This thesis critically examines what is often described as ‘betterment’ when damages are sought for repair or replacement cost in tort and contract claims involving damage or destruction to property. The predicament as to when betterment should or should not be accounted for when assessing the plaintiff’s damages remains a contentious issue. In addition to the betterment predicament, the court needs to address a number of other important issues in disputes concerning betterment, including the following: how betterment should be identified and defined; how betterment should be appropriately valued in monetary terms; and how evidential and proof-related matters concerning betterment should be dealt with and allocated between parties to the action. The legal principles to be applied to these matters are in need of clarification. In relation to the betterment predicament this thesis argues and proposes for a general approach to account for betterment, subject to reasoned exceptions. This approach will ensure more just and reasoned outcomes in the assessment of damages for damage or destruction to property. This thesis provides an in-depth analysis and evaluation of the law relating to betterment and proposals for changes and reform, in an area of law where currently there is a lack of comprehensive scholarly attention. By contributing to a theoretical and practical understanding of the law relating to betterment this thesis will benefit the general legal community. It will also, in particular, benefit and assist litigating parties and counsel faced with betterment disputes, as they will generally be in a better position to address and resolves these disputes more effectively and expeditiously.