Portman Square house price trends

The scatter plot below reveals the house price trend for Portman Square. The graph is constructed by plotting the price per square meter by date for all sales shows sales for only W1H 6L . The blue circles represent individual sales. You can touch or click on each blue dot to see more detail about the specific sales.

View data in table form

There are roughly 127 homes on Portman Square, we would have expected roughly 18 sales each year given that in the UK people sell their homes on average once every 7 years.
In the last 4 years there have been 13 property sales in Portman Square with 0 sold as new, averaging approximately 3 home sales per year . The average price per square metre (per square foot) in Portman Square, Marble Arch is £18,883 sqm (£1,754 per sq ft), this is from the Land Registry price paid of the 13 most recent sales.
The average size of all the properties on Portman Square is 102 m2 (1,097 sqft).