Sauna N is a yard sauna designed for a private client in Helsinki, Finland. The building consists of a living room, small kitchen, sleeping loft, sauna with washing facilities, and a covered terrace. Functionality, authentic materials, and interesting details were fundamental ideas in the design as well as the wish of the client. It was also essential to take into consideration the new building’s relationship with its surroundings and a possibility for later extension. The massive timber building has a simple basic form, encasing an undulating exterior wall through which the interiors open towards the terrace and the yard. The sleeping loft and partitioning wall elements were made from CLT. Natural materials have been used in the details and finishes in a rich, atmospheric, and elegant way.