This paper presents a study of the factors that influence array layout on wave energy farms. The WEC considered is a two-body heave converter extracted from Babarit et al. (2012). Simulations were run through a time domain model from de Andres et al. (2013) with irregular waves considering different sea states. Factors analyzed in this paper are array layout, WEC separation, number of WECs and wave directionality. Results show that wave directionality is very important in order to achieve constructive interference. When looking at the number of WECs the conclusion is that as the larger the number of WECs, more interactions are possible and therefore, the higher the interaction factor is. Regarding array layout, triangle and square configurations were found to be similar and the efficiency of each one depends on the most probable peak period. Separating distance was found to be a key factor and was set as the optimal one. Finally, wave climate was classified in different subtypes around the globe. The optimum layout in these sites was assessed. The influence of directionality was studied and the triangular configuration was found to be the most favorable for multidirectional climates while square configurations were most adequate in unidirectional climates.