The environmental assessment system Miljöbyggnad is a Swedish system initiated by Bygga-Bo-Dialogen to assess buildings with regards to three main areas; “Energy”, “Indoor climate” and “Materials”. A building can obtain three different classifications depending on how well it manages to meet the demands. GOLD is the highest classification and is followed by SILVER and BRONZE. The majority of the measures needed to comply with the demands are done during the design phase. During the production phase a considerable amount of work is required to make sure to document the built in products and make sure they do not contain any dangerous substances. The thesis is based on the experiences retrieved by working with Miljöbyggnad in Skanska’s project Sickla Udde skola which is aiming for the highest classification GOLD. Interviews have been conducted with employees of Skanska working with the system in order to take part of their experiences. The thesis identifies difficulties linked to working with the main area “Materials” during the production phase. It also describes the available product data bases used to simplify the work with the system. Furthermore the thesis gives suggestions on how to work with Miljöbyggnad during the production phase.