The Zentrum Paul Klee museum is dedicated to the life and works of artist Paul Klee (1879 - 1940). The museum is situated in Bern and features approximately 40 percent of Klee's entire pictorial works. The majority of Klee's works were donated by Livia Klee-Meyer, his daughter-in-law. Livia inherited nearly 690 of Klee's works. She then donated them to the city of Bern in the summer of 1997. Livia's donation topped with additional works and documents loaned by the Paul Kleeson Foundation and his family produced 200 more items from the artist. To accommodate the large collection and make way for a cultural centre for Bern, the decision to build a museum on the eastern outskirts of the city was made. Famous Italian architect Renzo Piano was contacted in 1998 to design the new facility. A preliminary project was elaborated in 200 and the building was finally completed in 2005. On June 20th, 2005, the Zentrum Paul Klee opened its doors and welcomed visitors for the first time. Personally, Klee was not only an artist, but a musician, poet, and teacher as well. He is now known as one of the 20th Century's most significant and compelling artists. Klee spent a majority of his years in Bern. Today the Zentrum Paul Klee serves as a Bern hallmark and boasts a unique exterior that features three undulations blending into the landscape. The Alps serve as the museum's background and it actually looks like three artificial hills. The first of these three hills houses a multi-functional room, auditorium and children's museum. The second hill is home to the exhibition section containing Klee's work. The third and final hill is reserved for management and research activities. Each hill, or wave as some have come to call them, are connected by a covered passageway. The roof of the museum is covered using Ugitop, a matte finished stainless steel product. The roof is .4 millimeters thick having been molded in the mill before its installation on a wooden structure. Intentionally visible from both the inside and the outside, the structure is formed by a series of parallel steel arches. The pieces of the arches were produced by CNC equipment and had to be manually welded. The use of steel was deemed necessary because it was the only material found to respond adequately to the need for variations in the plate thickness and different stresses. Lastly, tall variations exist in the arches depending on the point of each case. Through the use of reinforced concrete support points, standing horizontal forces collaborate with the floor slabs. Additionally, two series of tie rods guarantee the cross-sectional stability of the arches. Unfortunately, a large portion of the museum's collection cannot be exhibited at this time. This is due to concerns of preservation. The works, however, are made available to researchers. To ensure preservation of Klee's art, the museum also refrains from the use of zenital light. Instead, light is illuminated from the west façade through which it is filtered by a system of translucent screens thus creating a gentler light.