How much is your house worth per square metre – and how much value would an extension add?

Published by Hannah Nemeth on 12 October 2017.
Last updated on 12 October 2017

How much is your house worth per square metre – and how much value would an extension add?

Properties in the priciest area of England and Wales can cost 25 times as much as in the cheapest area, according to analysis of 2016 property prices.

For the first time, the Office for National Statistics (ONS) has analysed the cost of property prices in England and Wales by square metre – an area about the size of a red phone box – offering an interesting insight into the value of floor space.

Last year, the average cost of a property in England and Wales was £2,395 a square metre.

Unsurprisingly, 19 out of 20 of the most expensive properties per square metre were in London, with Kensington and Chelsea topping the list at £19,439.  This is followed by the City of London (£17,371) and City of Westminster (£16,246). In the capital, properties were valued, on average, at £6,639 per square metre last year.

In contrast, South Wales and Lancashire are the cheapest places to buy a home. Homeowners in Blaenau Gwent in South Wales, enjoyed the same amount of space for just £777, with Merthyr Tydfil, Neath Port Talbot, Burnley and Hyndburn all having properties averaging at less than £1,000 per square metre.

Commenting on the data, Andy Sommerville, director at online search business Search Acumen, says it highlights how unaffordable property prices have become.

He says: “Today’s figures crudely highlight the extent of the affordability crisis that is hindering the dream of home ownership for millions. To put today’s figures into context, the average price per room in the UK is £57,065, double the average UK annual salary.”

Russell Quirk, chief executive of online agent eMoov.co.uk, agrees that London prices per square metre are “astounding”, but says it’s not all bad.

 “Of course, it is no surprise that an over-inflated London market leads the way in terms of highest price, despite a slowdown in price growth in recent times. £2,305 a square metre is a high price to pay to get on the UK ladder, but this research also shows that across England and Wales there are many far more affordable options,” he says.

Flats have just got bigger

The ONS also reveals that new-build flats in England and Wales have got 18% bigger in the past three years, while new-build houses have remained around the same size.

Mr Quirk adds: “This data highlights a shift in the way we are living, with flats increasing in size as many adapt to this more affordable property type, with city living remaining a popular choice.”

The value of an extension

The ONS data on property prices per square metre has also been used to create a tool, so homeowners can get an idea of how much extra floor space could be worth different areas of England and Wales, while bearing in mind that an extension’s value would also depend on its design and quality of construction as well as the property’s exact location.

For example, a small extension measuring 15 sq m in Blaenau Gwent would add £11,625 to the value of a property, while the same extra space in Kensington and Chelsea would inject an extra £269,820 into a property’s value. You can try out the ONS’ extension tool below:

The ONS says that, on average, a 15 sq m extension in England and Wales would add £35,445 in value, while a medium (25sq m) extension would add £59,075 and a large (35 sq m) extension put an extra £82,705 on to a property’s value.

But before you get the builders in, Mr Quirk warns: “It’s important to remember that the cost of an extension won't always translate into the same monetary value for the property as a whole.

“In a major city where space is tight, a loft extension can add real value, but outside of the city where there is an abundance of space, this isn't always the case."  

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