The Fire-Insurance order for merchant places in Norway from August 18th 1767 introduced fire insurance i the cities in Norway. All the house owners was ordered get an assessment on the value on their houses. This should be done by knowledgeable men, that was to be appointed by the Magistrate in the city. The same order gave also the house-owners out in the country the same opportunity. But it is rare that we find fire value assessments of houses outside of cities further back than 11845. That's the year the law about an all out fire assurance organization for buildings.
The assessment value put on the houses for insurance is a very useful source for information about older houses. With these we get knowledge on when the house was built for the houses built the last 250 years and about any modifications made to old houses.
What you'll find at Digitalarkivet is the registers to the protocols
These are all the registers available on Digitalarkivet