As part of the research work carried out by the Working Group 3 of COST Action FP0702, the need for vibrational comfort design for buildings and current regulations for comfort assessment of structural vibrations of timber floors in Europe have been summarised. Also the design practices of timber floors with respect to vibrational serviceability criteria, including those for fundamental frequency, unit point load deflection and unit impulse velocity, in up to thirteen European countries have been gathered and their differences been further assessed by analysing flooring systems constructed with three types of joists, i.e. solid timber joists, engineered I-joists and metal web joists. The unit point load deflection criterion is the most crucial one for structural design of timber floors with various types of joists and usually dominates the whole design. Finland tends to be the strictest, followed by Italy, the Netherlands, Austria and Norway, while Denmark, the UK and Ireland are the most generous. Even though EN 1995-1-1 has given general criteria for vibrational serviceability design of timber floors, the variations in the design equations and design limits are still large in the European countries, and hence further harmonisation is still needed.