Architecture: Hail to the chief of neo-Classicism: Thomas Jefferson's ideals laid the foundations of architecture for the US, as well as its constitution. Matthew Hoffman assesses his legacy

William Jefferson Clinton's inaugural journey ends today in the grand climax of his presidential oath on the terrace of the Capitol in Washington; but it began privately on Sunday with a tour of a country house near Charlottesville, Virginia. The builder of that house was Mr Clinton's namesake and one of his inspirations: Thomas Jefferson (1743-1826), chief drafter of the Declaration of Independence, third president of the United States, founder of the Democratic Party - and his country's first important architect.

Mr Clinton is keen to associate his presidency with the life and ideas of his predecessor. At a question-and-answer session with schoolchildren after his tour of the house, he spoke knowledgeably about Jefferson's belief in freedom and progress, his faith in individuals solving problems, and his certainty that 'life could be better'.

Although Mr Clinton did not mention it, the house itself, Monticello, is a metaphor for the larger accomplishments of Jefferson's life. His private homes brought the Palladian country house to prominence in the American South, and his public architecture - including the state capitol at Richmond and the University of Virginia, together with his overseeing of the development of the new capital city of Washington - set the neo-Classical pattern that has dominated US government buildings ever since.

Students of free speech, visionary democrats, connoisseurs of 18th-century intellectual history and the new president of the United States can all learn from Thomas Jefferson. But does he have anything to teach contemporary architects and their patrons? Are there principles underlying Jefferson's work as an architect, incorporating his aesthetic and political vision, that are as relevant today as his legacy to constitution-makers?

Born into a frontier farming community, Jefferson conceived the idea, in his mid-twenties, of building a Palladian house on the top of a mountain on property he had inherited from his father. Throughout the rest of his long life he worked on this house, pulling down some parts and adapting others as his artistic ideas and domestic needs changed. He left a record in bricks and plaster of the civilising mission he had taken up during his lifetime.

Jefferson built in the Palladian mode: it was still fashionable in his day, and he had an eye for fashion. While ambassador to Paris in the 1780s, he observed that 'all the new and good houses are of a single story' (his spelling); and on his return to Virginia he pulled down much of his own two-storey house, with its double portico, to construct a new facade giving the illusion of a single-storey house.

But Jefferson had much more than fashion in mind when he was designing buildings. He saw architecture as an open book that could provide 'models of taste' for his fellow Americans. In both his domestic and public architecture Jefferson emphasised comfort and convenience, but he based his designs on 'antique' models.

The Virginia state capitol at Richmond is a modified version of the Maison Carree at Nimes, the most perfect surviving Roman temple. Linked classical pavilions and a rotunda, adapted from the Pantheon in Rome, form the core of his University of Virginia, specifically designed 'to serve as specimens for the Architectural lecturer'.

Roman forms had a particular appeal for Jefferson: they pointed to the achievements of the Roman republic, an example from antiquity that had inspired Jefferson and his contemporaries in their endeavour to create a democratic republic in North America.

One biographer, speaking of Jefferson's justification of the rights of colonists to rule themselves, refers to an 'appeal to the past on behalf of modern principles' and observes that this form of argument 'was thoroughly characteristic of him'. It was also characteristic of his architecture. None the less, his blending of the antique and the modern was far removed from the jesting and ironical use of Classical motifs in the Postmodernism of such architects as Robert Venturi or Quinlan Terry. Jefferson wasn't joking.

Jefferson's architectural genius was firmly rooted in the Classical style, but there are underlying principles that could be incorporated with profit in our own commissions for public buildings. Some of the lessons must be negative ones: freedom does not mean disorder; modernity does not mean the debasement of the past; and functionalism does not mean the abandonment of style.

More positively, words that were common currency in Jefferson's lifetime - civilisation, elegance, virtue - have for too long been pronounced only with embarrassment. Together with 'liberty and the pursuit of happiness', they stood for ideals that must be invested with new forms of physical expression if we are to be true to the vision, both aesthetic and moral, that created modern democracy.

A walk around the University of Virginia, which Jefferson established in 1819, illustrates a failure to learn from his vision. The campus today is a profusion of undistinguished buildings of various periods strewn over the hills with little apparent relationship to one another. Jefferson's beautiful 'academical village' - a visible combination of pedagogic purposiveness and architectural ingenuity - lies at the heart of the university, and yet has failed to influence its higgledy-piggledy development.

If Jefferson were alive today, what type of architecture would he favour? He loved an elevated view, lots of light, innovative engineering, superb craftsmanship and Classical proportions. My guess is that he would be drawn to the Modernism of Frank Lloyd Wright or even Mies van der Rohe. Not for him the enlarged copies of Cambridge buildings to be found at the University of Chicago; nor the cult of sincerity to be found in Richard Rogers' exposing of a building's innards to public view.

'How is a taste in this beautiful art (architecture) to be formed in our countrymen,' Jefferson asked his fellow statesman James Madison, who succeeded him as president, 'unless we avail ourselves of every occasion when public buildings are to be erected, of presenting to them models for their study and imitation?' It is Jefferson's inspired accommodation of old achievements to new demands, no matter how revolutionary, that President Clinton should continue to study and imitate, in his architecture as well as in his politics.