How can Haiti justify repairing its architectural gems when 1.5 million people are living in tents? Steve Rose reports from the country a year after the quake

I am sitting on the verandah of the Hotel Oloffson in Port-au-Prince, sipping coffee and looking out over its tranquil gardens. So idyllic is the scene, you could easily imagine that nothing much has changed here for a century – or at least not since the 1960s, when this white-painted landmark was known as "the Greenwich Village of the tropics" and hosted the likes of Truman Capote, Mick Jagger and Graham Greene. The Oloffson even inspired the hotel that appears in Greene's 1966 novel The Comedians. "With its towers and balconies and wooden fretwork decorations it had the air at night of a Charles Addams house," wrote Greene, referring to the cartoonist who gave rise to the Addams Family, "but in the sunlight or when the lights went on among the palms, it seemed fragile and period and pretty and absurd, an illustration from a book of fairy-tales."

This is not the image of Haiti we are used to – not since the earthquake that struck a year ago today. But you don't have to wander far from the Oloffson to find ruins, rubble and tented cities. The presidential palace is still a collapsed heap, untouched since it became the defining image of the disaster. There are 230,000 dead to mourn, up to 300,000 buildings damaged, and 1.5 million people still without homes. But Port-au-Prince is at least back on its feet: the port, airport and phone network are working again, the potholed streets are clogged with traffic and lined with vendors, and talk is no longer of emergency relief but of reconstruction – and the conspicuous lack of it.

So perhaps it's not inappropriate to remember the prettiness of Haiti's past. The country has an extraordinary architectural heritage, reflecting its status as the first independent, black-led country in the world, and the only nation whose independence was gained as part of a successful slave rebellion.

In that respect, Haiti faces a dilemma: on one hand, there is the need to get the country back on its feet quickly; on the other, there's the desire to preserve what links to the past remain. Yes, architecture is about providing shelter, security and functionality, but it is also about culture, memory and history. In a place like today's Haiti, the former values inevitably take precedence, particularly when there are innumerable charities and NGOs advancing well-meaning but uncoordinated reconstruction projects. Churches and other historic structures have already been toppled or razed, their futures uncertain. This country that has lost so much still has more to lose, but who wants to talk about preserving culture and history when there are still 1.5 million people living in tents?

"Why should we make a tabula rasa out of everything when we have such an incredible history – and artefacts that tell that history?" asks Michèle Pierre-Louis, president of Fokal, Haiti's Knowledge and Freedom Foundation. "I've travelled a lot in the world, and been to lots of poor places where there is a strong sense of history and memory. That is extremely important. It's a link, it's part of your identity."

A former prime minister of Haiti, Pierre-Louis is a remarkable woman with a commitment to what she calls the "historically marginalised" of Haiti. She now includes Port-au-Prince's architecture in that definition, in particular its "gingerbread houses" – so called because of their intricate external decoration. The Oloffson is one of the best-preserved examples of this turn-of-the-century vernacular architecture, but there are some 300 more in the same neighbourhood.

These houses aren't just beautiful. In design terms, they are ideally suited to local conditions: their steep roofs, high ceilings, wraparound verandahs, tall doors and windows (with louvred shutters rather than glass) help keep the insides cool; and, thanks to their flexible timber frames, they have withstood a century of not just earthquakes but hurricanes, floods and torrential rain.

"They stand as evidence that the culture of Haiti differs from the other islands of the Caribbean," says US conservation architect Randolph Langenbach. "Although one can find gingerbread detailing on houses elsewhere, I've seen nothing on the same scale outside the US. But because of the climate, and more loosely interpreted academic styles, they take on a light, open and playful quality that makes them uniquely Haitian."

Langenbach was part of a team of experts who surveyed 200 gingerbread houses last year, after they were added to the World Monuments Fund's watch list of endangered architecture. Less than 5% of them were actually destroyed in the quake, against an average of 40% for Port-au-Prince as a whole, leading Langenbach to believe they could be a model for seismic-resistant designs of the future.

The stock was badly damaged, however, and is in a precarious state, compounded by decades of neglect, although a conservation programme is now in motion, thanks to Fokal. The next stage is to turn one damaged house into an educational restoration project, says Pierre-Louis, with a view to teaching Haitian apprentices the skills needed to preserve the others. "I hope all those people living in tents will be able to come and visit these houses when they are restored," she says, "and know that they are theirs also."

