Social housing dating from the postwar years through the end of the twentieth century
is one of the major stores of European cities’ residential stock. As it is generally characterised by
a poor thermal performance and an ine cient control of energy consumption, it constitutes one
of the main targets for residential heritage renewal. This study aimed to locate and quantify air
leaks across building envelopes in Mediterranean multifamily housing with a view to curbing the
uncontrolled inflow of outdoor air that has a direct impact on occupant comfort and housing energy
demand. Airtightness tests conducted in a series of protocols to quantify draught across envelope
elements were supplemented with qualitative infrared thermographic and smoke tests to locate
leakage pathways. Air was found to flow mainly across façade enclosures, primarily around openings,
as well as through service penetrations in walls between flats and communal areas accommodating
electrical and telecommunication wires and water supply, domestic hot water (DHW), and drainage
pipes. The general absence of evidence of draught across structural floors or inter-flat partitions was
consistent with the construction systems in place
