The Granny Annexe Building Process

Building a granny annexe is an exciting project for both the homeowner and the person who will move into the annexe. But in addition to excitement, there is bound to be a little bit of stress or worry, especially if you are managing the project yourself or using different contractors for each part of the project.

That isn’t the case when you choose iHUS as your supplier, as we carry out each part of the project for you, meaning you have little to no work and can just wait for the keys to be handed over. Read on for more information on the annexe building process.

Getting Started Building a Granny Annexe

The first steps are often the scariest, but it couldn’t be easier when you use iHUS to build your dream annexe.

Once you have got in touch with us, our tried and tested process is put into motion. One of our consultants will visit you at home to discuss the many options that are available to you.

Our process includes a site survey, design and advice. We review the suitability of your site, listen to your ideas and show you what options are going to be the best options for your family.

Once you have chosen a model from our core annexe range, or even a customised option, the real work can begin.

older couple talking


Annexe Building and Planning Permission

Annexe planning permission is usually considered one of the trickiest aspects of building an annexe but there is no need to worry as we also take care of that for you.

iHUS offer a planning permission service, which is inclusive of the total cost of your project.

Once designs have been finalised and you accept our quote, we start the ball rolling with your Local Planning Authority (LPA), submitting plans and liaising with them on your behalf.

You can read more about our planning service here.

Annexe Building Begins

Once the planning has been submitted, we start work preparing the ground at your property, ready for your brand-new granny annexe. The foundations will be laid and service connections set up for water, gas and electricity.

Meanwhile, your annexe will be constructed in a cassette format, unless we tell you otherwise, in our 2,000 Sq Ft factory in South Yorkshire.

Once the site is ready, your granny annexe will be delivered as a “flat pack” on a Hi-Ab wagon and erected on site. We then fit out your new home both internally and externally to the specification we agreed at the consultation stage.

How Long Does It Take to Build a Granny Annexe?

The process of building a granny annexe, from breaking ground to handing over your keys, will normally take around 6 or 7 weeks.

For small annexes, it may be 5 weeks and for the larger builds, we may need 8 or 9 weeks. As every granny annexe we build is bespoke, the actual timeline will be determined during the first stages.


Contact iHUS

As you can see, the annexe building process is actually quite straight forward – especially when you use a full turnkey service like ours. We take care of each and every part of the project for you, meaning that you can relax and just wait for the keys to your brand-new home.

Feel ready to start your own project?

If you have any questions about our annexe building service or want to book a free consultation, simply get in touch. A member of our team will be happy to answer any questions you 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



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 way of life wasn’t going to end anytime soon, & their wonderful annexe has made this a reality!
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.

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…