A group of leading ‘retrofitters’ gathered at NLA to show how they are leading the way when it comes to reworking tall buildings from the 1950s, 60s and 70s. John Robertson, director of John Robertson Architects began with a look at the 1956 Great Arthur House, which won NLA’s retrofit category in its awards this year.

The Grade II listed building is part of the famous Golden Lane Estate and was a scheme Robertson studied as a student. ‘I was impressed with it then and never thought I’d be privileged to actually get involved with it’, he said. Golden Lane was designed in the early 50s by Chamberlin, Powell and Bon, the trio founding their firm on the award-winning scheme. It features a ‘Le Corbusian sun-scoop’ at the top of the building, with an ‘economy’ to the 120 one-bed naturally-lit studio apartments, each with two means of escape and windows by Quicktho, which also made them for Routemaster buses. One of the main challenges JRA had was in doubling the load of the curtain wall, recladding it with a panel system while the residents were in situ, and generally restoring what had become ‘a bit of a sorry tale’. Robertson said he most enjoyed the ‘forensic’ approach his practice employed to a striking modernist building, but with many architect residents and the building being of such historic note, they were under constant scrutiny.

At South Bank Tower, meanwhile, AKTII director Marta Gallinanes Garcia said the ‘rejuvenation’ of the Seifert building had been the engineer’s key aim, pushing the existing structure to new limits with the addition of 11 extra floors to the 30 existing without incorporating new foundations or wholesale strengthening of the whole vertical structure . Originally offices, the scheme was converted to residential and the engineers enabled the extension in part by adding four storey outrigger walls to spread load across the scheme. ‘It’s a proper urban tower now’, she said. ‘It looks more slender, and has the right proportions’.

Finally, Anne Schroeder, Associate, Fletcher Priest, described the Angel Court project; 25 storeys of office with retail on the ground floor in the City of London, refurbishing a tower from the 1970s and being one of the first in the Square Mile to achieve BREEAM ‘Excellent’. The building, now with lighter, glazed cladding with a 1mm ‘microfrit’ ceramic dot, uses a third of the energy of its predecessor, said Schroeder, which also suffered from insulation issues and ‘confused access’ as well as narrow and insufficient floorplates. Amenity spaces in the new scheme include a bar on level seven accessible to all the tenants in the building which leads onto a large landscaped terrace designed by Vogt.

During discussion Austin Wikner, Director, WSP said that when it comes to retrofit we think about what we should, do (including global commitments to getting to net zero), could do (including stopping using gas boilers and such like to improve air quality), and how we go about working with tall buildings. There are opportunities, he said, for both physical and ‘human’ elements such as wellbeing improvements, and also the potential to make them more ‘fun and exciting’, partially with smart technology. Perhaps, he suggested, the retrofit could in fact make better use of offsite and modular to help against the significant logistical and physical challenges associated with such work, and particularly in tall buildings. With the rise of wellness as an issue, it was also important to look to creating more amenity space, he added. ‘Let’s give a bit more back, and put some more into the community’.