Under 1900-talet har elektrisk belysning använts som en del i byggnaders utformning, med permanent fasadbelysning som en integrerad del i arkitekturen. När en ursprunglig fasadbelysning försvinner eller förändras, så försvinner också en del av möjligheten att uppleva byggnaden som den var avsedd. Den här undersökningen syftar därför till att lyfta belysningens påverkan på byggnaders kulturhistoriska värden. Genom fallstudier har två höghus i Stockholm uppförda under 1960-talet undersökts: femte Hötorgshuset och DN-huset. Båda byggnaderna har eller har haft en ursprunglig exteriör belysning. Genom en intervjustudie har olika professioners synsätt på belysning som en del av byggnaders uttryck studerats. Undersökningen visar att belysning kan ha stor påverkan på kulturhistoriska värden, inte minst på upplevelsevärdet. Det framkommer också att befintlig lagstiftning kan tillämpas för att skydda en ursprunglig belysning. Undersökningen argumenterar för att det finns vissa skillnader i olika yrkesgruppers synsätt, men att skillnaderna inte har någon större påverkan på bevarandet av belysning. / During the 20th century, electric lighting has been used as a part of the design of buildings, with permanent facade lighting as an integral part of the architecture. When an original facade lighting disappears of changes, part of the possibility to experience the building as it was intended is lost. This study therefore aims to highlight the impact of lighting on buildings’ cultural significance. Through case studies, two high-rise buildings in Stockholm built during the 1960s have been studied: the fifth Hötorgshuset and DN-huset. Both buildings have or have had an original exterior lighting. Through interviews, different professions’ view on lighting as part of the expression of buildings have been studied. This study concludes that lighting can have a great impact on cultural significance, not least in how lighting affects the perception of buildings. It also shows that existing legislation can be applied to protect original lighting. This study argues that there are some differences in the different professions’ views, but that these differences have no major impact on the preservation of lighting.

En studie i undersökningen av takpotentialen på Hötorgshuset 5 i Stockholm. / An investigation of a rooftop potential of Hötorget Building 5 in Stockholm. This project proposes a program on floor 17, 18 and 19 (rooftop level) of the high-rise building containing a restaurant and a health centre with fitness facilities, group training and hamam-inspired steam sauna. The challenges have been to fit in a program in a space traditionally meant only for office use. The aim has been to provide a business that is useful for the place but at the same time provide architectural qualities by structural alterations to make vertical spaces with skylight, maximizing sightlines, keeping constant access to the façade and thereby access to the view outside. Other aims have been to create a brand and identity by adding an oriental hamam-theme into the project. Lastly the project intended to catch the “natural qualities” that are offered by a place of this height by giving access to the roof-top and letting the visitor experience the open sky and the city panorama throughout the year.