It doesn't stop with gingerbread houses: Haiti is dotted with buildings of a similar vintage. There are 18th-century forts built by the French, and even the British. Then there is the beautiful coastal town of Jacmel. Founded by the French in the late-17th century, it boasts streets of architecture not dissimilar to that of New Orleans, which it is said to have influenced. Though it suffered less than the capital 25 miles to its north, Jacmel was also badly damaged by the quake.

And for those who doubt the role architecture can play in forging national identity, there is the Citadelle Laferrière in the north, the largest fortress in the western hemisphere. Built soon after the country's independence in 1804 by Henri Christophe, a Haitian general who then declared himself king, the Citadelle is an impregnable mountaintop structure whose vital statistics underline not just the Haitians' technical expertise but their determination to never again be slaves: its walls are 16ft thick, its ramparts 130ft high, and its cisterns hold a year's worth of water. Below it are the ruins of Sans-Souci, Christophe's palace, an extravagant fusion of European styles.

French military historians visiting the Citadelle recently were stunned by its sophistication, says Monique Rocourt-Martinez, of Haitian heritage group Ispan; but, more importantly, the hilltop colossus represents "the greatest monument to black freedom in the Americas". The Citadelle and Sans-Souci are, for now, at least secure and under restoration: recognising them as "a universal symbol of liberty", Unesco declared the area a World Heritage Site in 1978. "The question of national heritage is of utmost importance," says Rocourt-Martinez. "There is an urgent need for the people of Haiti to consult their heritage and traditions, if it is to reverse course and finally become a nation. A country that loses control of its history loses control of the future."

Bridging the gap between Haiti's inspirational history and its desperate present has always been a challenge. Getting anything done seems to be a challenge. But one reconstruction project gives reason for hope: the Iron Market in Port-au-Prince, a handsome 19th-century structure that was one of Haiti's best-loved buildings; its image appears on the country's bank notes. A year ago, it was a twisted, rusted relic. Half of it had burned down in 2008, then the earthquake damaged what was left. It has now been fully restored, and was officially reopened yesterday by Bill Clinton.

The Iron Market was designed and made in Paris around the same time as the Eiffel Tower, and there's a similarly heroic aesthetic to its riveted plates and expressive structure, augmented with neoclassical flourishes. Consisting of two symmetrical halls linked by a pavilion, it was originally bound for Cairo, hence the Islamic-looking minarets, but it somehow found its way to Haiti, where it was assembled like a giant Ikea flatpack in 1891. Today, freshly painted in red and green, the Iron Market stands out a mile, literally – surrounded as it is by the ruins of what used to be downtown Port-au-Prince. Its resurrection doesn't just bring back a piece of heritage architecture, it also reinstates a vital commercial resource that will hopefully anchor downtown regeneration.

"I've never been involved in a project with such drive and determination," says Scottish architect John McAslan, who was appointed to restore and rebuild the market. "There's been a genuine sense of urgency." McAslan became involved with Haiti two years ago, following his firm's voluntary work in Malawi with the Clinton Global Initiative (CGI), the former US president's foundation.

Since the quake, McAslan has taken a wider role in the country's reconstruction. His firm is co-ordinating the only government-approved programme for permanent housing, again with the CGI and other partners. This month, an exhibition will be held showcasing competition entries for a scheme to build, by May, 140 homes and a community centre. Designs had to be locally appropriate: affordable, easy to build (with local resources), fostering community values and utilising solar power and rainwater collection. Some 500 entries were received, including a healthy proportion from Haitian architects.

McAslan has also campaigned for the conservation of Haiti's historic architecture, starting with the Iron Market. "It symbolised so much to me," he says. "It symbolised the struggle of Haiti, its working life, its extraordinary history. Of course, rebuilding hospitals and schools and homes is a priority, but the country needs symbols of hope."

Rebuilding it to its former state was impossible, explains McAslan, but enough ironwork was salvaged from the burned-down north hall to restore the relatively intact south hall. This entailed the laborious straightening and reconditioning of thousands of pieces of iron, all done by hand at the workshop of a local artist. A new north hall was then built from scratch with US steel. Although this new wing lacks the delicate detailing of its 19th-century counterpart, inside it achieves the same light, spacious quality. Such a pragmatic approach underlines the project's urgency, while the half-old, half-new composition feels somehow apt: the shape, one hopes, of things to come.

For the last year, the market's traders have been selling everything from vegetables to stereos to unlabelled pills from makeshift stalls on the filthy streets outside the site, while, on the other side of the hoarding, work raced on. I stood among them as they patiently queued from dawn to register for the new stalls. The atmosphere was almost buoyant. For the first time in a long while, there was something to look forward to.