In the present paper, we apply bacterial memetic algorithms in the context of multi-objective optimization. The goal of the development is to optimize the energetic quality of residential building envelopes in a sustainable manner. Our interest is to determine a good compromise between the quality of the building envelope and the total cost of the installed energy saving components. We provide a description of the applied bacterial operators and the particular ordering of the population that is a non unique procedure. In order to refine the ordering we implement a variant of the distance metric for comparing the non-comparable individuals. The numerical computations are performed by the EnergOpt computational framework of the authors. The performance of the algorithm is demonstrated on the solution of a benchmark test case. Finally, the optimization of an existing building is presented to demonstrate the potential of the methodology. © 2013 IEEE.