How to Read Property Price Trends: A Data-Driven Guide

Where sold prices come from

In England and Wales, HM Land Registry publishes Price Paid Data: a record of residential sales, each with the price, the date, the property type (detached, semi-detached, terraced or flat), whether it was a new build, and whether it was freehold or leasehold. Check Local's area prices are built from these records.

Two things to know. A sale appears when it is registered, which can be weeks or months after completion, so the last month or two is always incomplete. And some kinds of sale are excluded from the standard figures. Price Paid Data is a record of completed sales, not a valuation of every home.

Scotland is different

Scotland's sales are registered by Registers of Scotland, and the record of individual sales isn't open data in the same way. Check Local shows Scottish prices as council-level figures from the UK House Price Index, labelled as such. You won't see street-level sales for a Scottish town, and its price is its council's, not the town's own.

Median, not mean

The mean (average) is pulled up by a few very expensive sales. The median is the middle sale: half sold for more and half for less. If 99 homes sell for about £250,000 and one sells for £3 million, the mean jumps by nearly £28,000 but the median barely moves. That's why Check Local leads with the median.

The mix of homes sold moves the figure

A median price changes when what sells changes, even if no home is worth any more. If a new block of flats completes, more cheap sales can pull an area's median down. A run of large detached sales pushes it up. Before reading a change as "prices rose", compare the same type of home, and see whether the number of sales of each type has shifted.

Year on year, over 12 months

Housing markets have seasons, so comparing one month with the month before mostly measures the season. Compare 12 months with the 12 months before. Check Local's headline prices cover the 12 months up to the most recent recorded sale, not up to today. That way a registration delay doesn't make the latest month look empty.

How many sales is enough?

A trend built on 20 sales a year can swing by a large percentage purely by chance: two expensive sales in one year and none the next. The fewer the sales, the less a change means. Always read the number of sales next to the price. For a small area, the council's trend is often a steadier guide, and Check Local says when an area's trend is mostly its council's.

To see these figures for a real place, open the property pages for Leeds or Cambridge, or compare two areas.