In early eco-innovation phases, design teams need to assess the environmental relevance of ideas, and consequently, the evaluation stage becomes even more critical, subjective and uncertain than in traditional design. This paper tackles the following question "How to turn elementary ideas into concepts with a high environmental potential in a design team?" Based on eco-innovation literature, we propose to test two methods involving mapping, selection, combination and environmental evaluation of ideas (namely Combineval and Geneval) plus additional free method. Starting with 14 to 15 elementary ideas, three groups of mixed academics and industrials are asked to generate 3 to 5 environmentally relevant concepts on two different test cases. Main results show that there is a large inter-group variability in the evaluation of environmental potential of ideas. Our contribution deals with the systematisation of the environmental evaluation of ideas in early phases thanks to adapted methods and tools. Should the format of ideas be highlighting environmental or a sustainable consideration is one of the emerging issues of the paper.