House extensions Costs

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Average House extensions cost

The regular cost of House extensions are £55,929 in your area. Costs vary based upon the materials and the company picked. The upper price range can be as high as £82,929. The material costs are in most cases around£10,500.

Average price per House extensions job in 2025

Avg. price low

Avg. price low
£30,358

Avg. price

Avg. price
£55,929

Avg. price high

Avg. price high
£82,929

£83500

£62625

£41750

£20875

£0

Prices based on actual House extensions costs for your area, as reported by local LeadsDoWork members.

House extensions installation cost in your area 2025

Labour cost £27,000
Material cost £10,500
Waste removal £2,500
Time frame: 10-14 weeks

Advantages for House extensions

  • Create additional usable space within in your home
  • Create more room upstairs, additional bathroom or bedrooms
  • Increases the value of your home
  • As your family grows it means you can stay in the same home for longer

Disadvantages for House extensions

  • Will cause a lot of disruption when the existing house wall is opened up into the extension
  • Upstairs windows should be carefully planned not to look into neighbours homes

House extensions Manufacturers

House extensions FAQs

How to finance a house extension?

Do you want to beautify and increase the value of your home? If yes, a refurb and house extension is definitely a great option to consider. Depending on your home extension project, the value that’ll be added to your home’s resale value varies. However, the cost of completing a house extension project can be huge, so you just might want to consider your financing options. Fortunately, there are various options through which your house extension project can be funded with each having its own pros and cons. Your specific circumstances will determine the one that’s going to work best for you, so let’s take a look at some of the best options to help you fund your project.

• Home Remortgaging

The process whereby a mortgage is transferred from one provider to the other is known as remortgaging. This is usually done to generate funds for a project by entering a more lengthy repayment term commitment when switching. If you want to raise your funds in a quick manner, this process works best.

• Savings

This is a good reason to cultivate a good saving habits. If you’ve been able to save up some mega bucks then you’d probably won’t have to borrow money to finance your house extension.

• Unsecured Loans

If you do not buy into the idea of borrowing more against your property, you may just be able to apply for an unsecured loan especially if you have a good credit record. A secured loan makes use of collaterals like a car or house to serve as a cover for the lender, meanwhile an unsecured loan is based mainly on the credit managing history of the borrower.

• Credit Card

There are some great benefits that comes with financing your small or medium scale extension project with your credit card. Not only does it offer some real lifeline if problems arise during the project, but you can also avoid paying excessive interest on the investment by ensuring your deal has a 0% introductory rate.

Are house extensions worth it?

Often referred to by many as the holy grail of home improvements, house extension comes with a wide range of benefits which makes it easy to see why the extension could be a great uptick in the potential price of your property in terms of sales. So if you’re looking to build a new home extension but still not convinced about the project, we’re here to help you. Being fully aware any home construction work is usually a heavy investment, there’s a huge need to be set on your decision before scheduling the commencement of any work. So are house extensions worth it? Below are some of the top benefits offered by house extensions to help you decide if it’s the most suitable route for you.

• Add To Your Home’s Value

Building an home extension is a great way to add value to your home before selling. Increasing the living space of your home is an incredible appeal to many buyers which significantly increases your property’s total value. However, you must ensure that the extension is impressively designed using top quality materials in order to generate more value.

• Good Alternative To House Moving

The most common reason for moving is usually due to a lack of sufficient space, but with house prices steadily on the increase a cost effective alternative is highly sought after. This alternative is house extension which creates more space for the household to spread out and have more privacy.

• You May Not Require A Planning Permission

You can extend your house and still not need to apply for a planning permission. To achieve this, simply comply with the laid down rules set under the permitted development rights.

• Extra Living Space

If you fill you’re starting to outgrow your existing structure and do not buy into the idea of moving, then your best bet might just be to extend your home.

How much does a two storey house extension cost?

If you’re considering adding a two storey house extension, then setting a budget for this project would be a great way to get started. Similar to a rear extension, a two storey extension usually leaves the rest of the building needing some work and, due to its size, this may imply the re-development of the entire house - which is why they can be very costly. Some of the other influencing factors that can have big impact on a two storey house extension cost includes: your location, the size of the build, complexity of the design ( anything beyond the standard build will normally require more expertise and time), the glazing to be incorporated ( the more the glass used in the project, the more the material cost), as well as the team used.

Generally, when it comes to extensions, the major part of the expenses will be made on the build of the project. This is because it doesn’t only cover the material cost but also the contractor’s overhead as well as the daily rates. At this stage, the extension prices can be determined by the standard of the work that’s being done.

For a fairly average room size of about 18 square metre, the two storey extension should cost within the range of £2,500 to £3,000 per square metre - with the range being determined by the finishes incorporated. Therefore, a two storey extension of about 18 square metre should cost within the range of £45,000 to £55,000. However, this is with the assumption that there are standard window sizes, bathroom suits are modest, and without any need for any purpose joinery or glazing. If you wish to include all these extra features you’ll also have to pay more to make the total cost between £70,000 to £80,000.

Do I need my neighbours’ permission for an extension?

Well the reality is, sometimes, neighbours just don’t get along. With several individuals living in close proximity, it’s little surprise they tend to get on one another’s nerves from time to time. However, there’s a difference between having a tiff and being able to transform your house the way you want without having to obtain your neighbour’s approval.

