Analysis of London housing sales data

The Land Registry has recently started publishing data on individual residential property sales, and the two charts below use the data to compare housing markets in London and the rest of England and Wales.

The first chart shows the distribution of prices (up to £1m) in the capital and elsewhere in 2012, broken down by the tenure type (leasehold and freehold, roughly corresponding to flats and houses) and whether or not the property was newly built at the time of sale. Average prices are higher in London across all categories. You can also see the effects of stamp duty in the kinks of the price distribution curves just before the threshold values of £125,000, £250,000 and £500,000.

House price distributions, London and the rest of England and Wales, 2012


The second chart plots the total value of new build and non-new build residential property sales in 2012 by local authority area, with London boroughs in cyan and other local authorities in pink. In the vast majority of cases the value of new build sales is far lower than the value of older home sales. London boroughs account for the top four new build markets, Tower Hamlets (in the top left) leading the way with new build sales that account for around 30% of total sales value in 2012. Kensington and Chelsea (bottom right) is at the other end of the spectrum, with very few new build sales (because it doesn’t really build any new housing) but an incredibly valuable resale market. Westminster (top right) combines both a lot of resale and lot of new build sales.

Total value of new and old housing sales by local authority, 2012


The data was analysed in R and the charts produced using the ggplot2 package among others.


London Housing Market Report

I have converted the GLA’s London Housing Market Report from a quarterly document (last edition here) to a live resource on the London Datastore. It uses the Google Charts service via the googlevis R package, which allows you to create HTML straight from your own data rather than having to upload it to Google’s servers. While the use of Google Charts started out as a labour-saving device and hopefully will be over time, setting this up involved a lot of fiddling with Javascript to get the charts to display okay on the Datastore’s Drupal system. I’m grateful to Scott Day in the GLA’s GIS team for help with this aspect.

The great advantage of using Google Charts are that its layout and colour defaults are very good and where changes are required they are pretty easy to implement. I used to agonise excessively over the choice of colours in charts like this one but I think the Google version looks fine.

Quarterly change in average London house prices - comparison of indices

Most of the report consists of fairly standard presentations of market data. But one thing I would like to draw people’s attention to is the presentation of changes in average rents as published by the Valuation Office Agency. We show these changes at Inner London, Outer London and London-wide level to show that the London figure can be significantly distorted by shifts in the VOA dataset, notably the exclusion of a large number of Housing Benefit cases in Outer London over the last year which has skewed the balance of the dataset towards Inner London. So the average rent for a one bedroom property in London seems to have risen 13% even though the average in Inner London rose by 8% and the average in Outer London by ‘only’ 6%! I’m not sure these features of the VOA dataset are widely understood but lots of people are using their data to calculate changes anyway.

Change in median private rents in London, March 2012 to March 2013