He was responding to the Hometrack UK Cities House Price Index, which revealed that house prices in Edinburgh, Glasgow, Southampton, Bristol and Birmingham have outpaced London in the three months to November.
Duncombe said: “Although homeowners in these areas might be pleased to see their homes increase in value, rapid house price growth is not a good thing.
“In London there have long been concerns about people being priced out of the housing market due to unsustainable price rises.
“If the growth trends we have seen in the capital are repeated in other parts of the country, decreasing affordability could start to become an issue across the UK.”
London’s house growth stood at 0.5% in the last quarter, with Edinburgh (1.8%) and Glasgow (0.9%) leading the way.
Duncombe added: “For a healthy housing market, prices should increase at a similar rate to inflation.
“A major factor driving prices higher is the chronic lack of supply of suitable homes.
“Building more houses helps to ensure that supply and demand are more in line with each other, keeping prices lower and therefore allowing more people to buy a home.”
