Energy Efficiency (EE) in construction sector is nowadays the best chance to boost green economy in Europe, generating new business opportunities that will foster high quality employment creation helping to recover a strategic sector ruined by crisis.There is a fundamental barrier that is preventing this from happening: SMEs presence in the construction sector is remarkable with a fundamental impact on sector’s performance. Continuous progress in technologies and solutions to improve energy efficiency in buildings do not reach companies in order to implement them. For this, the current main problem must be solved: Knowledge Transfer isn’t flowing effectively among agents in the value chain of the EE market (particularly SMEs), thus knowledge sharing is needed to overcome technological and economic barriers.ee-WiSE aims to develop an EE Knowledge Transfer Framework (KTF) in building retrofitting with especial attention to SMEs, applied to a specific geographic area, the Mediterranean.ee-WiSE will be focused on the Mediterranean because its particular weather conditions require EE to be analyzed by considering specific and not generic solutions. In addition, the Mediterranean economies had based much of its economic growth in a very traditional building sector which tremendously affected by the real estate bubble burst.Similarly, the project focuses on retrofitting rather than new building for the greatest potential of EE measures in existing buildings, the high incidence in CO2 emissions of the buildings stock and the large number of SMEs participating in this activity in construction sector.Throughout its WP of conceptualization and definitions, information and best practices gathering and analyzing, design of the KTF and its tools, and finally its validation, EE-wise will provide an useful methodology to imagine, design and validate EE enhancement measures in the Mediterranean environment to develope EE market and related business.