London might be known for its royal parks, and other ground-level green spaces, but its roof gardens are on the rise – literally.

According to a new study, the capital now has 371 acres of high-rise garden space, more than cities including Tokyo and Singapore, where the roof garden movement began. If placed end to end, London’s gardens atop apartment blocks, offices and other buildings would cover a bigger area than Hyde Park.

As the study by the European Federation of Green Roof and Wall Associations (EFB) explains, the trend is being driven by architects, planners and developers looking for innovative ways of creating outdoor space.

Over time, the gardens have become increasingly elaborate, incorporating waterfalls, swimming pools, lawns and – in one case even 100 trees. But there’s an environmental aspect to the trend too, with the gardens helping to combat climate change and providing havens for wildlife.

Developers of new apartment blocks use their landscaped roofs as a key marketing tool. Islington Square, for example, on the site of the former North London Royal Mail sorting and delivery centre, has penthouse flats that come with their own private roof terraces.

According to Dusty Gedge, president of the EFB: “While there is a degree of evidence that green roofs can remove particulates associated with air pollution, it’s the space they provide for people that is more important. Buildings make up the majority of a city’s footprint.

“These buildings should be the perfect platform for parks, gardens and unofficial nature reserves. In this way, people and wildlife have access to greenery. And where there is greenery, the air is likely to be fresher.”

Read more about this story in Time Out and if you’re happy with heights, and fancy the green roof experience, check out the website’s lists of London’s best rooftop bars and gardens.