Researching an area before you buy in Dublin

Dublin is the hardest place in the country to research from public data and the place where it matters most, because prices vary more between two roads than they do between two counties elsewhere. The register will help you, but only after you have understood that the city describes itself in three different geographies at once and the register uses none of them.

Three geographies, none of them the same

The register gives you a county, and for Dublin that single value covers well over a million people and four separate local authorities: Dublin City, Fingal, South Dublin and Dun Laoghaire Rathdown. Filtering by county Dublin is therefore not a filter at all. Everything useful has to be done on the address text, which was typed by the solicitor who filed the return and follows no house style.

• Postal districts. The numbered districts run from Dublin 1 upward, with odd numbers north of the Liffey and even numbers south, plus the well known separate district of Dublin 6W. They appear in address text as often as not, and they are the geography most Dubliners actually think in.
• Eircode routing keys. The first three characters of an Eircode identify an area, and Dublin uses D01 through D24 alongside keys such as A94, A96 and K67 for districts outside the numbered system. On rows that carry an Eircode this is the most reliable geography available.
• Local authority areas. These govern planning, development plans, local charges and services, and they cut across postal districts in ways that surprise people who have only ever thought in numbers.

The practical rule is to search on the smallest text you trust. An estate name, a road name and a district number will get you further than any county filter, and where the rows carry Eircodes the routing key gives you a clean and consistent boundary. Older rows carry no Eircode at all, for reasons covered in why the register has no Eircodes for older sales.

Reading an estate from the register

Once you have a set of rows for a single estate, three things are worth reading in order. First the count: how many homes changed hands in the past two years, because a road that turns over twice a decade tells you something different from one that turns over constantly. Second the middle: where the bulk of the prices sit once the not full market price rows are removed. Third the spread: whether the estate prices tightly, which suggests uniform housing stock, or widely, which usually means extensions and condition are doing the work.

That third reading is the one most people skip and the one that pays. A wide spread in an estate of nominally identical houses is an invitation to find out which end of it the house you are viewing belongs to, and why. Grouped views of the same rows are on our Dublin sold price pages, which saves the assembling.

Traps that are specific to Dublin

One more Dublin habit is worth unlearning. Buyers arrive with a district number in their head and treat it as a price band, which it has not been for a long time. Individual roads inside a single district can differ by a wide margin depending on the vintage of the housing, the size of the gardens, the width of the road and whether the terrace was built for one purpose and later converted for another. Search the road, then check whether it behaves like its district, and be prepared to find that it does not.

What the register cannot tell you about an area

The register holds prices. It holds nothing about the things that will decide whether you are happy living somewhere: schools and their catchments, the actual walk to a Dart or Luas stop as opposed to the distance on a map, flood history, the planning application for the field behind the estate, whether the road is a rat run at half past eight, or how the block is managed and what the service charge is doing.

For the population side of that picture, the Central Statistics Office publishes census results down to small areas, which will tell you about household composition, tenure mix and how people in that area travel to work. For everything else, the local authority development plan and the planning register are public, and reading the applications within a few hundred metres of a house you are serious about is an hour that regularly changes minds.

The tests only a visit can run

• Go at rush hour and again on a Sunday morning. The same road can be two different places.
• Walk the actual route to the school, the station and the shop, with the buggy or the bike you will really be using.
• Stand outside at night. Lighting, noise and how overlooked the front of the house feels are not in any dataset.
• Look at the neighbours' windows and gutters, which tell you whether an estate is being maintained.
• Check where the bins go, where visitors park, and whether the green space belongs to somebody who cuts it.

A research order that works

1. Pick the smallest geography you can name: the estate, the road, or the routing key.
2. Pull two years of register rows for it, remove the not full market price rows and separate new builds from second hand.
3. Read count, middle and spread before you look at any individual house.
4. Check the pattern against the wider district using the Dublin data, so you know whether the road is expensive or the area is.
5. Bring in the things the register does not hold: census profile, development plan, planning applications, transport.
6. Only then start viewing, with a price range in your head that came from evidence rather than from an agent.

That order matters because it puts the numbers before the emotion. Once you have stood in a kitchen you like, every figure you read afterwards will be recruited to justify the decision you have already made. Doing the register work first is the cheapest possible insurance against that.

Sources: sale prices from the Residential Property Price Register, published weekly by the PSRA from stamp duty returns. Area statistics including census small area profiles are published by the Central Statistics Office. Valuation method: valuing a home from register comparables.