Sundolitt XPS specified for living roof at The Sill - Northumberland National Park’s new visitor attraction

Sundolitt’s XPS insulation has been specified for Northumberland National Park’s new and exciting National Landscape Discovery Centre. Known as The Sill, this striking new visitor attraction, near Hexham is inspiring people of all ages to explore the landscape, history, culture and heritage of Northumberland.

XPS 300 grade was specified by JDDK architects for the innovative living roof which is fully accessible with a walkway and platforms, providing a vantage point across one of the UK’s most magnificent landscapes and the UNESCO World Heritage Site of Hadrian’s Wall.

In total 1900m² was installed, built up to a thickness of 270mm with flower-rich native Whin Grassland planted on top. Sundolitt’s XPS material was chosen as a cost effective solution that could withstand the heavy loads of soil and planting as well as constant footfall on the roof. XPS is also water resistant and not affected by water allowing the green roof to thrive.

The Sill is the UK’s first dedicated National Landscape Discovery Centre. The project, led by Northumberland National Park Authority, was supported with significant funding from the National Lottery players through a £7.8 million grant from the Heritage Lottery Fund (HLF).

The Sill’s purpose is to provide a gateway to enable more people to experience the National Park. It has been designed to promote understanding of some of the country’s finest landscapes. The centre is open all year round and offers a wide range of facilities including YHA Hostel accommodation, exhibition space, a rural business hub, retail facilities and a café.

The creation of the living roof with Whin Grassland habitats is a unique feature of the visitor centre. The soil was made up especially for this project and based on soils found in abandoned whinstone quarries locally. Species rich, small slow growing grasses and flowers were sown a few months prior to the centre opening in July and although the vegetation will initially appear sparse, it will thrive on its XPS base with minimal maintenance.

Stuart Evans, Head of Corporate Services for Northumberland National Park Authority, said: “Sundolitt’s XPS insulation provided the National Park Authority with a solution to confidently progress with the installation of a publicly accessible local grass and wild flower roof to take the weight of over one metre of soil and drainage substrata, whatever the weather. This is the first time such a facility has been designed into a building in the UK. The living roof is the standout feature of the building and is loved and appreciated by our visitors”