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How much does a house extension cost?

How much does a house extension cost?

House extensions can be a fantastic, practical way of adding more space to your home. While they’re most certainly a great option if you need more room in your home and don’t want to move, they’re also not a simple matter. Wrapping your head around all of the regulations and costs involved can be a challenge, so it’s always important to carefully consider everything you can before going into handling your extension. One of the most important aspects of that is evaluating the cost of your project.

How to determine the costs?

It goes without saying that costs of house extensions will vary heavily depending on a number of factors. The size and scope of your project is definitely an important one – a smaller extension will be cheaper, as will an extension of a room that doesn’t require any additional installations such as plumbing. Kitchens and bathrooms in extensions generally raise the price, as do multiple floors in a single extension. Aside from that, however, there’s always the matter of where you live. Extensions in London are bound to cost more than somewhere in the countryside.

Single-storey vs, two-storey extension

As a general rule, single-storey extensions are cheaper than double-storey ones. How much cheaper? Well, judging by a 2017 estimate, single-storey extensions cost between £1,200 and 1,500 per m sq. Of course, in areas like London, this price is higher, with £1,500 being the lowest price. No matter where you live, how much you’ll ultimately pay will depend on how big you want your extension. Now, as a general rule, a two-storey extension’s build costs will cost 50% more than a single-storey extension of the same floor area.

Kitchens and bathrooms

As can be expected, kitchen and bathroom extensions will cost more as you need extra materials, permissions, and workforce to take care of things like plumbing. Bathrooms are a bit more simple in this regard, with fewer installations needing to be implemented. Depending on the finish you want for it, add £5,000 to your bathroom costs compared to a regular extension – that should cover the additional expenses. As kitchens are a bit more complicated, that number goes up to £10,000 in those cases.

Other things to think about

There are various types of extensions, including much more complex procedures like basement and loft extensions. Should you consider those, be prepared to pay more as they require more careful planning and construction. Take windows into consideration when evaluating your costs, as their price tag may surprise you. Of course, the absolute most reliable way to determine the cost of your house extension is to get a quote from an expert!


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