How much do home extensions cost in 2019?
In a perfect world, money would be no object, but more often than not it is the price of a product that often dictates what home improvement projects go ahead and which ones don’t.
House extension costs can vary on the size of the extension, ranging from around £20,000 for a 4x3m extension, to £50,000 for one with 5x5m dimensions.
How much does an extension on a house cost? We’ve compiled a list of guide prices below, to help give you an idea on how much a typical house extension costs in the UK. It’s important to note that prices will inevitably vary between companies.
|Extension Width (mm)||Extension Projection (mm)||Guide Price|
|4000||3000||£23940 – £26460|
|4100||3000||£24538 – £27121|
|4200||3000||£25137 – £27783|
|4300||3000||£25735 – £28444|
|4400||3000||£26334 – £29106|
|4500||3000||£26932 – £29767|
|4600||3000||£27531 – £30429|
|4700||3000||£28129 – £31090|
|4800||3000||£28728 – £31752|
|4900||3000||£29326 – £32413|
|5000||3000||£29326 – £32413|
|5100||3000||£30523 – £33736|
|5200||3000||£31122 – £34398|
|5300||3000||£31720 – £35059|
|5400||3000||£32319 – £35721|
|5500||3000||£32917 – £36382|
|5600||3000||£33516 – £37044|
|5700||3000||£34114 – £37705|
|5800||3000||£34713 – £38367|
|5900||3000||£35311 – £39028|
|6000||3000||£35910 – £39690|
You will have to consider professional fees. An architect, planning application, building regulations or structural engineer can add on 10-15% to the overall home extension cost.
If your house extension includes a bathroom, it can add an additional £5000 to your overall cost – depending on your sanitary ware and finishes.
A kitchen can add £10,000 or more to the overall extension cost. If you are thrifty, a lower-mid range kitchen with appliances can cost anything up to £10,000.
A more top of the range kitchen and appliances will set you back slightly more.
Our guide price table for home extensions assume the costs for modest finishes and fittings such as electrics and lighting.
However, if you ware wanting higher-end finishes and joinery, the costs will inevitably increase.
Having double glazing? This can increase the cost also.
Sliding or bi-folding doors are also a popular additions to modern extensions at the moment.
You will need to factor in additional costs if any of the following apply:
If you are in the South East, you can expect to pay more than the rest of the UK. Notably more if you are based in London.
The price is often calculated per m2, with a typical price in London and the South East being around £1,600 and £2,1002 per square meter. So, depending on the dimensions you need, it could easily cost you around £50,000 for a 5m x 5m extensions.
Conservatories and house extensions can vary massively, or be very similar depending entirely on your specifications; such as materials and features.
For instance, a conservatory can be fully uPVC or can have dwarf walls with only the upper half of the structure being glass, and you can have house extensions either entirely made from brick or with its upper half similarly being made predominantly from glass.
So in short, house extensions are more brick than glass, whilst conservatories are more glass than brick. Orangeries are often a combination of the two.
Conservatories are far more affordable, costing only between £5,000 and £16,000 for a similar size of structure.
However, if you are looking for a more permanent extension then the extra cost for a brick extension is definitely worth it.
Conservatories are often very striking in their appearance, being highly recognisable thanks to their windows and uPVC structure, whilst a house extension can blend in flawlessly into the brickwork of the original property in order to create the illusion of a complete, unbroken continuation to the space.
As they more often than not lead into the back garden, both conservatories and extensions are often attached to the kitchen, allowing for more work room, or even a light and airy kitchen-diner. However, you can also use them as sun rooms, studies and even greenhouses (depending on how many windows you are having installed).
The price of both home improvement products can vary on a number of factors, often depending on the design specifications chosen by you for your bespoke extension.
These include: the size of the structure, what materials it is being made out of and what additional features you want attached.
For example, uPVC is both far quicker and easier to install than brick, as well as being more affordable and with a fraction of the building work and disruption caused by bricklaying.
uPVC for conservatories can often cut the installation time down from months to weeks, costing you much less in labour as well as materials.
Bricklaying, however, is far longer lasting and while uPVC can happily last for around 30 years with minimal upkeep, brick-built structures like extensions can last for almost as long as your pre-existing property does, with almost no attention whatsoever except for, perhaps, some additional insulation should you need it.
You no longer need planning permission to build house extensions in England. When is comes to the size of the structure, conservatories, orangeries and extensions are all now considered to be ‘permitted developments’ by the government, unless they exceed over a certain height and size.
This includes, not exceeding over half of the land around the original house (although this also depends on when the house was built, typically before or after 1948), no higher than the roof of the original property and a maximum of one storey.
So, it is still highly recommended that you familiarise yourself with the planning permission regulations, viewable on the UK government’s Planning Portal.
In a worst case scenario, failure to obtain planning permission when it is required can result in issues further on down the line of installation. This may result in an order to have it torn down.
A single-storey rear extension must not extend beyond the rear wall of a semi-detached home by more than 3 metres. For a detached house, it must not extend beyond 4 metres.
To avoid planning permission, the maximum height of a single-storey rear extension should be 4 metres.
Whilst many people use extensions as a way of adding space to a pre-existing room, such as a kitchen or an open plan living or dining room, they can also be used as an individual room in their own right.
If you have children in your home and would like them to have a safe and well lit space to play, then an extension or conservatory can be easily transformed into a great play-den that leads out into the garden, with wide windows that allow you to easily see where they are at all time to ensure you know that they are safe.
The space could also be used as a sunroom, allowing you to relax in the summer as well as all year round with our high quality and thermally efficient double glazing. It is a perfect place to entertain guests of an evening, offering views of your garden whilst protecting you from the elements and insects outside.
However, if you have some of our bespoke bi-folding doors attached, you can easily fold them back into a discreet singular panel to allow ease of access and an unobstructed way of bringing the outside in.
The multi-purpose room provided by an extension has endless possibilities when it comes to use, and can be used as anything from a living room, an art studio, a study or even a greenhouse. All of our extensions can also come with electric underfloor heating, allowing for use during the winter months as well as the summer, and can even have a water supply if you are considering having your kitchen extended into the structure.
If you would like to know more about the prospect of having an extension installed on your property, please feel free to take a look at our style guide or use our free online quotation engine to find yourself a competitive quote today.