⚡ Summary
If you are valuing a tenanted investment property in Ireland today, you need two rental figures where you previously needed one. The March 2026 rent cap — a national HICP-indexed ceiling applying to every private tenancy — means the permitted rent on a sitting tenancy is no longer the same as open market value. The gap between those two figures is a tenancy-level encumbrance, and its size depends entirely on one piece of documentation: the date of the last formally recorded rent review.
What Actually Changed in March 2026
Before 1 March 2026, statutory rent review ceilings only applied inside designated Rent Pressure Zones (RPZs) — primarily Dublin, Cork city, Galway city, and a number of specific towns. Outside those zones, landlords could increase rent to open market value at any review point. There was no cap.
The Housing (Miscellaneous Provisions) Act 2026 changed that. Since March 2026, every residential tenancy in the Republic of Ireland — RPZ or not — is subject to a national HICP-indexed rent cap. The cap calculation runs from the documented date of the last rent review on that specific tenancy, and the permitted increase is subject to an annual maximum.
For properties inside former RPZs, the operational change is marginal — the cap mechanism was already familiar. For properties that sat outside RPZs, the change is structural. Landlords who historically raised rents to open market value without documenting a formal review date are now in a materially different position. So, in turn, are the professionals valuing those properties.
The Valuation Problem This Creates
Before March 2026, valuing a tenanted property outside an RPZ was straightforward: open market value and the achievable rent were the same figure. The sitting tenancy was not an encumbrance on rental income — it was, at most, a question of timing.
That is no longer the case. Two rental figures now need to be modelled for any tenanted property:
- Open market value (OMV): what the property could achieve if let fresh to a new tenant today.
- Cap-constrained permitted rent: the maximum that can legally be charged on the sitting tenancy, calculated from the documented last review date using the HICP cumulative inflation formula.
Where those two figures diverge, the gap is not trivial. It affects yield, and through yield it affects capital value. For investment valuations, the gap between OMV and the permitted rent on the sitting tenancy is a tenancy-level encumbrance that must be modelled explicitly — not absorbed into a general discount.
Consider a property let in 2022, with the last rent review formally documented in January 2023. The cap calculation runs from that documented date. The permitted increase is the HICP cumulative inflation from January 2023 to the current review date, subject to the annual maximum. The OMV may have moved substantially in the same period — the gap between that and the permitted rent is the encumbrance on yield.
If there is no documented last review date, that calculation is contestable. The permitted rent figure becomes uncertain. A valuation built on an uncertain permitted rent figure is itself uncertain — and that uncertainty has to go somewhere in the report.
Three Areas of IPAV Work Most Affected
- Investment valuations on tenanted properties. Before March 2026, OMV and permitted rent were the same figure for non-RPZ properties. Now, both figures must be modelled and the gap between them quantified. Where the sitting tenancy has a documented review history, the calculation is mechanical. Where it does not, the valuer is in the position of having to note the absence of that documentation and qualify the income figure accordingly.
- Landlord advisory. The question "what can I charge?" is no longer a market question alone. It requires the documented last review date before any permitted figure can be given. A client presenting a tenancy with no formal review records — common for properties that sat outside RPZs before March 2026 — needs to understand that the calculation cannot be completed without first establishing whether that date exists and where it is recorded.
- Estate, probate, and finance valuations. Rental income projections on tenanted properties should reflect the cap-constrained permitted figure — not OMV — for the duration of the existing tenancy. Where the review documentation is incomplete, that projection carries a qualification. For probate and finance valuations in particular, where the income figure feeds directly into asset valuation, the documentation gap is a material issue that needs to be surfaced rather than assumed away.
The Documentation Gap
The landlords most exposed to this issue are those whose tenancies sat outside RPZs before March 2026 and who historically raised rents informally — to market rate, without issuing a formal notice of rent review or maintaining a written record of the review date.
In those cases, the last documented review date may be the original tenancy commencement. Or it may exist in a piece of correspondence that neither the landlord nor tenant can readily locate. Or it may genuinely not exist in any form that would survive scrutiny at an RTB dispute hearing.
For the IPAV professional advising these clients, the first practical step is establishing whether the review date exists and where it is recorded. That is not a legal question — it is a factual one. The answer determines whether the cap calculation can be completed and, if so, what the permitted rent figure is. Without it, any income figure used in a valuation carries a qualification that reflects the documentation uncertainty.
⚠ Long-running tenancies carry the highest risk
Landlords with tenancies that predate the current RTB annual renewal regime are particularly exposed. Review history in those cases may exist only in correspondence — informal emails, text messages, verbal agreements — none of which constitute a formally documented review date for cap calculation purposes. Where this situation is identified, it should be surfaced early in any advisory engagement.
The same issue arises for investors acquiring tenanted properties. Inherited tenancy documentation is often incomplete, and the question of what review date the incoming owner can rely on for the first post-acquisition review is one that needs to be answered before closing — not after.
Managing rent review documentation? TenantSync tracks per-tenancy review dates and calculates the permitted increase under the HICP cap — one place for the records that now underpin every rental valuation.
See how it worksHow TenantSync Helps
TenantSync tracks per-tenancy review dates, calculates the permitted increase under the HICP cap, automates RTB registration and annual renewal, and maintains a single compliance record per tenancy. For property professionals who advise landlord clients or manage tenancies directly, it provides the documented audit trail that makes the permitted rent figure defensible — at valuation, at review, and at dispute.