What makes beautiful architecture? To begin with, this is the wrong question to ask, according to leading Hong Kong architect Rocco Yim Sen-kee. Calling a building beautiful immediately marks you as uninitiated. As he says, 'Of course, architecture is about aesthetics, but it's aesthetics built on many things. Is there good use of light, material and space? What does the building do to your state of mind? And can it unlock your imagination about a culture or a particular feeling?' The softly spoken architect is not pontificating: he is recalling the ideals of architecture learned at college three decades ago. Over the years, this intellectual foundation, coupled with Yim's talent, has given rise to some of Hong Kong's most prominent creations, including the Peninsula Hotel extension, the Park Lane Shopping Boulevard, Citibank Plaza and IFC2 (a collaboration with celebrated Argentinian architect Cesar Pelli). This year at least three of his projects will be completed in Hong Kong and on the mainland. Yim is known for his ability to weave modernism into densely populated urban spaces. Now in his 50s, he won an international competition late last year to build the 500 million yuan (HK$568 million) new Yunnan Provincial Museum, adding another accolade to his long list of achievements. It is 'entirely contemporary' in its construction, he says of the glass-clad building, the form of which alludes to Yunnan's natural landscape, in particular the famous Shilin 'rock forest' outside Kunming. Having built a solid portfolio of commercial buildings, Yim is preoccupied these days with public and cultural architecture, evidenced by the clutch of buildings he and his 110-strong company are working on. These include a teaching hotel at the Polytechnic University, which features glass atria designed to be integrated with the surroundings. There is also the much publicised 'Door' in Tamar, an arched complex that will become the Hong Kong government's new headquarters in 2011. Across the border in Guangdong, he is building a multipurpose cultural centre in Shenzhen and the Museum of Guangdong. The latter is in the shape of a Chinese treasure box and is his favourite project to date. Yim is not dodging commercialism - the redevelopment of the former Hyatt Hotel in Tsim Sha Tsui which he is close to completing is purely commercial, he says - but now, well into the 'third stage' of his career, he is trying to focus on non-commercial projects. 'When I first started in architecture it was a period of taking up small projects and joining design competitions. As the company grew, big commercial projects started rolling in,' he says. 'I think it all began with the Bamboo Pavilion [for the Hong Kong/Berlin Festival in 2000].' His new bond with public and cultural architecture has marked Yim's position in Hong Kong's architectural world, which provides most architects with few options beyond private property projects. Yet the change is also a return to the ideals that Yim embraced in his formative years. 'In the perfect situation, you don't worry about commercial constraints, artistic value is attached with great importance and the building serves not only a small group of people but the general public,' he says. 'Every architect wants to achieve that. That's a value we learned at college.' His career focus may have evolved, but Yim's passionate belief in the strong ties between architecture and city life has changed little. 'I always believe no building survives alone; it coexists with the city. Its worth is judged by how it interacts and forms a relationship with the surroundings.' This fundamental idea helped propel Yim to fame in his late 20s. In 1983, a few years after Yim had read architecture at the University of Hong Kong, the mainland was in talks with Britain about the future of colonial Hong Kong. The city's economy was in the doldrums and Yim had few jobs in hand. Being young and energetic, he looked abroad and entered the Opera Bastille design competition in Paris. He came up with a scheme that featured a street leading from the Bastille Plaza, allowing it to 'interact with the opera and enable all kinds of human activities to flourish'. Competing against 744 contestants from 50 countries, the inexperienced Yim did not expect to be named one of three first-prize winners. The judges commended his design for being a 'strongly marked architectural gesture' and for its 'lyrical vocation'. In the end, the work of Canadian co-winner Carlos Ott was adopted, but Yim's interaction-oriented approach lives on; the new Hong Kong government headquarters serves as a recent example. 'A lot of people think it's going to be an iconic piece of architecture,' he says of the Tamar project. 'But it's not - it's going to be an iconic place. We want it to refine the quality of Hong Kong's public space. The green lawns, green roof and the open space on the ground level will serve to connect with the surroundings.' As with many of his peers, Yim ventured across the border in the late 1990s. The mainland's constant thirst for new ideas has seen his projects multiply in recent years. 'Compared with Hong Kong, the mainland is more receptive to new ideas,' he says. 'The entrepreneurs are younger, in their 30s or 40s. They're more flexible, less conservative. They hire an architect for his creativity.' However, these projects are not without difficulties. For Yim, the biggest problem is the lack of sophistication of some mainland cities, which makes it difficult for his creations to do what he wants them to: interact. A case in point is the HK$400 million Guangdong Museum project, a lacquered box-like structure in Guangzhou with features such as alcoves and layered spaces. 'The site where the museum is located is bleak and empty. The whole area simply hasn't taken shape. We know [British-Iraqi architect] Zaha Hadid is building an opera house there and there's a river nearby, but that's it. There's no other reference point to guide or inspire us. We have to rely on the museum to shape the area.' Hong Kong has a different set of issues, Yim says: the crux of the problem being a lack of creativity. 'There's not enough initiative to encourage creativity. We have almost no public design competitions for new buildings, whereas on the mainland even a small community would try to get the best design through public competitions,' he says. 'This stagnancy is an inevitable part of development. Every city will gradually become more conservative after years of growth. Hong Kong is right at this stage. Just as we thought we still had an edge, we were taken aback by the Water Cube [National Aquatics Centre] and the Bird's Nest [National Stadium in Beijing]. All we have is the Hong Kong Stadium.' To move things forward, the government should start with the basics, says Yim. 'Run design competitions. It should take the lead in being the patron of local design - everything from logos, business cards of officials and public trash bins,' he says. 'It's a really big issue: Hong Kong needs to map out a new city blueprint for the 21st century.' So is there still reason to be optimistic about Hong Kong's architectural future? 'In the short term, I'm pessimistic,' he says. 'Our political system is not going to allow dramatic changes. And if I may put it boldly, our legislators don't know enough about architecture. 'But in the long run, I am optimistic. The concentration [of facilities and infrastructure] in Hong Kong gives us a very good foundation to make improvements. We have yet to wake up, but we will one day.'