What is an Annexe?

In simple terms, an annexe is a self-contained living space that is either attached to, or located within the grounds of, a main property.

Think of it as an addition to your home: positioned within your boundary and designed to provide extra living space for a range of uses. If you’re weighing up your options, you can also compare garden rooms, garden homes and annexes in our guide.

A granny annexe is very similar, but with a more defined purpose. It’s typically used as independent accommodation for a family member, often an elderly parent, allowing them to live close by while keeping their privacy. Many iHus builds are used in exactly this way, helping families support loved ones while creating comfortable, flexible living. These spaces can serve plenty of other purposes too, depending on what you need.

What is the difference between a garden room and an annexe?

You’ll find many companies offering garden rooms online, but these shouldn’t be confused with a fully self-contained living space.

A garden room is typically an additional space within a property, ideal for a home office, entertaining or relaxing. It’s generally used during the day or evening, not designed for full-time living. An annexe, by contrast, provides a complete living environment: a kitchen, bathroom, bedroom and living space, everything needed for day-to-day life.

In short, a garden room adds space to your home, while an annexe creates a home within your property. For a full comparison, see our detailed guide.

 

What’s involved in building an annexe?

Building a self-contained living space is a detailed process that takes careful planning and coordination. An overview of the iHus process:

  • Initial contact — enquire about your project and receive a brochure to get started.
  • Onsite consultation — a member of our team visits your home to assess feasibility and discuss options.
  • Follow up — we create a detailed plan covering design, timelines and specifications.
  • Confirmation — planning permission is submitted, backed by our money-back planning guarantee.
  • Project communication — a dedicated contact keeps you informed throughout.
  • The build — constructed to high standards in our Doncaster facility.
  • Installation — delivered and assembled on-site once the groundwork is complete.
  • Completion — the final touches, including our signature move-in.

This is a summary; find out more about our process.

 

Can an annexe be built as an extension to your home?

While many annexes are standalone buildings, they can also be designed as an extension to your existing home.

With a custom build, it’s possible to create a connected living space that blends seamlessly with your property while still offering independence. Whatever the size or shape of your garden, a bespoke approach lets you design a solution that works for your home and lifestyle.

 

Choosing from the iHus annexe range

If you’d prefer a more traditional option, there are plenty of pre-designed layouts to choose from.

These vary in size, number of bedrooms, roof type and internal finish, giving you the flexibility to create a space that suits your needs. From a cosy one-bedroom Cantley to a larger design like the Wheatley, explore the iHus granny annexe range. You can also visit the iHus community to see real examples and guided tours of completed homes.

 

Common annexe myths, cleared up

As these builds have become more popular, a few misconceptions have stuck around. Here’s the reality behind the most common ones.

Myth: an annexe doesn’t need planning permission

Reality: planning permission is usually required, and the rules vary depending on your local authority. Working with an experienced team improves your chances of approval. Learn more about planning.

Myth: an annexe goes up almost overnight

Reality: quality construction takes time. The build itself is typically 8–12 weeks, with the full process including planning taking around 5–6 months. Find out more.

Myth: an annexe can have its own separate address

Reality: no. An annexe must remain within the same property boundary as the main home.

Myth: annexes don’t last

Reality: built with high-quality materials and expert construction, an annexe can last for decades. Every iHus build is backed by a 10-year guarantee for added peace of mind.

Myth: annexes are only for older people

Reality: although they’re often used for elderly relatives, annexes are increasingly chosen by younger generations looking for independence.

 

How can an annexe help your family?

We look at the financial side in our guide to whether an annexe is worth it, but the advantages go beyond money.

Having a self-contained living space nearby lets families support one another while keeping their independence. It can help reduce care costs, provide a hand with childcare, and create a more flexible living arrangement for everyone. Ultimately, it lets families stay close while still enjoying their own space.

 

Frequently asked questions

What is an annexe in simple terms?

An annexe is a self-contained living space built within the grounds of a main home.

Do you need planning permission for an annexe?

In most cases, yes. It depends on your local authority and the details of your project.

Can an annexe be lived in full-time?

Yes. Annexes are designed to provide full residential living.

What is the difference between a garden room and an annexe?

A garden room is for leisure or work, while an annexe is designed for full-time living.

 

Find out more

Every annexe is unique. Speak to a member of the iHus team to explore your options and create a space that works for your family.

Explore the rest of our annexe definitions:

Get started by downloading a brochure today.