compensation to be determined, in case of dispute, under Part 1 (determination of questions of  disputed compensation) of the 1961 Act( a ).  Protective work to buildings  20. —(1) Subject to the following provisions of this article, the undertaker may at its own  expense carry out such protective works to any building or structure lying within the Order limits  as the undertaker considers necessary or expedient.  (2) Protective works may be carried out—  (a) at any time before or during the construction of any part of the authorised development in  the vicinity of the building or structure; or  (b) after the completion of that part of the authorised development in the vicinity of the  building or structure at any time up to the end of the period of 5 years beginning with the  date of final commissioning.  (3) For the purpose of determining how the powers under this article are to be exercised the  undertaker may enter and survey any building or structure falling within paragraph (1) and any  land within its curtilage.  (4) For the purpose of carrying out protective works under this article to a building or structure  the undertaker may (subject to paragraphs (5) and (6))—  (a) enter the building or structure and any land within its curtilage; and  (b) where the works cannot be carried out reasonably conveniently without entering land  which is adjacent to the building or structure but outside its curtilage, enter the adjacent  land (but not any building erected on it) within the Order limits.  (5) Before exercising—  (a) a power under paragraph (1) to carry out protective works under this article to a building  or structure;  (b) a power under paragraph (3) to enter a building or structure and land within its curtilage;  (c) a power under paragraph (4)(a) to enter a building or structure and land within its  curtilage; or  (d) a power under paragraph (4)(b) to enter and take possession of land,  the undertaker must, except in the case of emergency, serve on the owners and occupiers of the  building, structure or land not less than 14 days’ notice of its intention to exercise that power and,  in a case falling within sub-paragraph (a), (c) or (d) specifying the protective works proposed to be  carried out.  (6) Where a notice is served under paragraph (5)(a), 5(b) (5)(c) or (5)(d), the owner or occupier  of the building, structure or land concerned may, by serving a counter-notice within the period of  10 days beginning with the day on which the notice was served, require the question of whether it  is necessary or expedient to carry out the protective works or to enter the building, structure or  land to be referred to arbitration under article 42(3) (procedures in relation to certain approvals  etc.).  (7) The undertaker must compensate the owners and occupiers of any building, structure or land  in relation to which powers under this article have been exercised for any loss or damage arising to  them by reason of the exercise of those powers.  (8) Where—  (a) protective works are carried out to a building or structure under this article; and  (b) within 5 years beginning with the date of final commissioning for that part of the  authorised development in the vicinity of the building or structure it appears that the  protective works are inadequate to protect the building or structure against damage  ( a ) The functions of the Lands Tribunal under the 1961 Act are transferred to the Upper Tribunal under the Tribunals, Courts  and Enforcement Act 2007 (c.15).  16