Many homeowners hope to add value to their property at some point.
For those with enough land, annexes are a great way to do this.
This blog explains how much value an annexe adds to a house.
Keep reading for the answers you need.
What is an annexe?
An annexe (sometimes referred to as a granny annexe) is a living space on a larger property’s land.
It usually has facilities that allow someone to live there, including:
- Water supply
- Heating
- Lighting
- Plumbing
- Electricity.
In most cases, an annexe will have a separate entrance to the main house. But the address remains the same.
Some homeowners rent out annexes. Platforms such as AirBnB make this easier to achieve.
Does an annexe add value to a house?
Annexes generally add value to houses – presuming they are done well, i.e., are of a high quality and attractive appearance.
They add value primarily because they increase properties’ living/storage space. Their potential profitability (if rented out) also adds value.
How much value does an annexe add to house value?
Most experts say that an annexe will add between 20% to 30% to the value of a house. On average, this comes to around 25%.
The quality of the work will impact this figure slightly. You may be at the higher end of this range if it’s done to a high standard.
But if it’s done poorly, perhaps only a 10% or 15% increase will be realised.
Of course, this value is only helpful to people selling the property if they get a good return on investment (ROI).
Example scenarios of annexes adding value
On average, if you own a house worth £250,000, adding an annexe will bring the total value up to £312,500.
If you own a house worth £500,000, adding an annexe will push the value up to £625,000.
Are there different types of annexes?
The word ‘annexe’ tends to be all-encompassing. It refers to any type of self-contained living area adjacent to your building.
Each annexe building design can be as unique as the next.
You could vary it based on square footage and number of windows.
Some are built from scratch; others are garage conversions.
You could also introduce entertainment features or an en-suite bathroom.
These varying features will impact the cost and ROI of an annexe. (More about this below.)
How much does an annexe cost?
The cost of an annexe in the UK varies based on:
- The size
- The features
- Your location in the country.
The average price is around £90,000. This can go down as low as £45,000 for the smallest projects.
Meanwhile, the cost can stretch to £150,000 for a larger project or even higher.
Most construction experts charge based on square footage.
This may be around £2,250 per square metre. This gives you guidance on how the price varies based on size.
Make sure to account for water, gas, and electricity installation.
And extra features, such as a television or gym equipment, will push it up further.
Why do people get an annexe installed?
You can unlock several advantages when you install an annexe. The main benefits are listed below.
Increase house value
House values typically increase.
So, many sellers make a return on investment simply stay in a home long enough (without changing it).
Adding an annexe further increases the profit made.
Accommodate more people
An annexe allows you to house more people.
This is useful if you want a family member or friend to live with you. An elderly relative who needs caring for is a typical example.
Independence and privacy
An annexe can also give you more independence and privacy. This allows you to separate yourself from the rest of the house.
For instance, it could be used as a workspace or a gym. This is advantageous for all members of the house that use it.
How long does an annexe take to install?
Constructing an annexe usually takes around 12 weeks. The first step is to lay the correct foundations. The building will then be built on top of this.
More complex jobs may take longer than three months. This often happens when planning permission is needed, for example.
A more straightforward task could be completed within 8 weeks. But it’s possible that the finish won’t be to the highest standard.
You should ask construction experts near you for a personalised quotation about the timeframe.
Ways to keep down costs when installing an annexe
You don’t have to pay full value for an annexe. There are ways to complete the project without spending an arm and a leg.
Don’t go too big
You may need to compromise on the size of the annexe you pay for.
As mentioned above, most construction experts price their services by square footage.
This means that if your add-on annexe is smaller, it tends to cost less.
Research different installers
You should also thoroughly research all the potential installers in your area.
Each one will have different pricing methods, and some will be more expensive than others.
Remember that choosing the cheapest one is rarely in your best interest: balancing quality and price is key.
Negotiate on price
Don’t be afraid to negotiate on price. Some experts will be open to this. And it can save you thousands in a best-case scenario.
Think about materials
Pay attention to the materials that must be involved with construction. If you’re shipping exotic materials from overseas, it’ll certainly cost more.
Especially since it can also require more expertise to install, you may need to set realistic expectations in this area to save money.
Don’t overdo the features
And lastly, think carefully about the features you install in the annexe.
Expensive items such as gym equipment and beds can push up the price.
A surround sound system can also be used for movies. You may need to compromise on this.
Things to keep in mind when paying for an annexe
You shouldn’t jump into getting an annexe without doing research. Here are a few things to think about.
Long-term function
Make sure you think about the long-term function of your annexe.
Even if it could be helpful in the next few months, it may not be worth the investment if it becomes obsolete.
Especially if you don’t plan to sell the house soon. Other, short-term solutions may be preferable.
Look at customer reviews
You should also do in-depth research on the installer you use. Look at customer reviews to see what past clients have said.
Ideally, they may even show you annexes that they’ve installed nearby.
Check on planning permission
Don’t forget that you sometimes will need planning permission for an annexe.
This is common if you live in a listed building. Or if the installation is large and thus blocks light out from a neighbour.
Council tax
Sometimes, it will be considered as a separate building for council tax purposes.
Especially if you’re getting water and electricity implemented, it’s best to research this to find out if it’ll apply to you.
Are there any negatives to a house having an annexe?
Sometimes, an annexe will cause you to be charged extra council tax.
The process of getting planning permission can be time-consuming, too.
You’ll need to tell your home insurance provider. This could result in your premiums becoming more expensive.
Other costs may go up too, such as:
- Cleaning
- Electricity
- Water
- Gas.
