Tens of thousands of first home buyers will no longer have to pay stamp duty on properties worth up to $600,000 under an Andrews government plan to make housing more affordable.

Long-awaited reforms to be unveiled on Sunday will give new home owners savings of up to $15,000 by exempting them from stamp duty on new and existing properties, in a bid to help more Victorians to break into the expensive housing market.

A $50 million pilot program will also give about 400 people the chance to co-purchase a dwelling with the government, which will offer to take an equity share of up to 25 per cent for each property – in turn reducing the deposit that a first home buyer would otherwise pay.

The so-called "HomesVic" program will begin in January next year, targeting couples earning up to $95,000 and singles earning up to $75,000. Buyers will need a 5 per cent deposit to be eligible, and when the property is sold, the government will recover its share of the equity.