In urban areas, road traffrc noise is a dominant source of environmental noise and a major cause of noise annoyance and disturbed sleep. It has been hypothesized that respondents highly exposed to noise at multiple sides of their dwelling, may be expected to be worse off than respondents with the same exposure at the most exposed side, but also having a quiet side to their dwelling. Previous studies provide support for this hypothesis, however to date only a limited number of studies have investigated this hypothesis. There is a need for strengthening existing evidence, and for further quantification of the effects. Within the EU project QSIDE, the effect of the least exposed facade on annoyance and sleep response is studied in different EU cities in Sweden, Belgium and the Netherlands, including Gothenburg, Stockholm, Antwerp, Gent and Amsterdam. In this paper we discuss the general picture arising from the outcome of these studies. We discuss what the implications may be for new situations (urban planning) and existing high exposure situations (noise abatement measures). The noise environment may be improved by taking into account the exposure levels, and promoting quietness, at the least exposed façade.