The maps below show the Norwegian municipalities that imposed boplikt (a residency requirement) on owners of residential properties between 1975 and 2015. Boplikt is indicated by red shading, with light shading indicating that the policy was only imposed in part of the municipality.
Norway introduced boplikt in 1974 as a policy to prevent local communities from being hollowed out by housing being held by residents of other locations who are absent most of the time. Under the policy, the owner of a property is required to live in it a majority of nights of the year, to rent it out, or to sell it. Each municipality chooses whether to impose the policy -- the number of municipalities that did so grew steadily until about 2005 and then declined somewhat in the decade thereafter. By 2016, 92 of the 428 municipalities in Norway had imposed the policy for some period of time.
A selection of the maps appear in the paper Sheard, N., 2019, “Vacation Homes and Regional Economic Development”, Regional Studies 53(12), 1696–1709, which analyses the effects of the policy on economic development in the Norwegian regions.