Is Your Garden Suitable for a Granny Annexe & How To Find Out

There is a misconception that in order to install a garden granny annexe on your property you need lots of spare land or that you won’t be able to obtain planning permission. This isn’t the case though – the majority of iHUS customers have an average suburban back garden and find the planning process very easy.

Read on for some simple checks you can perform at home to assess how suitable your garden is and how likely you are to gain permission to build a granny annexe.

Is My Property Suitable for A Garden Granny Annexe?

The major consideration is the size of your garden. Some gardens it will be obvious that you won’t be able to fit a decent sized annexe on (think courtyard gardens on terraced houses) but the average British back garden that most of us have will usually accommodate a granny annexe.

Houses built from the 1920s onwards tend to have bigger gardens as the importance of having outdoor space was becoming more widely recognised. According to estate agent, Foxtons, the average back garden is 15-metres long – around 50-foot. The width is normally a lot smaller, giving most gardens a long thin appearance. This does limit what structures you can fit in the average sized garden, but it is entirely possible to fit a granny annexe on a typical back garden.

garden granny annexe measurements

Another issue you may want to consider is how the ground is laid. Luckily most gardens tend to be level and flat. But some gardens can be sloping. This can be an issue when it comes to installing a structure of any kind, such as a shed or conservatory.

The good news is that this doesn’t automatically mean you can’t have a granny annexe. providing there is enough space, groundwork can be done to level out an area of your garden, creating a nice flat area for your annexe to stand on. This will be an added expense to the overall cost of your project though, so keep that in mind.

When considering potential positions to situate your granny annexe, you must also consider getting utilities to the annexe. The further away from the mains and the house, the more expensive it will be to get you connected to essential utilities.

How Do I Check That My Garden is Big Enough for a Granny Annexe?

Granny annexes can vary in size, our core annexe range is available in one- and two-bedroom models and there are some considerable differences between them. So, before you get out the tape measure, make some important decisions such as how many bedrooms your annexe will need. Build a short list of the models that suit your needs and you think could potentially fit in your garden.

Planning permission

It is important to note that you consider Local Planning Authority when choosing an annexe. You can’t have a granny annexe that is larger than the footprint of the main house.

The garden granny annexe is considered ancillary and subordinate to the main house and must, therefore, be smaller.

Measure your space

Time to get out the tape measure! Using graph paper, plot out the overall size of your house and garden. You can usually find out the measurements of the overall footprint from site location plans or your title deeds. If not, you can measure the footprint yourself. Add onto that the overall footprint of the iHUS annexe you are interested in. If less than 50% of the garden area remains, then it is likely that the annexe will be too big, and you may struggle to gain permission from the Local Planning Authority.

image shows a tape measure which is an essential tool when choosing a granny annexe

Get in Touch

If you still aren’t sure how to measure your garden or if you could fit an annexe on your plot, then please get in touch. Our team will be happy to advise you and we offer free consultations where we can measure your garden and advise you on the most suitable models for your plot.

Give us a call on 0808 164 1111 or use our contact form to send us a message.

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Recent Projects

granny annexe projects

Jenny Haughton

We recently visited the Haughton Family to see how garden annexe living was working out for them. It's safe to say they feel like it was the perfect choice. Watch the video below to hear their expe...
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 a...

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 d...


This idyllic annexe is home to Theresa and Austin situated at the bottom of their daughter and son in law’s garden. Having always lived very closely to one another, the family were convinced this w...

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Download our iHus annexe brochure

If you would like to download our annexe brochure please complete the form below. You call also request for a copy to be posted to your home address. Have any further questions, why not request one of our team get in touch?