In my opinion, any extension of the current RPZ regime (as speculated on other threads) beyond what is contained in the current legislation would be unconstitutional
Back in 1981, the Supreme Court declared certain parts of the Rent Restrictions Act, 1960 (as amended), to be invalid having regard to the provisions of the Constitution.
The Court's conclusion was that the rent control and certain other provisions contained in that Act were so restrictive, intrusive and unfair as to constitute an unjust attack on landlords' property rights.
In particular, the Court found that the legislation then impugned "applied only to some houses and dwellings and not to others; that the basis for the selection is not related to the needs of the tenants, to the financial or economic resources of the landlords, or to any established social necessity; and that, since the legislation is now not limited in duration, it is not associated with any particular temporary or emergency situation."
In other words, the automatic expiry of the designation of an area as a RPZ after three years was a deliberate attempt to avoid a successful constitutional challenge to the RPZ regime.
Back in 1981, the Supreme Court declared certain parts of the Rent Restrictions Act, 1960 (as amended), to be invalid having regard to the provisions of the Constitution.
The Court's conclusion was that the rent control and certain other provisions contained in that Act were so restrictive, intrusive and unfair as to constitute an unjust attack on landlords' property rights.
In particular, the Court found that the legislation then impugned "applied only to some houses and dwellings and not to others; that the basis for the selection is not related to the needs of the tenants, to the financial or economic resources of the landlords, or to any established social necessity; and that, since the legislation is now not limited in duration, it is not associated with any particular temporary or emergency situation."
In other words, the automatic expiry of the designation of an area as a RPZ after three years was a deliberate attempt to avoid a successful constitutional challenge to the RPZ regime.