Identifying design variations that strike the balance between environmental, energy and cost can be aided using multi-objective optimization. From the resulting Pareto-solutions, selecting a single optimal solution remains a challenge. Thus, research is still needed to increase the practical use of optimization for architectural, engineering and construction (AEC) practitioners. This paper presents the use of an optimization approach where the results and an environmental assessment are discussed with AEC practitioners. The method was tested in two case studies: a prestige tourist cottage and a multifamily residential building. Different superstructures, insulation materials and windows were varied for the cottage’s envelope whilst evaluating life-cycle energy and cost. In addition, the environmental impact in terms of CO2 emissions was evaluated for the initial and optimal design suggestions for the two different superstructures. For the residential building, the insulation material thickness and the windows were varied for its evaluation of life-cycle energy and cost. For the cottage, a report was written and then read by the practitioners and used as a base for future decisions. For the residential building, the results were presented orally for the practitioners. In both cases, it was possible to communicate the overarching results of the optimizations through visual plots, although future research should find ways to also explain the detailed results.