Premiums for liability insurance have risen by up to 800%, crippling the industry and forcing some contractors to trade illegally.
The crisis has been caused by collapse of Independent Insurance and the decision of some syndicates to pull out of the market in the wake of the terrorist attack of 11 September 2001.
The NASC said the insurance scheme, which is only available to members in the southern division, was a promising sign, as it recognised that contractors that were members of the organisation did take health and safety requirements seriously.
In a statement it said: "Insurers are now recognising that NASC membership demonstrates a high standard of health and safety, resulting in members being able to secure lower premiums than non-members."
The confederation's northern and north Wales region is also in discussion with Leeds insurance broker Contractsure with a view to developing a similar scheme.
The deal is the latest in a trend for trade bodies to set up schemes for their members.
Last month the National Federation of Builders set up a scheme for members with broker Zurich.