We walked round the back of Stanmer Park today, to see the green roofs at Northfield, the campus extension of Sussex University.

Approaching Northfield student housing from Stanmer Park

Built between 2010 and 2013, the campus features a wide range of features to minimise its environmental impact and running costs. It’s location was controversial – north of the main campus, on farmland, and tucked right up against the South Downs National Park, a Local Nature Reserve and a Site of Nature Conservation Importance – so it particularly needed to blend in and demonstrate a sustainability ethos.

“The complex has 272 secure bicycle parking spots (one for every three residents) and eight car parking spaces, four of which are for wheelchair users.

A number of energy-efficiency measures include green roofs (which increase insulation and provide greater biodiversity), low-energy lighting, double glazing and recycling facilities.”

15 steep sloping green roofs are an obvious feature of Northfields student housing

The development won a Green Apple Sustainability Award, and received a Breeam Excellent rating.

However, there are problems with the green roofs, which are unusual in being pitched. They look like they are struggling and dying in places.

The planning application noted that “The use of green roofs will be beneficial in blending the development into the landscape from longer views and as an ecological compensation for developing an existing greenfield site.”

But it also said “The green roof treatment to the buildings will, if successful, further minimise the visual impact of the buildings as well as providing additional habitat. Sedum roofs often dry out after 2/3 years so there is a concern that the oversown sedum treatment may be short lived and not be fully fit for purpose, and that a slightly deeper root run might provide a more effective substrate on which to establish a chalk downland type flora.”

Although the green roofs certainly do help the development blend into the surrounding countryside, it seems like the fears about the longevity of the Sedum have been realised. Elsewhere in Brighton & Hove failing green roofs have been successfully refurbished.

For example, green roofs have been part of the University of Brighton campus for some time. At the Checkland Building, green roofs have recently been restored following some initial problems with the planting and the limited amount of growing medium installed.

“The Checkland Building has been environmentally designed, incorporating night time cooling, natural ventilation, and green roofs to insulate the building from heat loss in winter and heat gain in summer.  As the university sits within the South Downs, a recognised area of chalk grassland (calcareous), the creation of flower rich green roofs provides an important enhancement within the Checkland Building for invertebrates associated with such area.”

The Huxley Building and Falmer Sports Centres also have green roofs – these have suffered similar problems to Checkland and have had to be refurbished. Organic Roofs have the contract for this work, and have refurbished the landmark Velo Cafe green roof at the Level in Brighton, which is now thriving.