The current energy model, both nationally and globally, is going through an important transition due to an imminent need to preserve our planet in terms of sustainability, since high levels of consumption and contaminant emissions frame this current model as unsustainable, and in many cases, dependant. This transition, mainly based on the implementation of renewable energy and energy efficiency in order to reduce the fossil fuel consumption, requires at the same rate, fast development and technical solutions, as well as a strong political and business contribution. This project is developed within this transition framework, contributing by implementing renewable energies and other energy efficiency measures in the rehabilitation of DHW and heating facilities of a nursing home, with the clear objective of reducing the current natural gas consumption, and so reduce the CO2 emissions associated to this as well, without affecting the consumption profile of the nursing home. This implementation is fulfilled with an economic viability analysis.