SIMAIRrwc is a Web based evaluation tool for meeting the EU directive on air pollution limits in residential areas using wood combustion. The background is a four-year research program (2001-2004) called Biomass Combustion Health and Environment. Some conclusions from this program were that emissions from small scale wood combustion can influence human health mainly due to high emitting old wood stoves during cold weather conditions and that the air quality in such areas can improve significantly if old wood stoves were replaced by modern wood boilers attached to a storage tank or with a pellet boiler. SIMAIRrwc is based on the same principles as SIMAIRroad, which is a Web based evaluation tool for road traffic i.e. coupled model system using different models on local, urban and regional geographical scales, best available emission data, but at the same time presented in a very simplified way. In this project SIMAIRrwc has been applied in five different Swedish municipalities. The aim has been to apply and improve the model in cooperation with the municipalities. The conclusions from the project are: - Small scale wood combustions in residential areas are local problems which sometimes include only a few houses and/or wood-burners. - Air quality problems related to the EU directive are mainly due to particles. - Combinations of residential areas with wood combustion and emissions from nearby dense traffic roads might give rise to bad air quality. - Actions require knowledge about individual equipment which needs information from the local chimneysweeps. - The best way to identify problem areas is to use model calculations. - If model calculations indicate risks of exceeding air quality limits, then new calculations should be made with improved input data taking into account for example information of district heating or other installations that can effect the emissions. • Before actions are taken it may also be useful to make measurements. The measurement site can then be selected in the area where the model calculations show the larges impact. • SIMAIRrwc is a powerful tool that can be used for identification and visualisation of areas where there might be air quality problems due to residential wood combustion.