Roots in the Sky

Setting new standards in commercial office buildings

Workspace and public amenity come together in this landmark project.

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Roots in the Sky Project summary

Services provided



Commercial, Offices


UK and Europe


Project story

Bringing both workspace and an array of publicly-accessible social areas to London’s Southwark district, Roots in the Sky is redefining what a commercial development can add to its community. Imaginatively designed with the building’s long-term future in mind, the net zero, next-gen office building will set a new standard in holistic sustainability and urban greening.

Roots in the Sky marks a notable first for the capital, and the UK – in that atop the building will sit an urban forest of 125 mature trees and 10,000 plants. Best of all, a community garden within this glorious green oasis will be open to everyone, delivering real value for the general public and local area. Creating social value is a key driver for Mace as a business, and our role as the main contractor delivering the Roots in the Sky project will provide ample opportunity to do so.

The 1.4-acre rooftop will offer much more than gardens – a restaurant, bar, community ‘barn’ with views across London, and a glass-bottomed swimming pool are all planned too. As sustainability lies at the core of the building’s redesign, the pool will be heated using heat captured from other areas, such as server rooms. The green spaces also fulfil another important role, increasing biodiversity in the locality, with 599.3% biodiversity net gain (BNG).

A project as ambitious as Roots in the Sky provides the opportunity to reimagine a building’s function from all angles, and the advances in sustainable construction in recent years allow for the targeting of the highest environmental standards. The wellbeing of occupants and the needs of the local community can also be factored into the design, and the resulting benefits assessed – Roots in The Sky is targeting an Outstanding rating from BREEAM, a 5* rating from NABERS and, on the wellness side, a Platinum certification from WELL. It will also be the UK’s first SITES-certified building.

Construction on Roots in the Sky is scheduled to complete in 2027. As a fine example of what can be achieved when creative and technical minds meet, this ground-breaking project is set to deliver multiple benefits to the people of Southwark for many years to come, while providing central London with much sought-after sustainable office space.


Project Stats

1,000 tonnes of soil
430,000 sq ft of commercial and community space
25,000 sq ft dedicated to affordable workspace

Points of note

Maintaining and improving

The building’s original 1960s façade is to be retained, with large, sash windows being reintroduced to bring natural light into the workspaces and atrium. The windows will also allow fresh, natural air to enter the building.

Sustainable construction

Sustainability has been a high priority for Roots in the Sky since the project’s inception. Fully electric in operation, the building saves carbon with the re-use of steel from other projects, and reuses energy with an integrated waste energy capture system.