(1)  A person –

(a) who has undertaken to carry out building work or construction work under a building or construction contract; or

(b) who has undertaken to supply building or construction-related goods and services under a building or construction contract –

is entitled, on and from each reference date, to a progress payment.

(2)  The amount of the progress payment is to be the amount calculated in accordance with the terms of the contract.

(3)  However, if the contract does not expressly provide for the calculation of the amount of the progress payment, the amount of the progress payment is to be –

(a) the amount calculated on the basis of the value of the building work or construction work –

(i) carried out before the reference date by the person under the contract; or

(ii) undertaken to be carried out before the reference date by the person under the contract; or

(b) the amount calculated on the basis of the value of the building or construction-related goods and services –

(i) supplied by the person under the contract before the reference date; or

(ii) undertaken to be supplied by the person under the contract before the reference date.