One of the existing tools that could help creating smart energy policies is the Energy Performance Certification (EPC) of residential buildings, by introducing energy efficiency as a comparative criterion for real-estate purchase choices, influencing real-estate market value, stimulating energy saving investments, moving the housing market towards greater energy efficiency and creating comprehensive databases which are fundamental for shaping smart strategies on urban / regional / national levels. But EPCs in their actual form, calculated with a standardized approach which purposefully (and understandably) gets human factor out of the equations, do not allow appropriation of the results by potential buyers or tenants: often distant from reality, overestimating consumption, they usually result in a general misunderstanding and misuse of the document. This thesis therefore focuses on the integration of the human factor in the Walloon energy performance calculation methods, to develop complementary “custom-made” certification, advice, recommendations and help in renovation strategies decisions.