The short and simple answer to this question is, not necessarily. However, you must first educate yourself by thinking about your extension and how it affects the houses around you. We’d strongly recommend you talk proposals through with your neighbour so as to avoid possible conflicts later. There are a number of reasons why your neighbour can protest to your new home extension plans. Let’s take a look!

 

  • In the event whereby your new extension is blocking their view or providing an unwanted shade on their property. Here, they have a legitimate reason to protest as no one would want their once sunny garden suddenly covered or plummet into shade.
  • In the event where it leads to a loss of privacy. For instance, if your new extension possesses a window which overlooks the neighbour’s property in any way. This is likely to be taken as an invasion of privacy and that has a little to no chance of being a welcomed idea.
  • If it’s a major project and going to take a lot of weeks before completion. The noise generated, especially when your neighbours are enjoying your summer holidays or weekends, can make their gardens not as relaxing as it used to be.
Should I use concrete or timber footings?

For 2 metre solid fences it’s recommended to use concrete posts to support each panel. For smaller 1 metre fences or for picket fences with gaps between each timber piece you can use timber posts. A fencing contractor will be able to advise you on the best materials from the length and requirements of a new fence.

Where to start with a house extension?

Have you decided to improve your property instead of moving? The common problem most homeowners face after deciding to embark on a home extension project is not knowing where to start. In this article we’ll walk you through everything you need to consider and put in place before commencement of your home extension project.

• Is the extension worth it?

Before breaking the bank, you must be sure that the project will add good value to your home. In terms of “value, this is not only limited to the financial gain after disposal of the property, but also several other juicy benefits to be derived from extending your home like an extra living space for the household to spread out and more.

• Do you need a planning permission?

Check with your local authority to determine whether or not you’ll require to submit an application. You can also consult a building expert like an architect for advice.

• What are the building regulation?

Even though planning permission can be dodged, you can not avoid building regulations. These regulations are the set national minimum standards for construction and design which you must comply with to ensure the safety of the individuals in and around it.

• Who will design the extension?

You have to decided whether you’ll hire a professional architect to design the extension or not.

• Who will manage the building work?

If your home extension project is designed and built by a professional company, they’ll be responsible for the management. However, if you decide to use an architect or designed it yourself, you’ll have to hire a main contractor to manage the build.

• How to set the budget?

There are so many factors that can affect the cost of an extension, so it’s better to get the costs from your builder before proceeding.

• Do I need yo inform my home insurance firm?

Absolutely! This is very important as the new extension may affect the rebuilding cost of your property which could have an impact on the policy premium.

• Do I need to inform my neighbours?

It’s very important to discuss your plan with your neighbours before applying for a planning permission and communicate about the concerns they might have.

How much value does an extension add to your house?

Are you interested in extending your home to create more living space? If yes, then you’d probably want to know how much value it can add to your property in order to compare the building costs to the potential value gain. Well, as long as you know what you’re doing, your house doesn’t necessarily have to be a money pit. So what are your options when talking about home extensions and what’s the associated value to be gained?

• Bathroom Extensions

Although you should have it in mind that bathroom extensions isn’t usually that cheap, but once done, it can increase the value of a standard UK house within the range of £12,000 to £15,000. Meanwhile the finishing cost of a bathroom can range from £2,500 to £7,000.

• Single or Double Storey Extensions

Single storey extensions are always huge when it comes to increasing the value of your home - giving about 4 to 7 percent increase. If it goes that far, then literally nothing beats a full spectrum, double storey extension which can give up to 11 percent increase in the value of a property - equalling about a whooping £33,000 for a standard home in the UK.

• Conservatory Extension

With conservatories becoming more and more popular in the UK due to the weather conditions, several buyers are now including it’s availability as part of the criteria for purchasing a house. Wonder why? This is simply because everyone wants to enjoy their garden all throughout the year. As a result of this high demand, adding this type of extension to your house can go a long way to increase it’s value. However, it’s very important to incorporate high quality materials during construction. With glass conservatories offering, on the average, up to £5,000 increase in value, the cheaper PVC alternative offers much less value and can also deter potential buyers.

How much is a double house extension?

A double house extension is basically a construction to any aspect of your house that elevates up to offer two floors of space. It can be structured to suit your existing home in two storeys or as a side wing on a taller property. If you’re considering building a double house extension, then estimating the cost is a very important task to do before commencing the project. In this article, we’ll give you an idea of the cost of a double house extension so you can estimate yours accordingly.

The double house extension cost depends on several factors that’s specific to your home as well as your design choice. These includes:

• Location of your property. Places like London and the southeast will generally cost more than the other regions due to higher demands.

• Accessibility of the site. The ease of your site’s accessibility also plays a key role in the price.

• Size of the extension. The more the extension’s size in footprint and square metres, the higher the possible costs.

• Materials used in making the roof as well as the complexity of the roof design.

• Your choice of finishing. These includes flooring window and door frames, glazing, underfloor heating and roof lights.

• Your property’s soil type. Different types of soil requires varying treatments as well as materials to develop solid foundations.

Constructing a double house extension is a quite simple build in terms of technicality when its to the side or rear of your house as this can also help you save some money. Generally, considerably expanding your home’s space by building a double house extension will cost within the range of £1,500 per m2 to about £2,800 per m2.

PROJECT ADVICE | 10 ways to cut the cost of your extension | Future Homes Network

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