The paper focuses on ethical aspects related to the transfer of development rights (TDR), that is on the ethical values on which the choice to implement a TDR programme rests/should rest. In particular, the paper stresses the importance of taking the principle of equality of all citizens before the law into serious consideration, and analyses its implications for the design of a TDR programme. Three questions in particular are taken into consideration: firstly, the relation between the concept of equity and the concept of equality (i.e., equal treatment); secondly, the different equality potential inherent in different versions of TDR programmes; thirdly, the use of equality principle as a guiding ideal for designing a TDR programme