Improving residential building efficiency with membranes over façades: The Mediterranean context

In the EU-28, only 3% of the residential building stock is rated “A” on energy efficiency (EPDB; and according to EU guidelines and targets to 2050, renovation shall achieve 80% and the replacement the other 20%, which represent a 90% cut in GHG emissions considering 1990s values. In 2016, EU-28 households accounted for 24.5% of the total (final) energy consumed: 79.2% for indoor and water heating (94.1% from petroleum derivatives), and 0.3% for cooling (100% electric sources). The latter indicator has a potential increase of up to 8.7%, based on households' electricity consumption in 2015, 785 tWh/a, considering Global Warming predictions and air-conditioning market growth, supported by technological improvements and consequent technological price-cutting, stable economic growth, and low-rate fares. The research proposes the application of tensile membranes backed by mineral panels to wrap residential buildings. It adds a semi-opaque ventilated façade solution to the external cavity wall, mimicking traditional membranes used to shade sun-exposed streets in Southern Europe. This architectonic solution intends the renovation of “energetically” dated and degraded urban areas by seeking new environments and integration with newer urbanizations. The goal of this approach is to increase the residential stock efficiency by reducing the energy expenditure, GHG emissions, and maintenance operations while improving comfort and building lifespan. The proposed solution presents reliable economic results, as assessed by the Profitability Indicator (Energy Savings minus Investment), over a 30-year span: favoring inland and continental coastal cities and improving average performance by 62.23%. From a strictly financial perspective, the performance of the solution is modest at the islands’ seaside.