James Ashton: Head offices are more than simply bricks and mortar

All of this makes BT’s decision to exit its headquarters close to St Paul’s timely. Here is a company that encourages customers to transform themselves with its internet services without having ever fully cast off its own public sector, monopoly mindset and the concrete monolith it inhabits.

BT’s move will be an acid test of whether a new building can bring about a new attitude. On a smaller scale, another overdue relocation is the Institute of Directors which I’m convinced will never modernise until it has left behind the chintz and flummery of its Pall Mall base.

“If walls could talk,” the saying goes. They frequently do because how a firm houses itself speaks volumes. The headquarters of South African financial services group Old Mutual was already a ghost ship when I interviewed boss Bruce Hemphill there last year. The company is being carved up and the dilapidated office — never liked by senior management — had come to symbolise the annual £180 million of wasted central costs for a firm that should never have brought its primary share listing to London. In the Antony Jenkins era, Barclays plastered his mantra of RISES values — respect, integrity, service, excellence, stewardship — across the reception and in the lifts at its Canary Wharf tower. It smacked of a company trying too hard to persuade its staff and critics it had changed.

Further back, Sir Clive “Mr 20%” Thompson ran ratcatcher Rentokil Initial from a stately home. It might have been inherited from a predecessor, but the base spoke of a management layer that remained well-upholstered, aloof and slightly old-fashioned while staff further down the chain burnt the furniture to keep up with growth targets.

In contrast, a trip to see Kate Swann when she ran WH Smith reassured: the retailer’s old office just off Oxford Street was tatty in the extreme — just like its shops. Talk about living the brand.

By splashing millions on new headquarters, a company is usually inviting investors to sell the shares. That should certainly have been true for Fred’s Folly, the nickname for the gleaming Royal Bank of Scotland base built on the site of a former Edinburgh mental hospital whose construction was closely overseen by Fred Goodwin. However, the same was not the case for Sky which created a corporate empire to match the ambition of its west London property empire — the closest thing the UK has to a Google-style campus.

Headquarters project power — or else there would be no uproar when Unilever proposed moving to Rotterdam. It is instructive that some of the most forward-looking companies — including Facebook and Apple — have resisted the urge to downsize and instead built giant fortresses to call home. At their heart, headquarters remain about the people that use them day in, day out.

To forget that is to forget what makes a business great in the first place.