(1) For land Which has already been built upon or on which permission to build has already been accorded before the date notified under Sub-section (5) of Section 32, betterment value shalt be the value on that date less the basic value as computed with reference to the date notified under sub-section (4) of that Section less, the estimated cost of improvement work, if any, carried out by the owner betWeen the two dates.
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(2) For land which on the date notified under sub—section (5)] of Section 32 has neither been built upon nor in reSpect of which permission to build has been accmded before that date, the betterment value shall be the value on the date when permission to build is granted less the basic value as computed with reference to the date notified under sub-section (4) of Section 32, less the estimated value of improvement,if any, carried out by the owner between the two latter dates.