Transformation into dwellings, an acoustical problem?

In the Netherlands there is a need for dwellings especially for starters because that type of dwellings were not built during the last years. Also because of the crisis many office buildings, old factories, old service flats etc. are not in use now, waiting for a new destination. In many cases transformation into dwellings is a good solution for all. The praxis for this transformations gives birth to new acoustic solutions for a good sound insulation between dwellings and low sound levels for installation noise. Special problems occur in offices in the direct neighbourhood of traffic high ways. Special constructions are needed to lower the sound level on the façades.A few examples will be given to show the solutions and the restrictions for an old school, an old factory with a steel construction and a young office. The assumptions were treated: Not the legally obtained level ( it is not allowed to make it worse) but a good acoustic dwelling with a sound insulation level as high as the newly built level (LnT;A not higher than 54 dB and RA = 53 dB) or as high as possible or even better.