House extensions Costs

Compare House Extension Prices Near You

Home > Extensions & Conversions Projects > House extensions

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

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.

What types of extension are there?

There are many different types of extension. For example, you could install an orangery, flat or pitched roof extension, over-structure extension, single or double storey extension or a glass box extension. Which one of these is most suitable will depend on your existing property.

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.

Will my extension be expensive?

It depends on the size and type of extension. Small porches or flat roof extensions are very reasonably priced. More substantial two storey extensions can be expensive. In general, the price is roughly proportional to the amount of space you add to 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.

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 big can my house extension be?

The holy grail of home extensions is basically the need for additional space for living as well as leisure. However, before commencing your home extension project, you’d probably want to know just how big your new building can be. In this article, you’ll find the answer to this question which is also frequently asked by many other home or property owners in the UK.

Besides your budget, there are two other major influencing factors that can determine just how much extra room that can be added. These factors include whether you wish to carry out the extension project under Permitted Development rights which is usually for a smaller project or you’d prefer to opt for a larger project which is covered by Planning Permission.

Apart from the limitations in the size of an extension under Permitted Development, the extensions are also a lot more affordable and consumes less time when compared to the extensions under planning permission. So what exactly is the size limit for an extension under Permitted Development and the ones under Planning Permission?

For a single storey extension, the maximum size that can be constructed without having to submit an application for Planning Permission includes:

• An extension should have a maximum length of 6m, if you reside in a terraced home or a semi-detached property.

• Extensions for detached properties can have a maximum length of 8m.

• The extension built must not go beyond half your garden’s area.

• The extension should have a maximum height of 4 metres, but in the event whereby the extension is situated within 2 metres of the boundary of your property, it should not exceed a height of 3 metres.

• The extension should not be higher than the highest part of the existing house’s roof.

Can an extension add value to my home?

Yes. Most extensions will add substantial value to your home, and you may find that the extension adds more value than it cost. However, it’s important to be sure that the home remains balanced. Extending your garage and leaving your property with no parking spaces, for example, may impact your ability to sell.

Our reviews

Average

Would highly recommend

Would highly recommend, they found me a firm which I was happy with a quote they give me and went ahead and had my job done within 2 days of enquiring.

Good easy way to find a selection of…

Good easy way to find a selection of trades you need all in one place.

Love LeadsDoWork it's a big part of my …

Love LeadsDoWork it's a big part of my Business I would recommend to anyone

Dream the Build

Based: in London, EC1V

DREAM the Build. Ltd ' Constructing your Vision

Making home development exciting, fun and asse...

Latest review

Jagdish K., HA3
4th October 2016

House Extensions in Harrow

In dept details for quotation great approach. Great advice Still going through the qu...

Jassi Builders

Based: in Hayes, UB4

Hi Jassi Builders LTD here, I am a specialist in planning, designing and building control services. ...

Latest review

Julian F., HP2
25th February 2022

House Extensions in Hemel Hempstead

No quote received

B&G Carpentry

Based: in Newhaven, BN9

B&G Carpentry is based in Newhaven and have 5 positive reviews

Latest review

Laurie S., BN12
24th February 2020

House Extensions in Worthing

Hi Bob, I'm very pleased with my new porch. Having phoned me immediately when I cont...

Castell Home Improvements

Based: in Walton-on-thames, KT12

Castell Home Improvements is based in Walton-on-thames and have 2 positive reviews

Latest review

Pravin S., SM5
25th January 2018

House Extensions in Carshalton

Not had any discussion one Cost so far

OJS Building

Based: in Surrey, KT17

OJS Building are a local building firm based in Epsom and offering services to domestic and commerci...

Latest review

Abby E., BN7
14th July 2017

House Extensions in Lewes

Quick home visit and quote

Omega Lifestyle

Based: in Peterborough, PE7

Omega Lifestyle prides itself on providing a high quality of customer service from the initial order...

Latest review

J D., PE32
17th October 2016

House Extensions in King's Lynn

I was so pleased to finally meet a tradesman who actually provided a quote and so qui...

MTL Contractors

Based: in Southampton, SO14

MTL Contractors is based in Southampton and have 2 positive reviews

Latest review

David M., SP10
14th December 2016

House Extensions in Andover

Awaiting quote but service so far has been very good.

Nicholas James Construction

Based: in Bromley, BR1

From past fifteen years we have been established as the finest building and construction service pro...

Latest review

Jagdish K., HA3
4th October 2016

House Extensions in Harrow

Absolutely pleasant appointment. Very patient and polite, listened carefully to detai...

