Mellor is a small village not far from the Stockport/Manchester conurbation, yet on the edge of open country and the Peak District National Park.

Its primary school, looking out over woods and fields, has a Forest School ethos, which holds that learning through the the outdoor environment is key to helping children build resilience, resourcefulness and an ability to work together. It is an ethos closely reflected in its new extension, designed by Sarah Wigglesworth Architects.

Like a ‘tree house in the woods’, the extension is a cluster of timber-clad pitched roof forms set on a deck which extends into the landscape. It offers a series of exciting and stimulating spaces, both indoors and out, that supports the forest school curriculum.

The design was the result of close liaison between client, project partners and the local community. Timber is the dominant material used in the extension, chosen for its qualities of low energy, robustness and sustainability; it also reflects the school’s Forest School philosophy and allows the building to sit comfortably within its green belt setting.

Walls are clad with cedar shingles and vertical cedar boards, while tree-like glulam frames support the roofs internally and canopies externally, making visual connections between internal and external spaces.

The school, set on the outskirts of the village, is a 1990s single storey building designed to an open plan layout with its main entrance and playground on the south side. In order to provide uninterrupted access to the main entrance throughout the build, the extension is located on the north side of the school, where the ground slopes steeply downwards into a woodland landscape. This presented a challenge, but also an opportunity to transform the classroom experience; to accommodate the slope, the extension is built on a timber deck looking out into the woodland, establishing the concept of the classroom as a tree house.

The extension has allowed the school to expand to single form entry. The new accommodation consists of a series of indoor and outdoor spaces; an additional classroom, a special educational needs room, a library, an extended hall, new toilets, and a wellington boot and outdoor equipment store. The new classroom and library enjoy views out into the surrounding tree canopy. Covered external deck areas can be used as outdoor classroom space as well as for informal play.

A key external feature is the habitat wall, a thickened wall on the east elevation which is constructed as a framework to accommodate different types of biodiverse habitats for birds, insects, small animals and plants.