He is a millionaire property developer, and hasn't taken up the post yet. But already he has turned down pounds 30,000 a year for two days' work a week. Of course, it will be more than two days, even if he plays down the number of projects he will be reviewing. He is not formally employed until September when the Commission for Architecture and the Built Environment is launched. But he is already getting stuck in, in his role as chairman.
Mr Lipton's approval of the Great Exhibition of 1851 gives a clue to the influence he will have on Government. "Damn good value, a whole block of educational buildings, from the Albert Hall to the Victoria and Albert Museum, as well as the world's greatest glass palace built for only pounds 51,000, within nine months. Everyone understood it, loved it and it was very hi- tech," he says.
Mr Lipton owns a set of Paxton's drawings, in small scale, which he treasures. Paxton is his hero. This is a good sign; he does not underestimate the architects' role in the success of any building scheme. "I can demonstrate that successful architectural streets are successful financial streets," he says.
A landscaper, patron of the arts, and developer of Broadgate where he landed a Richard Serra sculpture in a public space to amuse the passers- by, Mr Lipton is also a millionaire property developer who has gone into boom time and then out again throughout the 1980s.
He reinvented himself on various big commercial developments. His "personal problem" as he calls going broke in from 1994 to 1995, was on the Ludgate kilometre of tunnel with its buildings on top. The infrastructure needed pounds 140m upfront and with the market falling away there was nothing to let and no income.
The appointment of a property developer to advise on architecture suggests "less cul- ture, more vulture". "You don't know Stuart," says David Rock, the outgoing chairman of the Royal Institute of British Architects, who helped draw up the guidelines for the commission. The one thing a property developer must develop is ruthlessness in business. Yet Mr Lipton has always supported good contemporary architecture as much as showing a good head for business.
Private Eye called him "poacher turned gamekeeper." He certainly knows both sides of the fence, but he insists that reviewing projects for the built environment will not pose a conflict with developers. An infamous spat developed over the mayor's assembly building, in London, with Blackfriars backing Will Alsop for a revamp of Victoria House, in Bloomsbury, and CIT, a foreign-backed investment company, supporting Norman Foster's design. Mr Lipton's feasibility study on the CIT site near the Tower of London was seen as having helped Foster win. "My job was to get planning permission. I have done the job I was paid to do, and I am leaving them with a good master plan and a well thought-out scheme. If CIT wants us to do another piece of work we will think about it."
The proposed, big elliptical glass building that will be the new home of the mayor's assembly, looks like a giganti car headlight and a bit of an eyesore on the river strobing the Tower of London. "But be patient with it," Mr Lipton urges. "Norman is very good. He'll change it. He never stops until he gets it right."
Mr Lipton is in Berlin today to watch Sir Norman pick up his Pritzker prize, the most influential and prestigious award in the business. Unabashed enthusiasm for the architect, and for Richard Rogers - Lord Rogers's brother, Peter, is project director for Lipton at Stanhope - has meant dealing with accusations of croneyism.
But he says: "I'm proud to be in the Foster-Rogers camp. It's the only camp at the moment showing a considerable mount of care. Other architects are getting there - Richard MacCormac, Allies and Morrison, Lifschutz Davidson, and Ian Ritchie and numerous others. The challenge is to make the club bigger, not smaller.
"Once you get into working with people to see how art and science go together it need not cost more. I'd rather be strategic and look at a limited number of projects in detail than review hundreds." This will be tough for Norman St John Fawsley, retiring chairman of the Royal Fine Arts Commission, to swallow. One of the big criticisms of the RFAC as a moderator and as a Government advisory body, was that it reviewed too few buildings - there were about 400 a year. And the Architecture Commission should be moving into its premises, even as Lord Fawsley hands out the prizes at the Savoy today for the Building of the Year Awards (last year's award went to Windsor Castle's unimaginative and painstakingly executed restoration of the fire-damaged St George's Hall).
Unafraid to speak his mind on aesthetic issues, Mr Lipton roundly condemns the "My Little Pony" school of decoration that, he says, produced the Hyde Park gates, commissioned in honour of the Queen Mother. "They're awful," he says. "I often go by them and think what a wasted opportunity. The funny thing is that Giuseppe Lund who made them - or at least, half of them - made, for me, the Victoria Station gates, those great big chaps at the Solomon building. And they're honest, modern pieces, I believe.
"But you always need a well-informed client with a clear brief. It's not a purely financial issue. My attitude is that if you can't afford a design, simplify. And always do a proper site analysis."
A little head mask sculpture by Naum Gabo, which sits in the Tate gallery is a good illustration of this kind of tailoring. "Who would believe that you could take a single sheet and make it into an artwork ? The message that has got to be got across is that it is not really about money in the end. It is about real ingenuity and skill, and, dare I say it, love?" he says.