If you’ve been thinking about extending your home, you might have asked the question, what is the cheapest way to extend a house? When you desperately need more space in your home, there are several ways to expand your house, and each comes at a different price point. In this post, we’ll show you some general costs of different types of extensions so that you can figure out what is within your budget. 

How much does an extension cost?

In general, an extension project costs between £1350 and £2250 per m². To put that into perspective, a 30m² kitchen extension will cost between £40,500 and £67,500.  The reason the cost varies so widely is that there are many factors that affect the price of an extension, including:
  • How many storeys you want to build. 
  • The size and shape of the extension. 
  • The quality of the build. 
  • The materials you use. 
  • The amount of glazing your incorporate. 
  • Whether you include a kitchen or bathroom. 
There are many costs that need to be factored in when costing an extension project. These include:
  • Architect fees (around 7% of the construction cost)
  • A structural engineer (£500-£1,250) 
  • Survey fees (between £700-£1,800)
  • Planning permission, if needed (around £200).
  • Lawful Development Certificate (currently £103)
  • Party Wall Agreement, if needed (around £1,000 per affected neighbour).

How Much Does a Single Storey Extension Cost?

A box-shaped, single-storey extension will cost between £1,350 and £1,750/m². That means an 8x4m kitchen extension will cost between £54,400 and £56,000. Remember, costs quickly rise if you’re incorporating a kitchen or bathroom because of the additional plumbing work involved. 

How Much Does a Double Storey Extension Cost?

A double-storey extension actually works out at roughly the same price as a single-storey. Expect to pay between £1250 and £1650 per m². Many people believe double-storey extensions are significantly more expensive, but in reality, you’re only adding more walls and floor joists. The expensive part of any extension is the foundations. 

How Much Does a Side Extension Cost?

The cost of a side extension largely depends on the size. Smaller extensions tend to be more expensive than larger ones because they are more difficult to complete.  In general, a side extension will cost between £1500 and £2000 per m².  The cost of your side extension idea depends largely on the size of the structure, the location of the build and the quality of the materials and finishes. 

What’s the cheapest way to extend a house?

In general, the cheapest way to extend a house is a square or rectangular footprint with a simple pitched roof. You’ll also pay significantly less if the extension doesn’t include a bathroom or a new kitchen.  The simpler the design of the extension, the cheaper it will be. This means forgoing additional glazing, bi-fold doors, or other design elements that will increase the bottom line. 

Get a free quote for your house extension

If you’re curious about what a home extension would cost for your property, we have a full price page giving you some examples of extensions and their prices. You can also get in touch with us to arrange a free pricing consultation. We’ll assess your property and give you a free, no-obligation quote for your new extension.