The goal of this communication is to present the first ideas and proposition about the panels layout design problem in order to improve building energetic performances. First the origins and interest of the problem are presented. In two words, too many buildings with poor energetic performances and too low ratio of replacement lead to a very strong energetic retrofit need. Consequently, we describe the panels layout design problem, discuss some related works and propose the very first ideas in order to solve it with a heuristic approach. An example illustrates the problems and the propositions.