1. A real property tax exemption pursuant to this title shall be granted to an applicant who, within a period of thirty-six months, or following an extension pursuant to section four hundred eighty-nine-hhh of this title within a period of forty-eight months, from the date of issuance of a certificate of eligibility has completed reconstruction or construction work in accordance with the plans approved by the board in the certificate of eligibility. The amount of the tax exemption shall be determined as follows:

1. (a) In the case of an applicant who has completed industrial construction or reconstruction work, or commercial reconstruction work designated as of right pursuant to section four hundred eighty-nine-ccc of this title or as specially needed pursuant to section four hundred eighty-nine-eee of this title, the tax exemption shall continue for nineteen tax years in an amount decreasing by five per centum each year from an exemption of ninety-five per centum of the exemption base, as defined in paragraph (d) of this subdivision.
2. (b) In the case of an applicant who has completed other commercial reconstruction work, or new commercial construction work designated as of right pursuant to section four hundred eighty-nine-ccc of this title or as specially needed pursuant to section four hundred eighty-nine-eee of this title, the tax exemption shall continue for ten tax years, in an amount decreasing by five per centum each year from an exemption of fifty per centum of the exemption base.
3. (c) In the case of an applicant who has completed other new commercial construction work, the exemption shall continue for five tax years in an amount decreasing by ten per centum each year from an exemption of fifty per centum of the exemption base.
4. (d) The term "exemption base" shall mean the difference between the final assessed value of the property as determined upon completion of the construction or reconstruction work and the lesser of (i) the assessed value of the property at the time an application for a certificate of eligibility pursuant to this title is made, or (ii) the assessed value as may thereafter be reduced pursuant to application to the tax commission. The tax exemption shall be computed according to the following tables: CONSTRUCTION OR RECONSTRUCTION OF INDUSTRIAL STRUCTURES OR RECONSTRUCTION OF AS OF RIGHT OR SPECIALLY NEEDED COMMERCIAL STRUCTURES Year following Percentage of completion of work exemption
5. 1. 95
6. 2. 90
7. 3. 85
8. 4. 80
9. 5. 75
10. 6. 70
11. 7. 65
12. 8. 60
13. 9. 55
14. 10. 50
15. 11. 45
16. 12. 40
17. 13. 35
18. 14. 30
19. 15. 25
20. 16. 20
21. 17. 15
22. 18. 10
23. 19. 5 RECONSTRUCTION OF OTHER COMMERCIAL STRUCTURES OR CONSTRUCTION OF AS OF RIGHT OR SPECIALLY NEEDED COMMERCIAL STRUCTURES Year following Percentage of completion of work exemption
24. 1. 50
25. 2. 45
26. 3. 40
27. 4. 35
28. 5. 30
29. 6. 25
30. 7. 20
31. 8. 15
32. 9. 10
33. 10. 5 CONSTRUCTION OF OTHER NEW COMMERCIAL STRUCTURES Year following Percentage of completion of work exemption
34. 1. 50
35. 2. 40
36. 3. 30
37. 4. 20
38. 5. 10

2. The taxes payable during the period from the issuance of a certificate of eligibility to the approval of the tax exemption pursuant to section four hundred eighty-nine-fff of this title shall be paid on the lesser of:

1. (a) the assessed value of the property at the time an application for a certificate of eligibility pursuant to this title is made, or (b) the assessed value as may thereafter be reduced pursuant to application to the tax commission, provided, however, that if reconstruction or construction is not completed in accordance with the plans approved in the certificate of eligibility including any amendments thereto, taxes shall be due and payable retroactively as otherwise required by law.