You’re probably aware of the benefits an extension can bring to your home, but how much is one actually worth? How much will it add to the value of your property? Wouldn’t it be worth knowing before you contemplated building one?

A very useful guide has been delivered by the Office for National Statistics (ONS), a calculator that can estimate the average cost of a property per square metre in each local authority in England and Wales. You can find it here at

The calculator estimates that extension builders in Oxford could build you a small size extension (15 square metres) that could be worth £69,855, while a large extension (35 square metres) could add £162,995.

The exact figure depends on the quality of construction and whether you live in central Oxford or on the outskirts where space is more abundant. So, in town where space is at a premium, a loft extension can add real value, but not so much for a property outside of the city.

More specifically, value added is dependent on the type of extension. The Nationwide Building Society researched the value of improvements to an average three-bedroom house. They found an extension creating a double bedroom and en-suite can add up to 23% to the value of your property. An extra bathroom could add up to 6% and an additional double bedroom, 12%.

In a survey of 1000 home-improvers, money-lending outfit Zopa found that an average extension cost was £19,750. The average return on investment for an extension was 71% and the average amount of profit generated by an extension, £14,000.

If you’re looking to the future and selling, consider the buyer. An improvement that may add value in one area may not necessarily add value elsewhere. A family-sized home would benefit more from extra bathrooms and large kitchens, for instance, while a garage could add more value to a property in central Oxford.

Oxford extension builders will be able to best advise on how to match your extension to the local architectural style, how it will connect with the house and how it will affect the layout.

You can always contact us here at Regal Homemaker. As one of the most experienced and trusted extension builders in Oxford, we can advise on the best and most cost-effective way of extending your home. Adding most value while getting the most out of your budget.