14 M.R.S. §6956: Betterments allowed after 6 years' possession

When the demanded premises have been in the actual possession of the defendant or of those under whom he claims for 6 successive years or more before commencement of the action, such defendant shall be allowed a compensation for the value of any buildings and improvements on the premises made by him or by those under him whom he claims, to be ascertained and adjusted as provided.