The PC software AMCE is proposing building actors (owner, project authors$\dots$) a Multiple Criteria Decision Aid procedure (MCDA) to optimise the building envelope about cost and energy performances, during the sketch design.

Two main modules are linked, where the user interactively goes:

– the first one manages parameters describing the project requirements;

– the graphic pen-based module allows to draw the sketch; it calculates geometric parameter values and put them back in the first module.

Permanently informed on forseeable performances, the user can any time search for optimal scenario giving best satisfaction (monoactor optimisation) or most preferred compromise (muliactors optimisation).