'I can fit into both environments,' beams David Marshall, the IoD's newly appointed PR and lobbying chief, as he reclines on a jokey pinstriped chair in the more modern section of the building. Indeed a PR career spanning a quarter of a century in such venues as 10 Downing Street, Conservative Central Office (CCO) and the corporate HQs of such giants as Unilever and Kingfisher bears testament to that.
Marshall joined late last month with the ethos of DG George Cox in mind, that the body be positioned as more 'sushi bar than pinstriped': 'That's a good line. It's changed so much, my role is to make sure that message is getting out.'
With that as the goal, Marshall is first carrying out an 'informal audit' to look at 'ways we may be able to do things better'.
Under scrutiny will be the central comms team, ways of better communicating with government and MPs and the IoD's regional network.
Marshall has an undisputed enthusiasm for his work, talking speedily and at length of the institute's 'great reputation' and the imminent national launch of its first professional qualification for directors, called the Chartered Director.
As he speaks of his career to date, enthusiasm shines through. As a teenager, growing up in Streatham and fresh out of a Roman Catholic comprehensive education, he decided against university and applied straight to the civil service. He got in and worked for most of the late 1970s in policy roles at the Department of Environment and as a private secretary to a string of ministers.
While on the policy side he worked closely with the PR function, and in his early 20s landed a job as a press officer - where his first job was to promote the controversial sale of council houses.
His career in government went from strength to strength with further promotions leading to a stint in Downing Street's press office. Clearly a fan of Lady Thatcher, he says her fiery, handbagging image couldn't be further from the truth: 'We would talk about normal, everyday things.
My twins had just been born and as she had twins of her own she would often ask how they were. She was very courteous - a good person to work for.'
It was while at Number 10 that he handled media enquiries surrounding the bombing of the Grand Hotel in Brighton in 1984. Understandably on a personal level he describes it as 'a terrible time' but professionally he clearly thrived on the pressure of such intense media interest: 'I don't think of it as pressure. I've been told I exude calmness. I know what I want in my mind and it's a question of getting it done calmly.'
This is backed up by English Heritage corporate comms director Christine Wall who worked with Marshall in the press office at Number 10 and later at CCO: 'He's energetic and a good motivator but calm. He always seems to have a Plan B.'
Following his time at Downing Street, Marshall moved to the Department of Health where his work included promoting the first Aids awareness campaign.
After more than a decade in government he decided to see the outside world, and became the first public affairs manager at the Institute of Chartered Accountants. He was attracted by the challenge of ridding the profession of its boring image. But after 11 months, he says - without a trace of irony - he missed the 'excitement of politics' and joined CCO.
As chief press officer at CCO in the early 1990s he oversaw the media interest in the political demise of Margaret Thatcher: 'It was lump-in-the-throat stuff ... a lot of tears from those who knew her,' he recalls.
He stayed on under party leader John Major and chairman Chris Patten.
A return to government followed, where campaigns included work for the DTI on monopolies and mergers. But in 1998 he felt it was time he tried the private sector and joined retail giant Kingfisher as public affairs manager. A year later, in 1999, he was recruited to head Unilever's government affairs function.
His enthusiasm in extolling the virtue of Unilever's reputation is relentless, even though the firm made him redundant in a restructure earlier this year. But there's no bitterness as he points out that the IoD job came up just five weeks after his departure.
Despite now working at the IoD, the corridors of government will always be with him. When asked how he would like his career to be presented he says, immediately: 'Local boy made good, from Whitehall (tellingly, not Streatham) to Pall Mall.'
1983: Press officer, 10 Downing Street
1987: Chief press officer, Conservative Central Office
1998: Public affairs manager, Kingfisher
1999: UK govt rel manager, Unilever
2002: Director of PA, Institute of Directors.