Despite his name and stylistic preferences, this particular Robert Adam is unrelated to his 18th century Scots-born namesake. That's just a happy coincidence. There's another difference, too: our 21st century Adam is designing his new Scottish settlements in such a way that modern architects can build alongside the traditionalists without anyone throwing buns at each other. How does he manage this? The secret is something that has been causing quite a bit of anguish in British architectural circles lately. The phrase is "design codes".

Adam has been called in by Forth Ports, owners of the Leith and Granton harbours, to contribute to their part of a huge string of waterside developments now being planned that will connect booming Edinburgh with the sea. This means that Adam is in charge of two new townships on the Forth at Leith's Western harbour and Granton. When you add in homes already being built there by Edinburgh architects, the two schemes add up to 6,400 homes - apartments and houses - plus shops, offices, primary schools, parks and the like - over a total of 180 acres. Total cost? If you add in the business developments as well as the residential bits, it comes to well over a billion pounds or $2bn.

That's just the start. Forth Ports also have another 18,000 homes sketched out in a third masterplan by architects RMJM for another section of the Port of Leith. On March 3 they formally launched all three schemes under one marketing banner: Edinburgh Forthside. With an eventual population of 24,000, Edinburgh Forthside plus its neighbouring developments will be the equivalent of a large town such as Kirkcaldy, on the opposite side of the water. Adam's Western Harbour development alone has a park in it the size of Edinburgh's Princes Street Gardens.

Many thousands more homes will be built on the adjacent "Waterfront Edinburgh" and "ForthQuarter" schemes by other landowners on former industrial and gasworks sites in Granton. All told, there will be a steady stream of around 1,000 new homes a year of all types being built here over the next 20 years. Many of them will be built on land reclaimed from the sea - the biggest such reclamation scheme in Europe outside the Netherlands.

Terry Smith, property director for Forth Ports, does not see this volume of new housing as a problem. "City planners reckon that Edinburgh needs 5,000 new homes a year just to meet demand," he says. "So we don't think we're over-egging it."

<

Housebuilders are already busy in Leith's Western Harbour. Right next to Adam's forthcoming scheme, high-rise apartments by Bryant Homes, FM Developments and Gregorshore are selling for between £190,000 ($358,000) for a two-bed flat and £700,000 ($1.3m) for a 3-bed penthouse. Developers are now buying up plots in Adam's masterplan and will launch their sales operations later in the year.

Adam has designed dense streetscapes of generally low-rise buildings in Leith and Granton. As the housebuilders move in with their own architects, he now has to sit back and watch others grapple with his ideas. The builders have to conform to Adam's strict design codes, and he will be policing them. Modern or traditional doesn't matter, says Adam, so long as people stick to his mandatory guidelines on size, proportions, materials and how the buildings relate to the streets. For instance: no all-glass facades are allowed. It's as if his parts of the Edinburgh ports are already conservation areas, before anything is built. And Adam has clearly had fun getting his staff to computer-design indicative modern homes on the masterplan as well as contributing his characteristic traditionalist pencil drawings.

"It's not about building style, but the texture and quality of the district," says Adam. "We can't make codes that guarantee good architecture - but they can prevent bad architecture from spoiling the place."

This is all just a bit like Edinburgh's existing 18th and 19th century "New Town", which was planned by one architect - James Craig - but built by many hands. There the resemblance ends, however: the New Town was built in fits and starts over a century whereas Adam's two smaller townships will be there in six or seven. Adam is also allowing a lot more variety in his homes than you encounter in the stern uniform grid-plan of the New Town. He is inspired, he says, not just by Edinburgh - the medieval fishbone-pattern Old Town as well as the grid layout of the New - but also by the cities of continental Europe.

"It's a really interesting thing to do," says Adam. "You don't have to do clever tricks. You just have to look at what has worked before, and learn from it."

The Adam approach -with the housing broken down into smaller blocks, built on more streets per acre than a typical high-rise scheme - is more expensive to build than its neighbours. But he has found that his approach adds far more market value than the extra cost when housebuilders start bidding for the sites.

By and large, Adam has got Edinburgh's modern architects on side - by the old-fashioned expedient of going to talk to them and asking their opinions. He has met one or two, he says, who try to get round his design codes, and to them he just says no. He knows what he wants this place to look like. "There's a moment, when you're dealing with something like this, when things fall into place and it takes on a life of its own. We've created a framework to protect the whole place. We're able to describe it street by street."

Time will tell, but Adam is genuinely fired up over these two projects. Not only will traditional and modern homes exist cheek by jowl in his settlements, but the districts planned by other architects nearby will allow a delicious amount of compare-and-contrast in the years to come. I'm prepared to bet that homes in Adam's townships will quickly start to sell at a premium. They just feel more like bits of a real city, somehow. As he says, it's all about texture.

Edinburgh Forthside website: www.edinburgh-forthside.co.uk
Robert Adam architects: www.robertadamarchitects.com