Those people who have tried the live local challenge know that it's not easy to have a community-first philosophy informing every decision for a week. But what about doing it for a year, with a set of very strict rules?

Colin Beavan, aka No Impact Man, did just that, and the eponymous documentary about his project had its Australian premiere at the Sydney Film Festival last weekend.

It would have been easy for No Impact Man to be a righteous, preachy and/or pedantic film about all the stuff we're doing wrong. But the filmmakers instead tell a much deeper story, focusing on the effect Beavan's project has on his family (his wife, Michelle Conlin, and young daughter Isabella are semi-willing participants in the experiment), and confronting the difficulty of taking a stance that can veer into righteousness, preachiness and pedantry.

Beavan aims to live emissions- and non-biodegradable-waste-free for a year in New York City, and this involves food only from within a 250-mile radius, no packaging that can't be recycled, and several more shocking rules, including shutting off their apartment's electricity for the latter six months of the project.

The film is at times inspiring, in large part because Beavan is mostly indefatigable about both the feasibility of his project and his belief that one person can inspire change in others. His winsomeness when discussing the discontinuation of toilet paper use (!) or being able to return berry containers to the farmers' market is impressive, although the film also captures his wife's exasperation. Winsomeness can only get you so far.

There are low points, too. An improvised fridge fails and milk curdles. Comments critical of project appear on articles about Beavan and his family, and deflate him, temporarily. And as noted, family life isn't always sitcom bliss, and the pressure the project puts on Beavan and Conlin's relationship is part of what makes the film so watchable.

Highly worth a bike ride to the theatre, and Beavan's site is worth repeat visits too, both for his posts and for a good selection of links to news and other blogs.