Biodiverse Green Roof

Roofdrain - Regent Street, Piccadilly, London, UK

Client The Crown Estate

Cawston Specialist Roofing / Geogreen

Consultant Barr Gazetas Architects

Extensive Green Roof Systems





– Encourages biodiversity
– Lightweight and versatile
– Provides heat and sound insulation function
– Improves air quality

Project Description

Part of The Crown Estate’s £1 billion Regent Street regeneration, the new 46,000 sq/ft office building sets a new gold standard for sustainability in a regenerated historic building.

7 Air Street is the first listed building in the UK to receive a BREEAM outstanding rating (94.16%) – the highest award possible from the industry body which judges best practice for sustainability in the built environment. The launch of the green roof marks the first pocket of new green space to be delivered by The Crown Estate as part of ‘Wild West End’, a partnership between London property owners to promote ecology.

The Challenge

The Green Roof Consultancy’s Ecology Report looked to the provision of a green biodiverse roof to address the need to encourage additional species. This achieves an extra credit in category LE04 (Enhancing site Ecology) of the BREEAM Assessment. In order to maximise the local flora and fauna of the roof it was necessary to create as many biodiverse areas as possible, encouraging nature to make its home in specially designed areas. The PV arrays on the roof left limited space for the biodiverse roof and needed to be designed creatively in order to maximise the potential for the biodiverse areas and meet the BREEAM assessment criteria.

The Solution

The ABG Green Biodiverse Roof System included a mixture of plug-planted sedum, sedum cuttings and seeded annual and perennial wildflowers, fitted around the PV arrays and other special features to encourage birds, bats, invertebrates and other wildlife.

ABG Roofdrain was used as the reservoir and drainage base layer to optimise water retention for the vegetation, whilst preventing ponding. Geogreen met the challenge of installing the Roofdrain under and around the PV panels in this tight working environment. Special provisions were made to create hibernacula for the endangered Leisler’s bat and Black Redstart bird. The roof will benefit the whole life cost of the building by providing additional insulation and reducing noise pollution. The roof substrate will also filter dust and pollutants from the air and rainfall, which will help to improve the environment in the surrounding areas.

ABG Green Biodiverse Roof System with carefully selected growing media and biodiverse features overlaying the ABG Roofdrain drainage composite.

The ABG Service

We pride ourselves in our high level of knowledge and expertise when designing and installing green biodiverse roofs. Specialist products in bespoke sizes had to be designed to suit this site.

Contact ABG today to discuss your project’s specific green roof requirements and discover how ABG past experience and innovative products can help.

Additional information