Renovation, retrofitting and improvement of existing buildings, provide the opportunity to upgrade the energy efficiency of the commercial assets of the building without affecting their smooth operation. Renovations often involve modifications to existing commercial buildings and residences that significantly improve their energy efficiency and reduce their energy demand. Also, the reconstructions and transformations of central networks in a building are an opportunity for its energy upgrade. Renovations significantly improve energy class and operating costs, especially in large buildings and are preferred by tenants because they are a strong incentive for their businesses to gain added value in the market.