Innovations for a more efficient rehabilitation

According to the Passivhaus Institute in Germany, buildings classified as passivhaus can reduce their energy consumption for heating and cooling by up to 90% compared to existing buildings, and by 75% compared to new construction buildings.

The rehabilitation of buildings is a key factor in increasing energy savings and sustainability in the construction sector of construction. To ensure a high level of efficiency and quality in the rehabilitation process, it is advisable to previously define a series of phases to plan the execution of a rehabilitation project.

Phases in the execution of an efficient rehabilitation

In a first phase , the elements that most influence the energy demand of the building must be renewed, especially regarding consumption in heating and cooling. For this, renewable energies will be added for the production of heating, cooling, hot water, and electricity. It is advisable to use condensing boilers for the production of hot water (ACS). Other types of renewable energies can also be installed, such as geothermal energy, cogeneration systems, or hybrid systems that include one that uses conventional energy along with one that uses renewable sources. Subsequently, in a second phase, the exterior carpentry should be replaced with ones that have a high level of thermal and acoustic insulation, as this is the area of the facade where the most energy loss occurs.

In a third phase, conventional construction materials can be replaced with those that have photovoltaic properties. In this way, every element that is part of the facade becomes a source of energy production for the building's consumption. The photovoltaic facade represents a significant advance in the self-sufficiency of a building with clean and renewable energy. It is installed on the exterior of the vertical enclosures and basically consists of a layer of thermal-acoustic insulation where the sub-structure that supports the finishing material is anchored. Between this and the insulating material, an air chamber is created that in summer works with a chimney effect, displacing air towards the top and thus eliminating heat and humidity. In winter, this same process allows hot air to be supplied to the heating system and for the production of ACS.

The incorporation of an air chamber between the finishing material and the interior enclosure of the facade also helps to improve the thermal performance of the building. By increasing the thermal inertia of the exterior envelope, heat losses in winter through the enclosure are reduced, thus facilitating significant energy savings.

During this phase, skylights or photovoltaic curtain walls can also be incorporated into the construction systems. The semi-transparent photovoltaic glass of amorphous silicon technology is capable of simultaneously producing electricity and allowing natural light into interior spaces. It acts as a filter against infrared radiation, preventing overheating of buildings, while also reducing ultraviolet radiation by up to 1%.