London house prices have underperformed much of the rest of the market for more than a decade now. The UK as a whole has seen house prices rise by 47 per cent from £184,000 to £270,000 during that time. In inner London (the 13 most central boroughs and the City of London) , the average terraced house costs £876,000. Meanwhile detached house prices range from £400,000 to several million in the more affluent areas of the city and surrounding areas. 'The average property price in inner and outer London was approximately £640,000 last month,' Mary-Lou Press, President of NAEA Propertymark.