I take it that the Deputy is referring to the possibility of a back-dating of eligibility for the Help-to-Buy Initiative, HTB, to before 19 July 2016.
The commencement date for HTB was chosen as it was the date of the launch of, "Rebuilding Ireland - Action Plan for Housing and Homelessness", in which the development of such a scheme for inclusion in the Budget was initially announced. The intention to apply HTB from this date was announced at that time with a view to avoiding any potential interruption in house sales by purchasers who may otherwise have deferred purchases.
Individuals who purchased new homes before the announcement of the incentive did so without the expectation of such a relief. Similarly, those who commenced the draw-down of mortgages in respect of self-built properties before 19 July would also not have expected a subsequently introduced tax relief to be available to them.
As with all time-bound reliefs, there will always be those who just miss out on qualification. However, I do not propose that start date of this measure be changed as to do so would make HTB more costly and less targeted.