Statsbygg would like tenders for the following competition. The Opera Hall — condition analysis and proposals for the protection and maintenance of outside marble for mapping and evaluating the need for protection of outside marble on the Opera Hall in a long term perspective.

The condition analysis shall review the reasons for visual and technical changes in the surface of the marble on the Opera Hall building. The analysis shall form the basis for choosing an appropriate cleaning method for the existing surface as well as for future protection, cleaning and conservation methods for the marble.

The assignment is for mapping the current condition, explaining discolouration of the marble as well as working out a system for the protection and future maintenance of the marble roof.

The work shall be of high scientific quality, research based work on the development of methods and products for maintenance.

The aim of the assignment is to choose/develop a good system for the protection and maintenance of outside marble without the actual marble being damaged/weakened. As a part of this it can be appropriate to have a close look at the remains of the previous cover and the stone surface beneath it.

A condition analysis shall be prepared in order to find the reasons for yellow-brown colouration on the marble so that the product requirements can be described. The analysis is meant to provide a picture of the current situation on a detailed level. It is the tenderer's job to assess the registration level.

The work shall, at a minimum, consist of:

A) Mapping visual and technical changes in the surface of the marble.

B) Selection and establishment of a sample section. The sample section shall be tested before, during and after the treatment. The choice of the sample section shall be clarified with Statsbygg.

C) Monitoring studies, which comprise in situ measurements, laboratory analyses of the stone surface and covering and analyses of the air quality and the effect from the base. The results shall form the basis for maintenance recommendations for the marble.

D) Presentation of results in a workshop in which the contracting authority and the tenderer's key person participate.

E) Preparation of a condition report with recommendations and a cost overview. The report shall be easy to understand. It is to be preferably submitted in Norwegian.

The report shall describe the conservation process, which shall consist of a system that shall include:

— Cleaning;

— Surface consolidation;

— Adhesion, sealing;

— Surface protection.

F) Planning improvement processes/best practice.

G) Maintenance plan that can be integrated into the Opera Hall building's Management Plan.