Two decades ago, unjust enrichment was described as “the Cinderella of law, barely 10 years old but growing up rapidly. Until recently unrecognised and overshadowed by the ugly sisters, Contract and Tort, Cinderella’s day has arrived.” In England a claim for unjust enrichment was initially referred to as a claim in ‘quasi contract’. This language has now been abandoned and unjust enrichment has a strong foothold in the landscape of commercial law and its role and limits are becoming more clearly defined. Despite this, it is only infrequently pleaded in construction cases and when argued it is often set out in broad terms where the facts do not support such a claim. However, this is cause of action that should not be overlooked by a contractor or employer – especially if they have claims that fall outside the four corners of their construction contract.