Scotbuild Group

Based: in Fife, KY14

Scotbuild Group is based in Fife and have 7 positive reviews

Latest review

Lesley D., DD4
3rd October 2016

House Extensions in Dundee

I cannot comment on prices as we are not yet at that stage

Options Home Improvements

Based: in Kent, ME8

Here at Options Home Improvements we specialize is the bespoke design & installation of PVCu & Alumi...

Latest review

Lisa V., ME1
7th August 2016

House Extensions in Rochester

I haven't had the extension built yet but am planning to use them

Rated Local builders

Jassi Builders LTD

2 review(s)
Based: in Hayes, UB4 9YD

Hi Jassi Builders LTD here, I am a specialist in planning, designing and building control services. I make sure that I have completed all my work on perfect time and leave customers in complete satisfaction. We do all types of loft conversions, exten...

Dream the Build

19 review(s)
Based: in London, EC1V 2NX

DREAM the Build. Ltd ' Constructing your Vision Making home development exciting, fun and asset building experience , future proofing household & investors Who we are ? Starting fresh in a new country is never easy, but what we did Catal...

Options Home Improvements LTD

1 review(s)
Based: in Kent, ME8 0DB

Here at Options Home Improvements we specialize is the bespoke design & installation of PVCu & Aluminium, windows and doors, orangeries & conservatories in Gillingham, Kent & South East area. Options Home Improvements was started due to the seemi...

Blue SKY Developers Limited

1 review(s)
Based: in London, NW3 6DX

Blue Sky Developers is a registered company in the UK that specialises in all building services you could require. We are based in North London but carry work out all around London.

Scotbuild Group LTD

7 review(s)
Based: in Fife, KY14 7AU

Scotbuild Group LTD based in Fife, offer services in Extensions & Conversions. They have an average rating of 4.5471428571429 from 7 review(s). See their latest 5 star review below

Build Junky

3 review(s)
Based: in Doncaster, DN9 1AL

We are a high quality building company based on the outskirts of Doncaster. With an aim to produce consistent workmanship of the highest standard alongside giving our customers the very best service available. Alongside carrying ou...

CMK Home Extensions LTD

2 review(s)
Based: in Glasgow, G61 3NU

The alternative to traditional domestic builders CMK Home Extensions bring a modern, professional approach to all your home improvement and extension needs. Whether its a new open plan living space, kitchen diner, family room or sun room we can trans...

Nicholas James Construction

7 review(s)
Based: in Bromley, BR1 3AX

From past fifteen years we have been established as the finest building and construction service provider to clients in Bromley and its surrounding areas.

Magnus Technical Engineering LTD

6 review(s)
Based: in Appley bridge, WN6 9DB

Magnus Technical Engineering LTD based in Appley bridge, offer services in Extensions & Conversions. They have an average rating of 4.9583333333333 from 6 review(s). See their latest 5 star review below

Tectra Partnership Ltd

1 review(s)
Based: in Slough, SL3 0JE

Tectra Partnership Ltd based in Slough, offer services in Extensions & Conversions. They have an average rating of 4.75 from 1 review(s). See their latest 5 star review below

Similar Customer Enquiries for House extensions

10 Jun

House Extensions

Andover - SP10

Enquiry from: John S

Start Date: 1 to 3 months

customer in andover areas is looking to do a couple of projects at the moment, and would like quotes for house extension.confirmed interest via telephone, sms and email at 10/06/2025 10:13.please call...

Post a similar request >

09 Jun

House Extensions

Gloucester - GL3

Enquiry from: Amina A

Start Date: Immediate

customer in areas is looking to do a couple of projects at the moment, and would like quotes for house extension.confirmed interest via sms and email at 09/06/2025 21:28.please call to arrange appoin...

Post a similar request >

03 Jun

House Extensions

Middlesbrough - TS7

Enquiry from: Aicha S

Start Date: Immediate

customer made an online enquiry for house extension and confirmed on sms and email they would like a call with a builder to discuss prices.please call to arrange an appointment to quote. are you the p...

Post a similar request >

31 May

House Extensions

Coventry - CV3

Enquiry from: Prashanth P

Start Date: Immediate

Customer made an online enquiry for House Extension via one of our websites. Confirmed via email/SMS/. Please call to arrange an appointment to quote.

Post a similar request >

31 May

House Extensions

Manchester - M23

Enquiry from: Akhil P

Start Date: Immediate

customer requested quotes for house extension from a builder around manchester. they are considering a couple of projects at the moment.call anytime to arrange appointment to discuss. the information ...

