It's been three days since Vito Acconci and Ai Weiwei first met and the two architectural designers are busy swapping notes on what they have in common. Both are forward-looking in their approach and believe rules are meant to be broken. They also advocate knowledge should be free for all and art is not a subject but a way of life. But perhaps the least apparent similarity the two men have is that their fathers continue to inspire the way they think and work. Ai Qing, one of the most revered modern Chinese poets, fell foul of the anti-rightist campaign in the late 1950s and was exiled to farms, first in Manchuria and then Xinjiang, by the communist authorities. For decades his works were banned or burned. 'He did his public service, which was to clean public toilets,' his son, Ai, 53, says. 'He did it so well that ... it really touches me, because when everybody, the whole society, thought of it as a punishment, [my father] took it [as a duty]. 'He was a person who could find joy through his work and that leaves a very strong impression on me.' Similarly, Acconci was impressed and influenced by his father, who left Italy for the US at the age of 11. 'I grew up in a family that was very poor, although I was never made to know that because I grew up like an Italian prince,' the 70-year-old says. 'The most important things to my father - [who] possibly went to one year of high school - were literature, music, art not as culture to be studied but as something that was part of his life. 'My father lived in a world of puns, which was an amazingly invigorating thing. You grow up as a child thinking that language is this definite thing but it can be the opposite. Language is like in Marx Brothers movies; it's about things falling apart.' Acconci, a poet turned artist turned designer from New York and an important figure in 20th-century art, practises through his Acconci Studio, while Ai, who founded his studio Fake Design in 1999, is making news with his criticisms of the mainland government. Both were in town more than a week ago to work on a project for Para/Site Art Space that sets out to engage 'two artists with parallel trajectories, having both started from an interest in performance, and moved later on to architecture'. The show is likely to illustrate the many similarities of their approaches despite their different backgrounds. Ai points out that some of his works look 'almost identical' to those of Acconci in that they look at how objects affect people's lives and how they question our daily experiences. Acconci says he is interested in the idea behind the 'Bird's Nest', the Beijing Olympic stadium that Ai co-designed. He says the structure is a hybrid of modern technology and primitive animal instincts. 'We are both convinced that we have to work with the computer but at the same time think the same way animals think, and maybe there is something strangely similar in the principles of animal building and the principles of what's totally the opposite, the computer.' Both men are also known to never shy away from challenging boundaries and traditions. Acconci, who has a master's degree in literature and poetry from the University of Iowa, was until 1968 producing written works. He says the paper space of the page was important to him: 'When I started a poem, how do I move from left margin to right margin, how do I move from the top of the page to the bottom of the page? I realised if I was so interested in movement, why was I limiting this movement to an 8.5-inch by 11-inch piece of paper? 'So the context changed. It was no longer a writing context but an art context. It was 1968, a time of demonstration against the Vietnam war, a time of the toppling of any kind of authority figure - whether that authority figure was the United States, whether it was the male, whether it was the ... art gallery or the museum. For many people in my generation, we had a big question: why did museums have few windows or no windows? Is art as fragile as all that? Does art have to be so preserved from the rest of the world? The impression is that it probably does and that was something that I suspected bothers not just me but Ai.' And it is in this context that Acconci, in 1972, performed his most infamous piece, Seedbed, at the Sonnabend Gallery in New York. He installed a sloping floor before lying underneath it and performed a marathon of self stimulation, with visitors walking above, fuelling his sexual fantasies. He says his performance art was not a protest against the system, but just 'trying to live up to the time' when the common language was finding oneself or one's soul. 'But I don't believe in [the] soul. It's not that I don't like abstractions, I don't like abstract words. I want words as specific as possible. An abstraction is telling somebody what to believe. If you work in concrete words ... you are giving people a chance to think for themselves.' Freedom - and its protection - is a big issue for both artists. Ai recently said he felt a sense of duty to 'speak for the generation, or generations, who didn't have a chance to speak out'. He flew to Chengdu last year trying to testify for a campaigner investigating the deaths of children in the Sichuan quake and was beaten by the police. He suffered a cerebral haemorrhage. 'We are still talking about personal freedom, the very essential [right] for anybody who comes to this world, to have the basic dignity of life,' says Ai, the father of a year-old boy. 'You have the right to ... select your own knowledge and expression. Through that you are offering possibilities for others. So it becomes possible for a society to make adjustments. Under a dictatorship ... those conditions are not possible. It diminishes most people's very essential quality of life. 'As an artist, I have to do it because otherwise I cannot function ... I become a voice, not necessarily because I like to become that voice, [but] it's the real nature of my profession to search for the basic truth.' Acconci says that other than big cities such as New York, the rest of America 'is not so much about freedom ... but [being] overtly religious and let's keep to rules'. He says the impetus to do art is similar to that of doing science, that there is always another way. 'Is that other way necessarily a better way? At least it has to be tried out. Until you try it out you don't really know what way it is. I feel very close to what Ai Weiwei was saying. No, I don't want to be the people's voice, I want the people to have a chance to speak or to think.' Para/Site's executive director and curator Alvaro Rodriguez Fominaya says the idea behind next month's project is that it will be all object-based and 'a work in progress and will change over time'. The show is about taking risks, 'that is what makes it exciting. If art was to be a safe bet I wouldn't be here.' Both Acconci and Ai agree that projects shouldn't be complete. 'Maybe the only way other people can come in is if there is a loose end,' Acconci says. 'If a project is too complete, maybe other people are left out.' Acconci and Ai's collaboration will be shown at the Para/Site Art Space independent gallery in Sheung Wan from May 7 to July 4.