Does An Annexe Add Value To A House? | Checkatrade
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Does an annexe add value to a house?

Does an annexe add value to a house? It sure does, and you might be surprised at how much it can add.

Annexes used to be solely known as a solution to deal with an elderly relative moving in and needing a living space – hence the term “granny annexe”. But things have certainly changed and annexes are now a popular way to increase a house’s living space.

In this guide, we explore the question ‘does an annexe add value to a house?’. And equally, how much value a self-contained annexe can add to your property.

How much value does a self-contained annexe add?

The short answer is, yes. It’s estimated that you could add up to 20-30% to the value of your property. That’s some serious value you could add to your home.

That said, the exact value that a self-contained annexe can add to your property will vary considerably, depending on:

  • The size and layout of the annexe
  • Your existing property
  • Where you live
  • The quality of the finish

That figure is often debated because it really does depend on what you started with and the specification of the finished annexe. But it’s very likely that an annexe will almost certainly add value to your home – especially if planned carefully with a well-designed layout.

If you’re ready to start planning your new annexe, speak to an experienced annexe specialist for their professional advice.

Does a granny annexe add value?

In most cases, a granny annexe will add a significant chunk to the value of your property. Especially nowadays when holiday rentals are very common – a granny annexe can become a form of income for a household.

Granny annexes offer multi-functional living spaces that can make a property more appealing to buyers, whether they’re used as extra living space, an office, a home gym or a holiday rental space.

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How much does a granny annexe cost?

The cost of building a granny annexe can vary massively, depending on the size and specification of the annexe. You can expect an average granny annexe to cost somewhere around £90,000 for a new detached building.

Small granny annex in gardenIf you’re planning to convert a garage into an annexe, the average cost is around £14,000.

Often you’ll be quoted costs based on construction per square metre based on the quality of the finish.

Here are some of typical costs for building a granny annexe in the UK:

  • Basic build – £800 – £1500 per m2
  • Standard, high-quality build – £875 – £1650 per m2
  • Premium quality build – £950 – £1800 per m2

To find out more, check out our guide to the cost of building a granny annexe.

You might also be interested in reading our other costs guides to find out prices for loft conversion costs and barn conversion costs.

Benefits of building an annexe

There are a number of great reasons to add an annexe to your home:

  • Add value to your home
  • Expand the living space of your home without moving
  • Create accommodation for relatives to live in
  • Many annexes can be used as holiday rentals to generate income
  • Most councils give a 50% discount on council tax for annexes lived in by relatives

As with all domestic construction projects, you’ll want to enlist the help of experienced tradespeople to carry out the work. You’ll also want to shop around to make sure you’re paying a fair and competitive price for the work. And, thankfully, we’ve got a tool that makes finding multiple quotes super easy.

Our request a quote feature is perfect for getting quotes: you post details about the work you need doing and we’ll send it out to local tradespeople in your area. Try it out – it’s quick and easy!

Selling a house with an annexe

When it comes to selling a house with an annexe, it’s worth noting that they can sometimes cause complications with buyers because some lenders aren’t keen on properties with an annexe. This is because there’s potential for the annexe tenants to obtain rights of occupation – which would make it difficult for the lender to take possession of the property if needed.

It’s certainly possible for buyers to get a mortgage to buy a house with an annexe, they might just not be able to choose any lender – they’ll need to choose based on those that will lend on the property.

As the owner who’s selling a house with an annexe, there’s not much you can do to remedy this – other than ensuring potential buyers are aware of the situation.

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Do you have to pay council tax on an annexe?

Yes, you do. Just like any property in the UK, you’ll have to pay council tax on an annexe. Your local council will determine what tax band your annexe will be, based on the living space – including your main house. The good thing is most councils will offer a 50% discount on the tax bill for your annexe if a relative is living there.

Annexe added to a houseWhen is an annexe a separate dwelling?

Generally speaking, an annexe is not considered a separate dwelling, especially when it’s used in the way that the majority of homeowners use their annexes in the UK – as accommodation for relatives.

It can even be a detached annexe and be classed as part of the same dwelling, such as a garage conversion.

Can you live in an annexe?

Absolutely. An annexe is simply an additional part of an existing dwelling and as such can be lived in – as long as the appropriate planning permission was obtained when the annexe was built (or converted). The vast majority of annexes are built specifically to be used as living space.

Do you need planning permission for an annexe?

Yes, you do need planning permission for an annexe. In the majority of cases where an annexe is being built (or converted) to create new living space, then you’ll need to apply for the appropriate planning permission.

Speak to your local planning office before you begin any work on building an annexe, to ensure that you have the relevant permissions and paperwork in place first.

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