This paper describes the first stage of an approach developed through the NERC/Defra EBAO (Optimising Array Form for Energy Extraction and Environmental Benefit) project to model the potential environmental impacts of a range of wave farm designs. The eventual aim of the methodology is to inform array design in order to minimise negative environmental impacts or even produce benefits. The modelling study considers differing array sizes and layouts, allowing issues such as the most appropriate device spacing, or the need for a ‘corridor’ between clusters of devices, to be assessed from an environmental perspective. The results presented in this paper focus on the physic al wave climate, using the EMEC test site as a case study. The modelling uses the SWAN spectral wave model to assess the potential far-field change in the wave climate due to different array layouts and spacing. Preliminary results indicate that although designing arrays as sub-array clusters with corridors between them will have a notable effect on the wave climate impact in the immediate wake of the array, at far-field distances (>5km), differences in the impacts when compared with regularly-spaced arrays are negligible. These results are discussed in the context of other physical impacts including acoustic noise, and conclusions drawn regarding the overall impact of array design on the marine environment.