Green Roofs could grow energy savings for London firms.
A trial is underway to see if planting fruit and vegetables on the roofs of office blocks could cut companies' energy bills and provide a source of fresh food for their canteens.
The six-month pilot of so-called green roofs got underway last month on four London buildings and is expected to realise savings of between three to 10 per cent on heating and ventilation costs.
If successful, the model could be rolled out to hundreds of other office blocks in the capital.
The roofs of Olswang at 90 High Holborn, Cartesian at 8 Gate Street, the Trades Union Congress at 23-28 Great Russell Street, and Mishcon de Reya at 12 Red Lion Square will be covered in plants using a modular vegetation system, in which plants are encased in a "pocket" of recycled material. The system protects the plants, and makes it easier to irrigate and transport them.
Vegetables grown on the roofs will be used in the canteens of the businesses below, while any resulting food waste will be used to fertilise plants. Each roof will also contain beehives to help pollinate flowering plants, vegetables and fruits.
35,000 pilot has been funded by the Greater London Authority (GLA) and inmidtown, an organisation representing 570 businesses in Bloomsbury, Holborn and St Giles.
In a statement, inmidtown said it would look to roll out green roofs across all its members and said that if introduced city-wide, green roofs could save London approximately;
160m in energy costs, while also improving air quality and biodiversity within the city.
Tass Mavrogordato, chief executive of inmidtown, said companies also see the benefit of providing employees with a space where they can interact with each other away from their desks.
"This is a truly innovative project that will not only bring a tangible economic benefit to businesses, but show they care about the environment in which they operate," she said. "Each company will be helping to create a greener, cleaner and more energy-efficient London."