Article 662. Effects of extinguishment of the right of superficies
(1) In the case provided by Article 660(a), the construction which formed the object of the right of superficies, as of the date of extinguishment of the superficies, becomes an essential part of the land under Article 460, belonging to the owner of the land, and the right of the superficiary over the land and the construction is to be deleted. The owner of the land is obligated to pay an indemnity equal to its market value as at the date of its expiration. The superficiary is not entitled, upon extinguishment of the right of superficies, to demolish the construction or part of it. The superficiary is obligated to hand over to the owner of the land the documentation relating to the building of the construction.
(2) Where the construction was not in existence at the time when the right of superficies was established, and its value is equal to or larger than that of the land, the owner of the land may require the superficiary to purchase the land at the market value it would have had if the construction did not exist. The superficiary may refuse to purchase the land if it removes, on its own account, the building from the land and reinstated the land in its prior condition.
(3) In absence of an understanding to the contrary entered into with the owner of the land, limited proprietary rights consented to by the superficiary are extinguished upon the extinguishment of the right of superficies. Mortgages encumbering the right of superficies are transferred onto the right of indemnity to be received from the owner of the land in the case provided for in paragraph (1), are extended ex legem over the land in the case specified in the first sentence of paragraph (2) or are transferred ex legem onto the materials in the case specified in sentence II of paragraph (2).
(4) Mortgages established in respect of the land during the superficies do not cover the construction when the superficies ends in case of paragraph (1). They are transferred ex legem onto the amounts received by the owner of the land in the case provided for in the first sentence of paragraph (2) or are extended over the right to the entire land in the case provided for by the second sentence of paragraph (2).