woodland across Europe. As the trees weaken, the bark loosens and falls away, creating a readily available local material.

In this project, the architects treat bark—usually seen as waste—as a usable resource. As a result, the project aligns with approaches that prioritise locally sourced and underused materials.

Construction Approach And Structural Strategy

The design draws on natural processes. On the one hand, the bark beetle creates the material supply. On the other hand, ants inspire the construction method through their incremental way of building. Accordingly, the architects built the hut around a living spruce tree, which acts as a central structural element. They added a secondary framework of timber studs and masonite boards to support the bark layers. Then, they attached the bark manually using simple tools. This low-tech process allows for flexibility and responds directly to the irregular shape of the material.

Material Properties Of Spruce Bark

Spruce bark has a thin and flexible structure. Therefore, it behaves more like a sheet than a solid panel. Designers can fold and layer it instead of fixing it as rigid cladding.

As the layers overlap, they form a lightweight and permeable outer skin. Consequently, the envelope provides limited enclosure while maintaining a strong connection to the surrounding environment. This behaviour suggests potential for temporary structures and experimental façade systems.

Spatial Experience And Environmental Integration

The hut has a tent-like shape and encloses a compact interior space, which visitors enter through a narrow opening. Inside, it functions as a simple shelter for short stays. At the same time, the material and colour help the structure blend into the forest, while its form remains clearly visible.

By building around a living tree, the project creates a direct relationship between the structure and its environment, both physically and conceptually.

Material Experimentation Within A Circular Context

The Spruce Bark Hut shows how designers can use forest by-products in construction. In particular, the use of bark as a cladding material reflects a growing interest in bio-based materials and circular design strategies.

Although the project remains experimental, it contributes to ongoing discussions about alternative material applications in architecture and design.

Source & photos: Ulf Mejergren Architects