you would need a 457 visa from what i understand (my missus is in HR), which is limited to skilled workers. you would have to prove that yor skillset is not available here locally.
currently the construction industry is slow in australia due to economic uncertainty. i work in the building services engineering field and there is not much going at the moment. my company has made 150 people redundant last week with another round of cuts rumoured for next month.
generally the construction industry is about 12-18 months behind the engineering industry. some people say things will pick up after the election this year (sept) but that is more just noobs that dont understand how the world works.
i'd like to think that in the next 12-18 months that things would pick up engineering wise, which would in turn boost the construction sector, but i'm not confident that it will.