The LearnEER project will develop an innovative mutual learning platform to increase professionals skills and capabilities towards the Energy Efficient Retrofitting (EER) of buildings. EER competences and skills required in new employment opportunities are relatively new and not included in curricula from the last 30 years. That explains the lack of capacities among professionals related to this issue. To train EER workforce, the Mutual Learning approach is identified as a wise solution to develop a more flexible and open environment for accessing to this training needs. This way, the LearnEER platform is applied as a training practice in which learners interact with other learners to share and validate knowledge, thus facilitating new opportunities on the labour market.