The project titled College Square, was developed by Hartley and Johnson while completing the final year of their architecture degrees at Central Saint Martins (CSM), during their Spatial Practices programme.
They proposed creating a variety of reconfigurable outdoor furniture for an area of Croydon, south London, which could be used by members of the public as a spot for socialising and recreational activities.
"The main inspiration for the project came from the different groups of people we envisioned using the space," Hartley told Dezeen.
"We developed the project as a 'kit of parts' in a language that could be adapted and implemented into different sites, as a response to the increasing number of vacant spaces in the borough."
The pair, who were supported by fellow CSM graduates Mina Fouladi and Olivia Sutherill, were invited to fully realise their proposal as part of Meanwhile Croydon – a council run programme that employs public installations and cultural events to revitalise neglected areas of the borough.
Croydon Council's place making team undertook detailed design and installed the project in a small square in front of Croydon College.
A couple of freestanding steel-frame archways bookend the site, which are topped by the project's name in red block lettering.
These were loosely informed by the shape of Arnhem gate, an old brutalist gateway near to the college where Hartley and Johnson initially considered situating their design.
Dotted in between are a selection of chunky, wood-clad furnishings painted bright green or baby pink that can perform a variety of functions.
The boxy volumes can be reconfigured to create performance stages or tiered blocks where visitors can sit and gather and have steep ramps that can be slid down by skateboarders.
"Each of the blocks can be configured and used in a multitude of ways, meaning the space can evolve and change along side the events that take place there," explained Hartley.
In 2017 design studio Raw Edges created a collection of oversized concrete armchairs for London's Greenwich Peninsula. Coming as part of the area's redevelopment scheme, the seats can be rearranged so that passers-by can sit, lay down, or climb over them.
Photography is by Ruth Ward.
Project Lead: Croydon Council
Collaborators: Central Saint Martins
Designers: Fiona Hartley, Ellie Fox Johnson
Supported by: Mina Fouladi, Olivia Sutherill
Detailed design and mentoring: Croydon Council Placemaking Team