Post a similar request >

28 May

House Extensions

Airdrie - ML6

Enquiry from: Muhydeen A

Start Date: Immediate

customer has a extensions & conversions project they are looking to have done, specially they want quotes for house extension. they are unsure of options so would like to discuss with a builder.confir...

Post a similar request >

26 May

House Extensions

Perth - PH1

Enquiry from: Oluchi A

Start Date: Immediate

Single storey house extension

Post a similar request >

16 May

House Extensions

Salisbury - SP2

Enquiry from: Zlati D

Start Date: Immediate

customer made enquiry for house extension quotes online. homeowner lives in salisbury area. please call to arrange appointment are you the property owner: relative of owner looking for: single storey ...

Post a similar request >

14 May

House Extensions

Nottingham - NG9

Enquiry from: Nicola L

Start Date: Immediate

What type of extension do you need? Single storey extension When was the property built? 1921 to 1979 How many stories is the current building? 2 Storeys Do you have plans drawn up? Yes - I have pl...

Post a similar request >

14 May

House Extensions

Nottingham - NG5

Enquiry from: Lucy H

Start Date: Immediate

What type of extension do you need? Two storey extension When was the property built? 1921 to 1979 How many stories is the current building? 2 Storeys Do you have plans drawn up? Yes - I have plans...

Post a similar request >

14 May

House Extensions

Silverburn - EH26

Enquiry from: Liza M

Start Date: Immediate

What type of extension do you need? Single storey extension When was the property built? 1980 or later How many stories is the current building? 2 Storeys What project do you need? House Extensi...

Post a similar request >

14 May

House Extensions

Rugby - CV22

Enquiry from: Catherine S

Start Date: Immediate

Customer made an online enquiry for House Extension via one of our websites. Confirmed via . Please call to arrange an appointment to quote.

Post a similar request >

12 May

House Extensions

Pinner - HA5

Enquiry from: Mohamed H

Start Date: Immediate

customer has a extensions & conversions project they are looking to have done, specially they want quotes for house extension. they are unsure of options so would like to discuss with a builder.confir...

Post a similar request >

12 May

House Extensions

Dukinfield - SK16

Enquiry from: Salma G

Start Date: Immediate

what type of extension do you need? two storey extension when was the property built? 1921 to 1979 how many stories is the current building? 2 storeys do you have plans drawn up? yes - i have plans wh...

Post a similar request >

08 May

House Extensions

Glasgow - G68

Enquiry from: S

Start Date: Immediate

What type of property is this for? House What type of extension do you need? Single storey extension When was the property built? 1980 or later How many stories is the current building? 2 Storeys ...

Post a similar request >

07 May

House Extensions

Silverburn - EH26

Enquiry from: Steven L

Start Date: Immediate

What type of property is this for? House What type of extension do you need? Two storey extension, Would like advice from the pro When was the property built? 1921 to 1979 How many stories is the c...

Post a similar request >

06 May

House Extensions

London - NW6

Enquiry from: Noam G

Start Date: Immediate

hi, i'm in the process of buying a house, which needs a fair bit of work. this would include converting an attached garage into a bedroom, knocking down a couple of walls, doing a small extension int...

Post a similar request >

06 May

House Extensions

Ilford - IG1

Enquiry from: Evangeline S

Start Date: 1 to 3 months

customer made an online enquiry for house extension and confirmed on sms and email they would like a call with a builder to discuss prices.please call to arrange an appointment to quote. are you the p...

Post a similar request >

03 May

House Extensions

Bristol - BS13

Enquiry from: JULIAN P

Start Date: Less than one month

customer in bristol areas is looking to do a couple of projects at the moment, and would like quotes for house extension.confirmed interest via email at 03/05/2025 10:09.please call to arrange appoint...

Post a similar request >

01 May

House Extensions

Leicester - LE7

Enquiry from: Will M

Start Date: Immediate

What type of property is this for? House What type of extension do you need? Property extension When was the property built? 1921 to 1979 How many stories is the current building? 1 Storey (e.g. bu...

Post a similar request >

Local & reliable builders near me

Tell us about your house extensions project

Answer a few quick questions, so we can match you with local builders who can help.

Find up to 4 builders in your area

Get free, no-obligation local house extensions quotes from 4 verified builders working in your area.

Hire with confidence

Compare customer reviews, services and prices, and choose the right tradesperson for you.