Home renovation costs: what to expect

Work often comes with multiple considerations, and costs can easily rack up, so calculating a realistic home renovation budget is crucial.

Here we look at some of the average costs you might expect to pay if you’re getting your property extended, rendered or rewired.

Disclaimer: Prices change all the time, so the below may no longer be accurate. All prices were accurate as of writing, and should still serve as a general pricing guide. 

How much does a house extension cost?

 

Average rendering cost

Duration of work

Two-bedroom bungalow

£2.5K-3.5K

4-6 days

Three-bedroom semi

£4.2K-5.5K

6-9 days

Four-bedroom detached

£6.7K-8.3K

7-14 days

 

Home extensions are popular, adding 10% – 20% onto your home’s value. However, they aren’t cheap with costs varying depending on the following factors:[1]

  • Your location
  • Material quality
  • Type of extension

It can also cost an average of £750 for an architect or architectural technician to draw up plans[1].

While not a legal requirement, many find it helpful to have a professional involved.

Types of extensions

The three most popular extension types are:

  • Single-storey extension – an extension to one storey of a home
  • Double-storey extension – an extension to two storeys
  • Side extension – adding another room or extra space to the side of an existing building

How much does a single-storey extension cost?

If you’re extending one storey of your home, you could expect to pay the following[2]:

  • Basic quality: £1,350 to £1,650/m²
  • Good quality: £1,700 to £2,000/m²
  • Top quality: £1,800 to £2,500/m² or above

Based on the above, a small extension 20m² in size can cost between £34,000 and £40,000, if you’re using good quality materials.

For a medium-sized extension of 30m², you’d be looking to pay between £51,000 and £60,000.

The work should take about eight to 10 weeks.

How much does a double-storey extension cost?

If you want to extend over two floors, the ballpark figures are as follows:

  • Basic quality: £1,250 to £1,650/m²
  • Good quality: £1,650 to £2,250/m²
  • Top quality: £2,250 to £3,000/m² or above

These figures are similar to a single-storey extension, as you’re only adding walls and floor joists. The roof and foundations will be required either way, but you’re also adding twice the floor space.

If you’re using good materials, a 40m² double-storey extension will cost between £66,000 and £90,000.

A medium-sized two-storey extension of 60m² should cost between £99,000 and £135,000.

Construction should take around 12 to 16 weeks.

How much does a side extension cost?

Another option is a side extension, which usually involves extending the kitchen or living room, and you’d be looking to pay about £1,250 – £2,500 per m².[1]

Prices for side extensions will vary depending on the quality of materials, and how much reconfiguration is required. If you plan to have a kitchen in the extension, for instance, it’ll need plumbing. If you have a gas cooker, you may also need to have the pipes altered.

For a side extension, you should budget upwards of £75,000 – and at the high end, they can cost as much as £300,000.

Building this type of extension should take about 10 to 12 weeks.

What is house rendering?

House rendering is you covering an external wall with cement, lime, acrylic or another mixture.

It’s a relatively cheap way to protect brickwork, gives the building a uniform finish, and can be done in any colour.

How much does rendering a house cost?

There are several types of render, which vary in quality and cost. In addition to materials and labour, there will be additional costs such as skip hire, and scaffolding if you need to render more than one storey.

According to tradesperson-finding website Checkatrade, you should budget £31.50 – £63 per m² for a rendered wall, including painting[3].

But how does this translate to different-sized properties?

These are rough costs using cement render, and assuming that the bungalow won’t require scaffolding. Your tradesman will give you a more accurate quote based on what you need[4].

If you need scaffolding, it should cost between about £400 and £600 a week.

For materials, cement tends to be the cheapest option. Here are the range of options, with costs and considerations[5]:

Types of render

  • Cement (from £10/m²): The most common and industry-standard choice of render.
  • Lime (from £20/m²): Breathable and damp-proof, this also suits older properties.

Types of finish

  • Masonry paint (from £20 to £30/m²): This will help to protect certain types of render. In addition to colour, you should consider the texture and weatherproofing qualities.
  • Pebbledash / roughcast (from £30/m²): A waterproof finish which helps insulate the property. 

Pre-coloured / finished render

  • Acrylic (from £30/m²): A topcoat for new and existing render, which can reduce the amount of cleaning required in future.
  • Polymer (from £30/m²): A type of plastic, which reduces the chance of cracking. This can also be coloured, meaning you won’t need to paint afterwards.
  • Monocouche (from £35/m²): While more expensive, this just requires one coat, meaning reduced labour costs.

How much does it cost to rewire a house?

Old and faulty wiring in a property can be dangerous, so it’s important that your wiring is in good shape. If you move into an older property – especially one aged 25 years and above – getting your wires inspected should be a priority.

The job involves taking out old wires and fittings, putting new ones in, and upgrading the consumer unit. If you’re having new fittings, this may also entail cutting into walls and ceilings.

After installation, the electrician will conduct tests to ensure all the wiring is working properly. This is known as an Electrical Installation Condition Report (EICR), and you’ll receive an EICR certificate once it’s been given the all-clear.

These are the prices you’d expect to pay for rewiring[6]:

 

Average rewiring cost

Duration of cost

Two-bedroom flat

£3K-4K

4-6 days

Two-bedroom house

£1.5K-3K

3-4 days

Three-bedroom house

£3K-5K

5-7 days

Four-bedroom house

£5K-7K

7-10 days

Five-bedroom house

£7K-9K

10-14 days

 

These are average costs. They may vary depending on the location, size and age of your property.

Other factors may also lead to a job taking longer. For example, if the property is occupied, it’ll take longer to complete the job than if the property is empty.

Also, if you have a lot of new fittings to put in, or several bespoke fittings, these will take longer to install than having just a few standard fittings.

If you’re looking to sell your home, here are some home improvement ideas to catch the buyer’s eye.

Home insurance for home improvements

If you’re undertaking large home improvement projects, you need to tell your home insurance provider. If not, you risk invalidating your home insurance policy if anything does go wrong during construction.

You should also check you still have the correct level of home insurance cover when the work’s done. Extensions and other structural changes are likely to increase the value of your property, and you don’t want to be underinsured.

Need some help funding?

In 2021, building an extension was the top reason why people took out an Admiral Money home improvement loan.

You can potentially borrow £1,000 to £30,000* between 12 and 60 months to help get your project started or fund the entire balance.

* The rate you’re offered depends on your individual circumstances and all loans are subject to status. The interest rate offered varies depending on our assessment of your financial circumstances and your chosen loan amount.

https://www.admiral.com/magazine/guides/home/home-renovation-costs-what-to-expect