Planning a granny annexe is a big project and beforehand you will have plenty of questions. Here on the iHUS blog, we try to answer as many of those as possible. Granny annexe legal requirements will likely be one of your first thoughts; particularly planning permission.

Below we answer some of the most common questions including what to do about planning permission.

Granny Annexe Legal Requirements

In this post, we will cover the most common questions relating to granny annexes and the law.

  • Planning permission
  • Ownership
  • Council tax

image shows a smiling older lady

Granny Annexe Planning Permission

Granny annexe planning permission is usually one of the first legal requirements that our customers ask us about.

You may have already discovered by now that you will need planning permission for your annexe. if a structure in addition to your house is going to be a dwelling, then you will always need either planning permission or a Certificate of Lawfulness from your local authority.

Planning permission for your granny annexe can be one of the most complex aspects of the project but there is no need to worry about this when you build your annexe with iHUS as we take care of planning as part of our service.

Even on our first consultation, we will be able to advise you on the likelihood that your plans will gain approval. For example, if you really want a pitched roof on your annexe, with a quick survey of your garden and surroundings, our expert consultant will be able to tell you if you are likely to gain permission.

Granny Annexe Ownership

Something that crops up before you start your granny annexe project is the legal issue of ownership. This is something that your family must discuss before you make any plans to build an annexe.

If you have a family member who is looking to release equity and downsize there are some beneficial reasons to do that in relation to Inheritance Tax and for the property owner, the value of the main house will usually increase and become more desirable when it comes to selling.

Whilst there are no rules on who should own a granny annexe when it comes to selling a property, an annexe must always be sold alongside the main residence. It will not be classed as a separate property when it comes to selling.

It is best to discuss who ‘owns’ the annexe beforehand and make sure that all parties are in agreement.

image shows a family thinking about granny annexe legal requirements

Granny Annexe Council Tax

Granny annexes used to be considered a separate dwelling and therefore was not exempt from council tax. However, in 2014, the government revised this as many people saw it as unfair. As many people use annexes to house elderly relatives, they are saving the government money by reducing the strain on elderly housing and care services.

So long as the person living in your granny annexe is a relative, or you only have it for your own use, then you should be entitled to a 50% discount on council tax. This is good news for anybody who is planning a granny annexe that isn’t for a granny – some young families choose to live in an annexe, for example.

If the family member living in the annexe is a dependent family member then you will be exempt from paying council tax altogether. Anybody over the age of 65 is classed as a dependent relative, as are severely disabled people.

The process to apply for a discount or exemption is easy and should be done with your local authority the same way you would apply for other council tax discounts, single person discount, for example.

Want to Discuss Granny Annexe Legal Requirements?

If you still have a question about any of the legal aspects of building a granny annexe, then please contact us.

With many years’ experience in the field, we are able to answer any questions or concerns that you or other family members may have.

View Our Annexes

The Cantley is the smallest annexe in our Core range and is one of our most popular models for independent living. The floorplan is designed to maximise space and fits comfortably into most back gardens.
As one of our most popular one-bedroom annexes, the Bawtry is the perfect choice for elderly care or an independent young adult looking for their first home.
The Ravenscroft is a spacious one-bedroom annexe, designed for those with a larger garden plot. All three footprints utilise a central shower room to separate the bedroom and the open-plan kitchen/living area to maximise living space.

Recent Projects

Speedwell Annexe


Our customer moved into her Annexe in January and is thoroughly enjoying her lovely new home. She describes her Annexe as ‘Warm Sunny Cosy & Comfortable’. Click below to watch an exclusive interview with the owner and watch their Annexe walk through!
Williamson bespoke granny annexe

Jenny Williamson

The Williamsons family moved into their Annexe over 3 years ago. When visiting the family they told us life in their new home exceeded their expectations for many reasons. So much so, they wanted another iHus building! Click view to find out more about their story and take a look around their Annexe.

Wendy Hamm

In Autumn 2020 Wendy Hamm and her family approached iHus as they were contemplating an annexe build in their back garden to house Wendy’s mother. Wendy’s mother Jane, 82, was living over an hours drive away from the family. Wendy’s day to day responsibilities meant that visits to Jane were a lot less frequent then they would have wished. Read their story here.

Shelagh Booker

All of our iHus annexe are customised to meet the want’s and needs of their owners. Take a look around Mrs Bookers annexe and listen to what her and her daughter have to say about their iHus annexe journey below.

Download Your Free Annexe Brochure

Simply fill in the form and you will be emailed a link to download our 32 page annexe brochure.

    Simply fill in the form and you will be emailed a link to download our 32 page annexe brochure. Please check your Junk mail if your brochure doesn’t appear in your inbox

    Request A Hard Copy?:

    Download Your Free Annexe Brochure

      Simply fill in the form and you will be emailed a link to download our 32 page annexe brochure. Please check your Junk mail if your brochure doesn’t appear in your inbox

      Request A Hard Copy?:

      Talk to a Consultant

      We know that building an annexe can seem daunting which is why we created our Signature Move process.

      It all starts with a conversation where we want to get to know you better, understand what you need and give you an opportunity to ask any questions you might have.

      To get started complete the form and a member of our team will get in touch to book you an appointment with a consultant…