A sequence of tile murals celebrating the white heat of British technology – the teleprinters, wiring circuits, spiky aerials and banks of switching gear which constituted 1960s telecommunications – has been listed to preserve it as the grim grey building supporting it faces demolition.

The murals – in smoky blue, brown and green – were the work of Dorothy Annan, who was commissioned in 1960 at the enormous cost of £300 a panel to create them for the Ministry of Works, to decorate a huge new telephone exchange in central London.

Annan collected scores of images of communications kit, and visited General Post Office buildings for inspiration before designing the murals, which include stylised representations of pylons, cables, telegraph poles, cabling, television and radio aerials and generators. She visited the Hathernware pottery in Loughborough and hand-scored her designs onto each wet clay tile Her brush marks can be seen in the fired panels.

When it opened in 1961, the purpose-built Fleet Building on Farringdon Street – designed by Eric Bedford, architect of the Post Office Tower (now known as the BT Tower) – was the largest telephone exchange in the capital.

The IT revolution has made thousands of such buildings redundant across the country, and the Fleet Building has been a derelict eyesore for years. It is now owned by Goldman Sachs, which is believed to be planning to clear and redevelop the site.

Heritage minister John Penrose has not listed the building itself – although grim, it has its admirers – which probably means the tiles will be carefully dismantled for storage and reuse.

Annan, who died in 1983, exhibited with the leftwing Artists International Association, and once featured in a morale-boosting wartime show in an air-raid shelter beside work by Augustus John.

Her paintings are in many national collections, but she was also known for her tile murals, many of which have been destroyed in recent decades. Only three of her major public murals are believed to survive – the largest single example, the Expanding Universe at the Bank of England, was destroyed in 1997.