University of Oslo, Domus Media

In earlier renovations different types of materials have been used. Thorough investigations carried out by prescribers found a patchwork of renders and differing quality levels, all based on lime and cement. Close contact between prescribers, applicators and Weber as a material provider have given the best foundation for preservation and renovation of these façades. 

 

Map of Norway

Norway
Oslo
Contractor
Statsbygg on behalf of University of Oslo. Applicators: Thorendahl as, Malercompagniet as, SRA as.
Project Date
2011-2013

Issues and stakes

The 5 buildings are made of solid brickwork masonry with weak hydraulic limes in both bedding mortars and renders, while the new atrium has mortars and renders based on weak lime-cement mortars. The foundations are made of local granite blocks, protecting most of the brickwork and renders from capillary moisture. The buildings have been through at least 3 earlier renovations, and some of the original renders were still present. Patches of renders had a lack of adhesion to the substrate. Silicate paint was used in the latest renovation 20 years ago. These renovations in particular have made this task a challenging exercise considering the mix of different renders in a kind of patchwork. Another issue to consider was the high level of graffiti on façades and heavy traffic flowing towards public areas. A main issue was executing the renovation while the buildings were still in use. 

Domus Academica was bestowed a Europa Nostra Award in 2006 - the European Union prize for cultural heritage, in the category of conservation. The jury mentions in their reasoning “…one of Europe’s most beautiful, Neoclassical buildings”. The same building was given the Oslo Municipality Award for good city architecture the same year. The original buildings are brickwork masonry with weak hydraulic limes in both bedding mortars and renders, while the atrium has mortars and renders based on weak lime-cement mortars. The foundations are made of local granite blocks, protecting most of the brickwork and renders from capillary moist. The buildings have been through at least 3 earlier renovations, and some of the original renders are still present. These renovations have made this task a challenging exercise considering the mix of different renders in a kind of patchwork. The buildings are planned and built by the Norwegian architect Christian H. Grosch, with help from the famous German architect Karl Friedrich Schinkel. Although the University was founded in 1811, work didn’t start until 1841 and was finished in 1852. Domus Media was extended for its 100th anniversary in 1911, with an atrium to the rear in the gardens. The architects for this extension were Harald Bødtker and Holger Sinding-Larsen. The atrium contains some of the more famous paintings by Edvard Munch (http://www.munch150.no/en/Programme/The-University-Aula-927638).

Achievements

The complexity of the patchwork lead to a detailed programme for renovating the façades with the aim of preserving most of the original renders. Different materials and working methods had to be considered before settling on the right mix. The choice of paint tries to blend in with the original lime paint and meet today's demand for durability and maintenance. The thorough pre-project work and close collaboration between stakeholders have set a benchmark for future large-scale projects. Sound knowledge of materials and construction made it easier to choose the right material mix and time schedules set by the building owner. Lime-based materials have been used throughout the project, with a mean thickness of 4 cm, varying from 1 cm to 11 cm. Different paints were tested according to application, transparency, colour, graffiti-resistance and durability. This lead to the choice of a dry-powder, NHL-based paint in 3 layers. Lime-cement-based materials and silicate paint have been used in high traffic areas, and anti-graffiti solutions based on low-temperature wax have been used to protect exposed areas.

Weber have provided hydraulic limes based on NHL for renovation of the façades for all 5 buildings on the site - a total of approx. 13,000 square metres. The project started in 2011 and lasted until 2013. The project also included the repointing of foundations with special mortars, lime-cement-based paints for decorations, anti-corrosion materials for beams and lime paint for interior use. NHL-based mortars have been used for masonry and renders. Wet lime and NHL lime have been used in the restoration of the roof in the entrance to the atrium. Wet lime has been used for stucco lustro in the entrance.