Two official numbers describe Irish house prices, and they rarely agree. The Property Price Register tells you what individual homes actually sold for. The CSO's Residential Property Price Index tells you which way prices are moving. Buyers reach for the register, quote a median, and then wonder why the headlines say something different. They're measuring two different things from the same raw data. Here's what the index is, why it disagrees with a register median, and how to use both without fooling yourself.
What the CSO house price index is
The Residential Property Price Index (RPPI) is the official measure of change in the price of homes sold in Ireland, published every month by the Central Statistics Office. It is built from the same source as the Property Price Register: the stamp-duty returns Revenue receives on every residential sale. The CSO then matches those sales to Building Energy Rating (BER) records from the SEAI to pull in details about each property.
The key word is index. The RPPI is not a price in euro; it is a number relative to a base period, which the CSO sets at 100 for the 2015 annual average. When commentators say “prices rose 3% over the year”, they mean the index moved 3%, not that any particular house did. For an actual euro figure you still need the register.
Source: Central Statistics Office, cso.ie
Two measures, one source, different jobs
Both numbers come from the same Revenue filings, so why do a register median and the index tell different stories? Because a raw median mixes up two things a buyer wants kept apart: did prices change and did the mix of homes sold change. If a quiet month happens to include more big detached houses, the median jumps even if no individual home got dearer.
The index is built to strip that out. It uses a hedonic, quality-adjusted method: a rolling 12-month regression that controls for the characteristics of what sold, so it compares like with like from one period to the next. That's the difference in one line:
| Property Price Register | CSO price index (RPPI) | |
|---|---|---|
| What it gives you | The euro price each home sold for | The change in prices, as an index |
| Adjusts for the mix? | No — a raw list of sales | Yes — quality-adjusted, like-for-like |
| Best for | “What did this house sell for?” | “Which way is the market moving?” |
| Cadence | Updated as returns are filed | Monthly, national and by region |
Source: CSO Residential Property Price Index background notes; Property Services Regulatory Authority, propertypriceregister.ie
Reading the index without over-reading it
The CSO publishes a national index plus breakdowns by region (Dublin and the rest of the country) and by dwelling type. A few things are worth knowing before you quote a figure:
- It is smoothed on purpose. The CSO applies a statistical smoothing technique to the underlying series to damp short-term noise and surface the longer-term trend. A single month's wobble may be residual volatility, not a turning point, so read the direction over several months.
- New builds are reported quarterly, not monthly. There are too few new-dwelling sales each month for a stable monthly figure, so the CSO pools them into quarters at national level. Existing homes are the bulk of the monthly index.
- It arrives in arrears. Each release covers a month that has already closed, several weeks earlier, because sales have to be filed and processed first. The index tells you where the market has been, not where it will be next week.
A register median is not the market rate
It's tempting to average the last few sales on a street and call it “the price”. With a handful of transactions, one big or unusual sale drags that average around. The index exists precisely because small samples and a shifting mix mislead. Use the register for the specific comparable homes; use the index for the trend.
Using both when you're buying
The two measures answer different questions in a purchase, and you want both:
- Pull the register for what genuinely comparable homes on the same street or estate sold for, and anchor your maximum bid on those euro figures.
- Check the index for direction and pace: is the market rising, flat or softening, nationally and in your region? The latest figure always lives in the newest CSO release.
- Remember what neither captures: the condition, flood or radon exposure, planning history or energy cost of the actual home in front of you. Price context is one input, not the decision.
A PropertyPack report gathers the local price context for you: it pulls recent registered sales around the property's Eircode and shows them beside the area's other official signals. The national property-prices guide explains the data, and each county hub carries local sold-price context, for example house prices in Dublin.
Sold-price context is one of 18 checks in every report
Alongside recent registered sale prices, a PropertyPack report answers flood, radon, BER, planning and the rest for any Eircode: 18 official checks with a free snapshot in about a minute. Working out your budget? The buying checklist shows where the price check fits in the sequence.
About this article
Written by the PropertyPack.ie team and published 31 August 2026. Figures render directly from the official datasets behind our reports, so they update when the underlying record does. General information for Irish home buyers, not legal, financial or tax advice.
