House Extensions Cost

conservatory costs

conservatory costs


How much does a home extension cost? As with any build, it comes down to a number of factors. However, the size and quality of the extension are going to be the deciding cost factors.

But, with Conservatory Prices UK, you can cut the cost of a house extension. Our house extension cost calculator makes it easy to compare quotes for house extensions. It’ll take minutes for you to find the best quote for your needs.

Additionally, many of the companies we work with are fully accredited by bodies like FENSA and CERTASS. Not only that, you’ll get accurate prices for the time you’re looking through our house extension cost calculator, reflecting changes caused by Brexit and COVID-19 and ensuring you get a comprehensive quote.

How Much Does a House Extension Cost?

Typically, house extension prices will start from £1,000 per m2 to £1,500 per square metre.

For example, a 20m squared extension that is 4m x 5m can cost anything from £22,000 to £28,000.

A basic single-storey extension might start at around £1,200 per square metre.

Of course, prices will reflect the type of materials used, the complexity of design and where you live in the UK.

However, with our house extension cost calculator, you’ll always find the best house extension cost estimates in your area.

Small Extension Prices

Size Cost

Standard Extension Prices


Large Extension Prices


Other Extension Cost Factors

Prices will cover the essential elements of the build. This includes constructing the foundations, building the walls, insulating and plumbing and electrics.

  • Labour
  • Foundations and footings
  • Plastering
  • Structural Openings
  • Brickwork
  • Electrics and plumbing
  • Internal Decoration

Expect to add on 10 -15% for professional fees:

  • Architects
  • Planning Permission
  • Building Regulation
  • Structural Engineer

You will also have to consider VAT. Your home extension cost could go from £40,000 to £60,000, although you could reduce this by using our house extension cost calculator by up to 40%!

Most builders will be able to give you an idea of how much your house extension will cost per square foot or metre. The average cost should cover design through to decorating but it’s worth having a back-up just in case. Think about having a 10-15% contingency in case of unexpected costs.

Building Site Constraints

You will have to factor in additional costs about your site. If you have a complex site, you’ll need to ask your builder to factor in extra costs such as:

Soil type – do you have a specific type that demands a certain technique or material?

Changes to the existing structure – any changes to steel work or walls?

Ease of access – will any drainage, pipework or gas meters need to be moved?

With our house extension cost calculator, you can get in touch with companies to discuss these issues. From there, you can get a more accurate house extension cost estimate.

House Extension Quotation Breakdown

extension prices

House Extension Cost Calculator

Use our free house extension cost calculator for instant, online guide prices. Our house extension cost calculator is free, easy to use and gives you an extension cost within minutes.

How Can I Extend My House Cheaply?

Home extensions can vary greatly. In shape, size and therefore budget – this is why the answer is never a straightforward one.

You will have to first decide how much you are willing to spend. This may come down to a matter of resources, aspirations and reality checks.

However, there are many ways you can cut extension costs and extend your home cheaply. Taking the time planning the smallest of details can help you save money down the line.

Everything from light fittings to socket locations and flooring need to be considered. Plan these well from the outset and you’ll save on alterations at a later stage.

There are many ways you can fund our extension project. Ideally, you would use any savings you have but in reality, this isn’t always viable.

Fortunately, our house extension cost calculator can help you find out what you should be paying, meaning you can plan your budget more effectively.

Re-Think The Design

It’s good to know exactly what you want from your extension at an early stage. Is your design the best use of space?

Rather than re-thinking your budget, you will want to take another look at your plans and extension design. Simplifying the design can help shave a bit of money off your project.

You might want to hire a professional to help you with this. Cutting certain elements of the design could ruin the look or function of your space. You don’t want to have budget versus profit.

Curves and corners can be costly to build. A rectangular or square footprint with a simple pitched roof will be much more affordable. It won’t compromise the builds quality either.

Stick To It

Once you have the design carefully planned out, it’s important that you do your best to stick to it. Any changes will cost money. Ensure you have a building contract with an itemised budget and an order of works in place.

Any project has the potential to yield a nasty surprise, as well as temptation to upscale. This is why you must draw up a robust budget and stick to it as best you can.

With our house extension cost calculator, you’ll get comprehensive quotes for your whole build. That way, there won’t be any nasty surprises when you pay the final bill.

Get The Timing Right

Time your extension carefully. Bad weather can cause delays, and this means increased labour costs and rejigged schedules. This something that will need to be thought about, especially if you plan on renting while you extend.

Damage from wind and rain can up your costs too. A simple extension can become a complete redecoration job if rain penetrates tarpaulins.

Spring or the Summer period is usually the best time to extend, or when prolonged periods of dry weather is expected.

For example, Summer is the ideal time to plan an extension. This allows you to get quotes in the Autumn, ready to go for Spring.

Avoid Complicated Groundworks

You will want to try and avoid complicated groundworks where possible. Avoid building too close to trees, drains and sewers as this will increase groundwork costs.

House Extension Cost Calculator Prices

To get a house extension for less, use our online house extension cost calculator today. At Conservatory Prices UK, we put you in touch with local installers near you who are accredited, trusted and affordable. You’ll get multiple quotes for your house extension, meaning you can compare prices to get the best deal. These quotes will be comprehensive, and there’ll be no hidden surprises.

If you’d like to find out more, contact Conservatory Prices UK today by using our online form or calling 0800 124 4307 today.

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