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 exploring different options, you may also want to compare garden rooms, garden homes and annexes here.

A granny annexe is very similar, but with a more defined purpose. It is typically used as independent accommodation for a family member — often an elderly parent — allowing them to live close by while maintaining privacy.

At iHus, many of our builds are used in this way, helping families support loved ones while creating comfortable, flexible living arrangements. However, these spaces can serve a wide range of purposes depending on your needs.

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What is the difference between a Garden Room and an Annexe?

You will find many companies offering garden rooms online, but these should not be confused with a fully self-contained living space.

A garden room is typically used as an additional space within a property — ideal for a home office, entertaining, or relaxing. These spaces are generally used during the day or evening but are not designed for full-time living.

An annexe, on the other hand, provides a complete living environment. It includes essential features such as a kitchen, bathroom, bedroom, and living space — everything required for day-to-day living.

In simple terms, a garden room adds space to your home, while an annexe creates a home within your property.

For a full comparison, visit our detailed guide.

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What is involved in Building an Annexe?

Building a self-contained living space is a detailed process that involves careful planning and coordination.

An overview of the iHus process includes:

  • 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, supported by our money-back guarantee
  • Project Communication – A dedicated contact keeps you informed throughout
  • The Build – Constructed in our Doncaster facility to high standards
  • Installation – Delivered and assembled on-site once groundwork is complete
  • Completion – Final touches including our signature move

This is a summary of the process. Find out more about our process.

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A Granny Annexe Extension

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

With a custom build, it is possible to create a connected living space that blends seamlessly with your property while still offering independence.

No matter the size or shape of your garden, a bespoke approach allows you to design a solution that works for your home and lifestyle.

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Annexe Properties

If you are looking for a more traditional option, there are many pre-designed layouts available to choose from.

These can vary in size, number of bedrooms, roof type, and internal finishes — giving you 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 core range.

You can also visit the iHus community to see real examples and guided tours of completed homes.

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Annexe Myths

As these types of builds become more popular, there are still several common misconceptions.

You don’t need planning permission

This is not the case. Planning permission is often required and varies depending on your local authority. Working with an experienced team can help improve your chances of approval. Learn more about planning.

Installing a Granny Annexe is quick

Quality construction takes time. Typically, builds take 7–11 weeks, with the full process including planning taking around 5–6 months. Find out more.

Can my Annexe have a separate address?

No — it must remain within the same property boundary as the main home.

Annexes can’t stand the test of time

With high-quality materials and expert construction, these buildings can last for decades. iHus offers a 10-year guarantee for added peace of mind.

An annexe is only for older people

While often used for elderly relatives, these spaces are increasingly used by younger generations seeking independence.

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How Can an Annexe Help My Family?

We recently explored the financial benefits in our cost guide, but the advantages go beyond money.

Having a self-contained living space nearby allows families to support each other while maintaining independence.

It can help reduce care costs, provide support with childcare, and create a more flexible living arrangement for everyone involved.

Ultimately, it allows families to stay close while still enjoying their own space.

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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 — this depends on your local authority and project details.

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.

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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.

Get started by downloading a brochure today.