Shedkm has reimagined a notorious brutalist block as temporary housing – saving 4,000 tonnes of carbon emissions in the process
Zodiac House in Croydon is probably best known as home to the characters Mark and Jez in Channel 4’s magnificently bleak sitcom Peep Show. Until recently, the reality was even more depressing. Built in the 1960s, the four-storey office block had been vacant for half its life.
“There was evidence of water leakage, stalactite formation and heavy corrosion where openings had been made in the slabs,” says Ella Flint, architectural lead at architect Shedkm. “But generally the size of the floor plates was really good.”
Working with developer Common Projects, Shedkm has restored the complex – highlighting the best features of its original brutalist design – and adapted it into temporary council housing for homeless families. There are 73 flats in total, ranging from one to three bedrooms, as well as a communal residents’ lounge in the former undercroft. The windswept tarmac forecourt has been dug up and replaced with a 1,000m2 community garden and cafe.
Structural engineer Whitby Wood began by undertaking a condition survey, which found that the waffle slabs and in-situ concrete frame were in a fair state, given the building’s age and type. A loading survey and heat map analysis showed where openings could be most easily made, and where services and heavy items were best placed. “That was really key for us to understand what we could and couldn't do with the building,” says Flint.
The building wraps around a courtyard and an eight-storey residential tower, which will be part of the second phase. Its regular grids and large floorplates lent themselves to a double bank of mainly single-aspect apartments on either side of a central corridor. Shedkm adopted a fabric-first approach, installing insulation and replacing the Crittall-style single-glazed windows with contemporary double glazing. U-values for the flats have been measured at 0.18 for walls and between 0.18-0.30 for floors. A pragmatic fit-out strategy has prioritised durable, cost-effective materials that should make it easier for the council to maintain.
The main insertions into the structure are two new residential units with balconies at second-floor level beneath the tower. A covered passage below has also been filled in to create an entrance and communal area, and the main staircase and balustrade have been restored.
The original facade had a strict rigour, organised around thin precast vertical fins and horizontal pebbledash spandrel panels and in-situ concrete slab edges. Shedkm was keen to maintain as much of this as it could. On the upper levels, it has limited interventions to cleaning the masonry and updating the glazing. Aluminium frames and solid panels are in light grey, with occasional panels in a strong green-blue. “The building is naturally a warm grey tone, so we wanted to desaturate that, but also add feature moments that would create contrast,” says Flint. “By giving the facade life and colour, it reactivates an iconic yet tired-looking building.”
At the double-height ground level, the pebbledash panels have been removed to instil a sense of hierarchy to the facade. Pebbledashing has also been replaced with a geometric grid of glazing above the projecting concrete canopy of the main entrance. This acts as a bold, modern backdrop to six of the concrete zodiac murals that give the complex its name. (The other six panels are on the garden facade, in front of a mix of solid blue-green panels and original pebbledashing.)
Shedkm says that reusing the structure preserved 3,940 tonnes of CO2e, while avoiding reconstruction prevented a further 2,624 tonnes of emissions. That’s not even taking into account the eight-storey tower, which may have had to be demolished at the same time but is now being renovated in the next phase of the programme.
Ella Fint spoke about Zodiac as part of the Concrete Centre’s Sustainability Series of webinars. Watch back at concretecentre.com/CPD-Events.aspx