Catchwords:

BUILDING AND CONSTRUCTION – contract – damages – defects – whether the contractor was responsible for defects in materials supplied by a third party – where the relevant contractual warranty was confined to “works required to be performed by the contractor”

BUILDING AND CONSTRUCTION – contract – termination – quantum meruit – whether the contract operated to generate release and waiver of subsequent claims for payment by the contractor – where the contractor had suffered irreversible detriment by incurring liability to pay for materials prior to the principal’s insistence upon strict adherence to the contract

BUILDING AND CONSTRUCTION – contract – variation – implied promise to pay – whether the works constituted “variations” as defined in the contract – where the principal requested that the contractor supply materials that it had originally insisted upon supplying itself – where written approval was sought by the contractor in respect of all other variation works

CONTRACTS – breach of contract – consequences of breach – right to damages – estoppel – promissory estoppel – whether it was unconscionable for the principal to resist payment for the performance of certain works – where the principal was positively encouraging the contractor to complete outstanding works – where such encouragement followed the principal’s purported departure from the assumption that it had approved these works

EQUITY – estoppel – promissory estoppel – general principles and maxims – equity will not permit detriment to be visited upon or remain with the party who has not been sufficiently clearly disabused of the counter-party’s intended departure from the relevant assumption inducing reliance

ESTOPPEL – promissory estoppel – detrimental reliance – whether the principal discharged its duty to inform the contractor labouring under an assumption that the basis for that assumption had “materially changed” – where such material change must be communicated in sufficiently clear terms – where the relevant communication did not expressly refer to or address the topic of the assumption – where the principal was positively encouraging the contractor to complete outstanding works in respect of materials that the principal knew it had originally undertaken to supply itself