(1) Chapter 10 of Part 10 of the Principal Act is amended -

(a) in section 372AA -

(i) in subsection (1) in the definition of "qualifying period" -

(I) in paragraph (b) by substituting "31 December 2006, or" for "31 July 2006;" and

(II) by inserting the following after paragraph (b):

"(c) where subsections (1A) and (3) apply, 31 July 2008;",

and

(ii) by inserting the following after subsection (2):

"(3) Subject to paragraphs (a) and (b) of section 270(7), this subsection shall apply in relation to the construction or refurbishment of a building or structure or part of a building or structure the site of which is wholly within a qualifying area where -

(a) the person who is constructing or refurbishing the building or structure or the part of the building or structure has, on or before 31 December 2006, carried out work to the value of not less than 15 per cent of the actual construction or, as the case may be, refurbishment costs of the building or structure or the part of the building or structure,