How Much Do Extensions Cost in 2019?

Extension prices are often dependent on the size of the structure you are having installed, and are typically estimated around £1,000 per meter for a single storey, or £1,600 for two storeys. This means that a 4x3m extensions can cost between £23,000 and £26,000, whilst a 5x5m extension can set you back around £50,000.

This may seem like a lot, but extensions don’t just add space to your home, they can also add value and desirability to your property, making it more likely to sell for a higher price should you ever put it on the market. Because of its mainly brick-built structure, extensions can last for as long as the rest of your property, with very minimal upkeep and blending in seamlessly into the masonry of your pre-existing home.

House Extension Costs

All that being said, what is the cost of your desired house extension going to be? We’ve put together a helpful table of guide prices so you can get the best idea possible about how your extension is going to affect your home improvement budget. It’s important to keep in mind that these prices can and will vary somewhat 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

Get Instant Guide Prices and Quotes For Extensions

With these prices in mind, you may want to start thinking about how it compares to other similar house extension options, such as conservatories and orangeries. But what exactly is the difference, and how will it affect your property?

What is the Difference Between a Conservatory, an Orangery and a House Extension?

House extension options can vary from wildly different beasts to very similar in appearance, all depending on what materials, designs and roofing materials you choose from. However, there are a few noticeable differences between the three different types.


Conservatories are predominantly constructed from uPVC, with more glass than brickwork in its structure. They can come with either floor to ceiling windows, allowing for an unobstructed view of your garden or outside area, or with dwarf walls that allow for superior insulation, plumbing and electrical wiring.

These walls act as any other kind of wall, able to be painted, drilled and fitted with a numerous amount of personalisation options to really make it your own. Double glazed units can also be fitted with pelmets to improve insulation, prevent heat loss through convection currents, and allow for light fittings, speakers and other fittings to be installed.




Orangeries are the best of both worlds when it comes to conservatories and house extensions. They can be smaller than your typical house extension, and because of this share with a conservatory an exemption from planning permission; and whilst they are more affordable, they still sport an extensions’ superior insulation, security and privacy, and blend in well with the pre-existing brickwork of your property.

Originating in the 17th century as a way to house citrus plants during the winter months, they bring sense of class and sophistication to a property, with ornate detailing and stunning features to make it stand out from the crowd.

Double Glazing Prices


Extensions are, like orangeries, predominantly built from brick rather than uPVC, but can still have ample lighting from windows, skylights and uPVC roofing options. Whilst both conservatories and orangeries are limited in size in order to avoid planning permission requirements, extensions are pretty much unconfined and can be made to much larger dimensions.

This does require planning permission, but once you are through that initial planning stage then it is easy enough to have installed quickly and efficiently.

While many homeowners use extensions as a way of expanding on a pre-existing room, such as kitchens, living areas and dining rooms, extensions can be a completely separate room entirely, or incorporated into a larger communal space.

Perhaps you want a studio or office space for working from home, maybe you want a safe and well-lit playroom for your children, or maybe you just want a nice place to relax of an evening.

Because of its brick walls, there is no difficulty in having wiring and plumbing installed in the walls and allowing for kitchen expansion and other uses, even if it is just to fill up a watering can for your plants.

Because of their size and materials, home extensions are not cheap. However, they are a great investment and if you are in dire need of extra space in your home, they are much more affordable than moving home.




Home Extension Options

Extensions can come in either one or two storeys, depending on the size of your property, and, as mentioned above, an extension typically costs £1,000 per meter, with £1,600+ for two storeys. However,  by keeping your extension to a ground-floor development, then you can pretty much halve the cost from £100,000 to £50,000.

Simple designs may be more affordable, but they are in no way lesser to more complex styles, and in many ways an understated design can help accentuate your properties pre-existing features.

Knowing the price ahead of time can be vitally important to keeping within your budget, and because of this it is very important that you are 100% satisfied with your initially planned out design, as changes can often put you out of pocket. Also, whilst made-to-order may seem tempting, off-the-shelf features are far more affordable and are often just as good.

Rather than having an extension constructed on-site, having a pre-fabricated conservatory assembled from pieces put together during manufacturing can often result in an installation 10-25% cheaper than traditional on-site construction.

There are several steps when having an extension installed, from initial planning stages to site surveys to actual construction work, and each of them has its own estimated price. Planning application fees have gone up in recent years, so the design work you do there is vitally important to remaining within the budget you set out for yourself. As mentioned above, prices of materials and features can vary depending on whether they are off-the-shelf or bespoke, and a change of material can affect your price by hundreds of pounds.

House Extension Cost Calculator

In order for you to get the best ideas about what kind of home extension is right for your property, we have put together a quotation engine for you to build up your very own bespoke extension design from scratch, choosing from a variety of personalization options including sizes, colours, materials and additional features. To do this use our extension cost calculator for a free online quotation.

So, no matter what you want your extension for or what your budget it, if you have your heart set on getting a professional and efficient extension installed on your property, Double Glazing on the Web can provide you with all of the information you need to know.

If you want to know more information about the price of extensions, or simply want to speak to someone from our team about our service, feel free to contact us through our online contact form.