Roots In The Sky will be London’s first office building to deliver a 1.4-acre urban forest rooftop with extensive access for the local community and general public. The project will deliver community space, accommodate collaborative neighbourhood uses, a rooftop restaurant, bar, swimming pool and terraces, all alongside one of the largest roof gardens in Europe, providing cooling shade, fresh air, and access to nature. The building will make a significant contribution to London’s ambitious targets for greening, biodiversity, and sustainability — providing space for nature, not just humans.
The radical repurposing of the former Blackfriars Crown Court into a next-gen workspace will deliver 385,000 sq ft of contemporary and sustainable office, commercial and community space. The existing 1960s structure provides the blank canvas to develop a forward-thinking office building that replaces an urban heat island with a genuinely living rooftop.
The project team have designed a lightweight hybrid steel and CLT frame, reducing embodied carbon and providing the ability to support an urban forest with 1,300 tonnes of soil. Internally, the building’s intuitive environmental strategy not only exceeds the highest sustainability accreditations but seeks to further enhance occupiers’ wellbeing with a passive ventilation strategy, openable windows maximising access to fresh air, and a full-height feature atrium which facilitates the extraction of waste heat from the building.
We have covered our cities in concrete — how do we respond? The rooftop and building landscaping, designed by landscape design practice Harris Bugg, exceeds the urban forest criteria set out by the UN with canopy cover of 23 per cent, provided by over 100 established trees and 10,000 plants. Technical aspects of the roof are also ground-breaking, such as the design of a passive water capture system which will irrigate the planting above on demand, reducing the net external water demand of the building.
Uncertain, extreme weather is facing London; this building was designed with adaptive flexibility in mind. An openable facade provides natural ventilation, and urban greening of the terraces gives shade in summer, reducing local temperatures by up to 8°C.
An all-electric building, wastewater heat recovery and air source heat pumps further reduce reliance on the grid.
Embodied carbon has been thoughtfully considered in material selection, utilising timber within a steel frame with high recycled content. Rainwater is recycled for irrigation, alleviating pressure on water infrastructure, with 1,300 tonnes of absorbent soil providing a natural water buffer, protecting against flash flooding.