In Finland during the last few decades, mineral industrial residues (by-products) have been used in earthworks, but only to a limited extent relative to their total volume. The most important barrier to efficient recycling of by-products has been the need for a site-specific environmental permit, since the permit process tends to be time-consuming and laborious. In 2000 a working group was set up to prepare national legislation, i.e., a Government decree, in order to promote the use of by-products in earth construction. The aim was to exempt certain residues from the environmental permit obligation. At the first stage, the working group determined specific decision criteria for the selection of the by-products to be included. For the selected residues, the acceptable construction applications and material-specific environmental standards were defined. Various difficulties were encountered during the preparation of the decree. These were mainly caused by the lack of data and by some ongoing changes in environmental regulations. Furthermore, the draft decree received several critical and partly contradictory comments and proposals for amendments. This resulted in considerable delay in implementation.