Ireland has some of the best open rent data in Europe. The Residential Tenancies Board (RTB) records the rent of every new tenancy, and the Central Statistics Office (CSO) publishes the averages, every half-year since 2008, for counties, towns and small areas.
I wanted to use it for a quick analysis and found the raw table hard to work with. So I cleaned it properly and published the result as an open dataset on Kaggle and Hugging Face.
What’s wrong with the raw table
The CSO table (RIH02) has 674,352 rows. Three things make it awkward:
- Every category appears twice, once as a code and once as a label, plus columns that never change.
- Places of very different sizes are mixed together: counties, towns, Dublin postal districts and small areas sit in one column with nothing saying which is which.
- 70% of the rent cells are empty.
Empty doesn’t mean zero
The empty cells are the most important part. The RTB leaves a cell empty when too few new tenancies were registered to give a reliable average. It’s mostly small areas and specific bedroom counts: 86% of “one bed” cells are empty, against 50% for “all bedrooms”.
If you load the file and fill those gaps with zeros, or let a tool do it quietly, every average you compute is wrong. So I dropped them and wrote down why in the data card. 201,912 published rents remain.
Labelling places: my first try was wrong
I first guessed each place’s level from the CSO’s location codes, assuming counties ended in four zeros. The check I printed found only 4 “counties”, and one of them was Christchurch, an area of Dublin city. So the guess was wrong, and the printout caught it before anything was published.
I switched to matching the 26 county names. Everything without a comma (“Carlow Town”, “Dublin 8”) is a town or district, and everything with one (“Tullow, Carlow”) is a smaller area: 26 counties, 36 towns and districts, 375 areas.
Totals, flagged
“All bedrooms”, “1 to 2 bed” and “All property types” are sums of other rows. Leaving them unmarked invites double counting, so each row has two true/false columns that say whether it’s a total.
Checks, then publish
Before anything goes out, the pipeline asserts one row per half-year, place, bedrooms and property type, and that every rent is between €50 and €20,000. A GitHub Actions workflow downloads the official table, cleans it, publishes the files with a data card, and runs the same code as a Kaggle notebook. Both produce the same 201,912 rows. The code is on GitHub.
What 18 years of rents show
Average monthly rent for a new tenancy, all homes:
- Dublin fell from €1,325 in early 2008 to €1,004 in early 2011, then more than doubled to €2,162 by late 2025.
- Over the last ten years, rents at least doubled in 17 of 26 counties. The biggest rises were in Longford (+156%), Limerick (+146%) and Roscommon (+133%). Dublin rose 67%, from a much higher base.
- Late 2025, the most expensive counties were Dublin (€2,162), Wicklow (€1,739) and Kildare (€1,719). The least expensive were Donegal (€992), Leitrim (€1,010) and Monaghan (€1,034).
These are averages for new tenancies, not what all tenants pay, and they aren’t adjusted for inflation. The chart is on the project page.
What I’d do next
- Adjust for inflation using the CSO’s consumer price index, so 2008 and 2025 rents can be compared fairly.
- Add tenancy counts, if the RTB publishes them, so users can see how reliable each average is.
The dataset is free to use under CC BY 4.0. If you build something with it, I’d love to see it.