The Victorian government is slashing stamp duty for new apartments, units and townhouses as it tries to give the state's housing market a boost.

Premier Jacinta Allan on Monday announced a 12-month stamp duty concession for anyone buying an apartment, unit or townhouse when they buy off-the-plan.

The concession allows all construction costs to be deducted from the sale price when calculating stamp duty.

Previously, a concession was offered to first home buyers and owner-occupiers, but was capped as the reduced value of properties had to be under $750,000 for first home buyers and $550,000 for owner-occupiers.

The cap has been removed so the concession will apply to dwellings of any value and any buyer can access the discount.

The government estimates the concession will mean someone buying an apartment off-the-plan is likely to pay around a quarter of the stamp duty they would have paid otherwise.

The new concession does not apply to house and land packages or other dwellings without strata subdivisions, and first home buyers and owner occupiers can continue to access the other existing concessions when purchasing those properties.