Though opinions on the aesthetic appeal of the building designed by architect Gunars Birkerts were divided (and remain so) from the start, at least people agreed on one thing - it merited its name as the "Castle of Light" in allusion to a Latvian folk tale.
Recently however it has acquired a grey tinge that's less apparent this summer only due to the lamentable lack of direct sunlight.
The cleanup will take five weeks and cost the state €117,694.
Indriķis Builis, a representative of the Culture Ministry, said it's hoped that the building will not have to be cleaned each year.
The total area to be washed, including the roof and the windows, is around 22,000 square meters, which equates to an awful lot of chamois action. The roof is to be covered with special dirt-repellent chemicals.
While according to engineers and cleaning experts at the National Library, the outside of one of the major buildings in Rīga's historical skyline would have to be cleaned once in a year or a year and a half.