Biodiverse Green Roof

- Bradford University, UK

Client Bradford University

GB Building Solutions / Geogreen

Consultant Farrell and Clark and Margaret Twigg Landscape Design


Biodiverse Roof Systems




– Significant contribution towards BREEAM ‘Excellent’ rating
– Replaces lost habitat & enhances biodiversity
– Complete ABG service from design support to installation.

Project Description
The new build £5.2m re:centre at Bradford University comprises a four-storey, 2,000m² building, containing workshops, business units, an open-plan office and a multi-function space, all of which provide learning facilities and teaching resources aimed at promoting sustainable living. The re:centre has been designed to the University’s target driven sustainability specification, delivering the world’s highest ever pre-construction BREEAM rating of 94.95% at award. The buildings design showcases several highly sustainable low energy features, including a full height sun space providing natural ventilation in the summer and heating in the winter, PV panels, hempcrete walls, rainwater harvesting and a biodiverse roof system.

The Challenge
Given the nature of the project it was important that the building and it’s construction embraced sustainability from the beginning. It was decided that all space, including at roof level, would be used to its maximum potential. It was critical that the Biodiverse system provided the necessary contribution towards achieving this and the associated BREEAM credits. The biodiverse system was required to replace lost habitat (LE04: 2 credits), enhance ecology and increase the number of native or beneficial plant species present on site (LE05: 3 credits). This is relevant to BREEAM within the Land Use and Ecology section, although it does also directly impact other considerations including flood risk mitigation and indirectly influences the categories of thermal comfort, acoustic performance and responsible sourcing of materials & waste management.

The Solution
ABG worked closely with the landscape architect to create a system to meet the stringent criteria. The green roof installation comprised a wildlife pond planted with native marginal plants, a native wildflower area, matrices of sedums, grasses and herbs, insect hibernaculas (including bird feeder tables, insect houses, pebble areas and coiled hemp rope) and specially designed features to encourage the development of flora and fauna on the roofing area. A lightweight ABG Biodiverse growing media was used to minimise the roof loadings whilst providing a nutritionally rich base for the specially selected vegetation. Beneath this surface finish ABG Roofdrain drainage geocomposite was used to create a free-draining void that also allows for the storage of collected rainwater to irrigate planting during dry periods.

The ABG Service
ABG’s in-house technical green roof expertise & on-site installation experience provided the client with a solution that maximised the roof’s contribution to the development.

Additional information