Babelsberg

Project Report 2

Restored building façade brings old splendor to world heritage site

Babelsberg Palace in , , shines again in imperial splendor after a 3 year restoration of its façade that placed high demands in the area of monument protection. During the renovation of the striking window surfaces, SCHOTT mastered tricky challenges with its restoration glass GOETHEGLAS.

The History The prominent Prussian architect Karl ­ and Gardens Foundation Friedrich Schinkel, his pupil Ludwig -Branden­burg (SPSG), Babels- Persius, and the architect Heinrich berg Palace and Park have now been Strack erected in UNESCO World Heritage sites since two construction sections between 1990. The Foundation wants to use the 1833 and 1849 for the future emperor monument as a museum again in the Wilhelm I. The summer residence in future and designed a master plan for neo-Gothic style spared no expense on the r­estoration of both the palace and façade materials such as brick, natural the park, which began in 2013 with the stone, terracotta, Roman cement, and ­restoration of the exterior. zinc castings. The 380 different exterior door and window elements make for The Challenge a real eye catcher, with a glazed area of The task of exterior restoration came 550 m² (5,920 sqft.) including large for- with rigid conservation requirements, mat all glass windows that offer an un- considering the diverse building mate- obstructed view of the magnificent nat- rials and styles, differing periods of construction and energy requirements ural park. ­material origin, execution standards, had to be taken into account. After all, and conservation conditions. This the renovation was ultimately aimed at After the death of Wilhelm I, the impe- challenge pertained particularly to the making the building usable as a museum. rial palace was used in a variety of ­historical windows, which remained ways, but the construction material largely intact, but were severely im- The Solution was ­neglected. Owned by the Prussian paired by years of reconstructions and After carefully examining samples, the additions, including the addition of building owners and the architects new window levels and the use of mod- from Dr. Krekeler Generalplaner GmbH ern float glass. The impressive large in chose GOETHEGLAS scale glazing was damaged during from SCHOTT as their restoration glass. World War II and equipped with glaz- The special Fourcault production pro- ing bars and transoms to subdivide the cess gives the colorless drawn glass the window surface during repair. irregular surface characteristic of win- dow glasses from the 18th and 19th Such subsequent, stylistically inappro- centuries. At the same time, it enables priate changes had to be removed modern functions such as UV protec- ­according to the master plan. Historical tion and thermal insulation and can be glazing was to be maintained as much further processed into insulating glass, as possible, while float glass was to be laminated glass, or tempered glass. replaced by a more authentic glass with a slightly wavy appearance. Besides SCHOTT’s processing know how ­historic preservation aspects, modern was a decisive factor for achieving the 3

planned glazing solutions. For exam- strengths, glass structural engineers received positive feedback on the result ple, SCHOTT produced GOETHEGLAS from SuP Ingenieure GmbH in Darm- from all sides.” three meters long for the Babelsberg stadt were contracted to examine the project, refined by means of thermal suitability of the glazing from a static Stefan Gubelt, Dr. Krekeler General­ pre-stressing and subsequent heat perspective. The all glass and laminated planer GmbH, Berlin soaking tests. This allowe d for a large glass windows therefore meet the share of the all glass windows to be safety requirements of ESG-H glazing Statement from the building owners: installed. The 4.5 meter (14.8 ft.) high and have received extensive approvals “We wanted to have a restoration glass special formats on the main floor of the from the building authorities. that would attract the attention of view- palace were designed as laminated glass ers, but with a wavy appearance that is with butt joints. In addition, insulating “SCHOTT was the only company to offer less obtrusive. We are very pleased with glass with an outer pane made of a three meter restoration glass with the our decision in favour of SCHOTT and GOETHEGLAS and an inner pane made matching aesthetics at the time of plan- its GOETHEGLAS, ­especially since the of float glass was produced to address ning. In close collaboration, we were refurbishment of the glazing had to specific climatic concerns. also able to meet the high demands of meet a wide range of requirements.” monument protection as well as the Although all SCHOTT restoration static, energetic, and constructional Max Daiber, Project Head at the Prussian glasses have European technical ap- challenges that pertain to insulation Palaces and Gardens Foundation Berlin- proval that regulates the framework and composite glass solutions. We are Brandenburg conditions and characteristic bending very grateful for this because we have

THE MATERIAL

• GOETHEGLAS / 4.5 mm (0,18”) thick • with thermal tempering and heat soaking • as laminated glass with laminated GOETHEGLAS and butt joints • a s insulating glass with 6 mm and 8 mm (1/4” and 5/16”) spacer SCHOTT North America, Inc. 5530 Shepherdsville Road Louisville, KY 40228 USA Phone +1 (502) 657-4417 [email protected] www.us.schott.com/restoration

PFLY_0043_OM ENGLISH/US 06/2020 kn/odd Printed in Germany