The objective of this final project work was to make an interior design plan to a coffee house. The plan was focused on customers´ area. The objective was to make the coffee house more comfortable with new lightning and material choises. The practicality and customers´ needs were to be improved with the positioning of furniture and a play corner for children. The project was based on using Art Nouveau style. Art Nouveau style was approached by reading literature. At the same time the history of the building and its residents was discovered. A survey research and picture questioning were made to help the project. The research was made to discover people´s opinions about interior colouring and the behaviour of coffee house customers. The objective was also to find out on what basis people choose the coffee house they visit and how outer factors like lightning effect this matter. The survey research was also made to discover how people choose their place in coffee house. Literature about the effects of lightning and colours in interior planning was also discovered. This informatoan and results were used to make presentation pictures using Archi CAD.