New-build apartments and student housing: the CPI-only rule

If you rent a newly built apartment or new student-specific accommodation, check the date on the building's commencement notice. Where it was lodged on or after 10 June 2025, the rent may rise with the Consumer Price Index alone. The 2% ceiling does not apply. Everything else does: a review once in any 12 months, at least 90 days' notice in the prescribed form, three comparables, a copy to the RTB, and never above market rent.

This month the rule makes a difference. The CPI figure for September 2026 is 4.1%, which is above 2%, so an older home is capped at 2% while a new building under the rule can rise by 4.1%. The rule bites whenever inflation runs above 2%, as it did through 2022 and 2023 and does again now. The rent increase checker asks whether your home is under the rule and applies the right figure.

The rule

Since 1 March 2026 the ordinary cap on a rent increase is the lower of 2% and the annual change in the CPI. For two kinds of home the Act drops the 2% arm and leaves the CPI alone. They are a newly built apartment and new student-specific accommodation, in each case where the commencement notice was lodged on or after 10 June 2025.

The rest of Part 3 applies as it does to every other tenancy. A review can happen once in any 12 months. The landlord must serve a review notice at least 90 days before the new rent starts, in the prescribed form. It must carry the RTB calculator printout and three comparable tenancies from the Rent Register, and a copy must reach the RTB within 7 days. The new rent can never be above market rent. Rent increase rules from 1 March 2026 is the full rule.

The rule was made to encourage apartment building. It is a cap on the increase, not a removal of the cap, and it does not allow a reset to market at any point the ordinary rules would not.

Which homes it covers

The test has two parts, and both must be met.

The home must be a newly built apartment or new student-specific accommodation. An apartment is a self-contained dwelling in a building of several. A house is not covered, however new. An older building converted into apartments is a harder case, and the commencement notice for the conversion is where the answer lies.

The commencement notice must have been lodged on or after 10 June 2025. A commencement notice is the document a builder lodges with the local building control authority before work starts. The date is fixed, it is on the public record, and the landlord knows it. A building finished in 2026 whose commencement notice was lodged in 2024 is not covered.

How to tell if yours is one

Ask the landlord in writing which date the commencement notice carries and which authority holds it. The letter builder has a confirm-in-writing letter you can adapt. A landlord relying on the rule should be able to answer in one line.

Look at the review notice. A notice that applies CPI above 2% should say that it does and why. A notice that applies more than 2% and says nothing is a notice to question.

Look at the rent-setting statement you received at the start of the tenancy. Since 1 March 2026 it names the previous rent and when it was set. For a building first let in 2026 there is no previous rent, and the statement should say so.

If the landlord will not answer, the RTB can be asked. The commencement notice is also searchable on the local authority's building control register, and Threshold on 1800 454 454 can help you find it.

What the difference is worth

The difference compounds. Over a six-year cycle with inflation at 4% the gap between the two caps is several hundred euro a month. That is why the rule is worth checking when you take a new-build apartment, even in a year when the two caps happen to match.

The exemptions people search for

The Rent Pressure Zone exemptions were written for the zones, and the zones ended on 28 February 2026. Rent Pressure Zones: what replaced them explains the change.

From 1 March 2026 there are three questions to ask instead. Is the home a new apartment or new student accommodation with a commencement notice from 10 June 2025, so that CPI alone applies? Was the home empty for two years, or one for a protected structure, so that it may be let at market? And did the tenancy begin on or after 1 March 2026, so that it may be reset at the end of a six-year cycle or after a tenant-led ending? When rent can be reset to market covers the last two.

If the landlord claims the rule wrongly

Keep paying the current rent. Write to the landlord asking for the commencement notice date in writing. If the answer shows the rule does not apply, or no answer comes, refer a dispute to the RTB at least 28 days before the new rent would start. The review is paused while the dispute runs.

The RTB can order rent paid over the cap repaid, with damages of up to €20,000. Since 14 September 2026 it can also serve the landlord with a fixed payment notice of €200 for a rent breach. Challenging a rent increase at the RTB takes you through the application.

Where this leaves you

A new-build apartment or new student accommodation with a commencement notice lodged on or after 10 June 2025 may rise with CPI alone; every other home is capped at the lower of 2% and CPI. This month that is 4.1% against 2%, so the rule is worth €42 a month on a €2,000 rent. The date on the commencement notice decides, and the landlord should give it to you in writing. Run the notice through the checker with the right setting, keep paying the current rent, ring Threshold, and refer a dispute in time if the rule has been claimed without the date to support it.