Planning Permission for a Granny Annexe – Our Service

An integral part of our service is to obtain the necessary permissions from your Local Planning Authority (LPA) to legally build your annexe. This is achieved with a Householder Application and the Caravan Act.

iHUS Planning Permission Granny Annexe Service

The thought of trying to obtain planning permission for a granny annexe might sound complicated but with our planning service, there is little to no work for you to worry about.

When you choose iHUS to build your granny annexe, our planning permission service is automatically included. Our in-house planning specialist will apply for planning permission for your granny annexe and liaise with the relevant authorities on your behalf.

Dual Approach to Granny Annexe Planning Permission

Our unique dual application approach means that you have the best chance of gaining approval, right from the start.

Our preferred method of obtaining planning permission is a Householder Application (1). However, we submit the same plans under the Caravan Act (2), so that should any objections be raised, we have a ‘safety net’. This dual-approach ensures that the planning stage is no longer than necessary, and that building works can start as soon as possible.

1. Householder Application

Most Householder Applications are decided under ‘delegated authority’, where the case officer and the LPA management team will make the decision; it’s quite rare for a full planning committee to be involved in the decision.

Your LPA will have their own adopted planning policies and guidance, meaning that no two applications are the same. And whilst there are national guidelines in place, each LPA has its own specific local adopted policies.

In rare circumstances, one or more specialist surveys may be required to support the application, including: arboricultural (tree), ecological (wildlife), topographical (ground levels), flood risk assessments, archaeological surveys, or a heritage report if you live in a listed building. All of these involve a separate fee payable to the specialist company undertaking the survey.

If your main property is in a conservation area, national park, Green Belt, site of special scientific interest, or area of outstanding natural beauty, the LPA conservation officer will be involved and can influence what can be built and how it looks.

A planning notice is issued when an application is successful; it will always have several conditions attached that must be adhered to. The notice may also be issued with ‘pre-commencement’ conditions, in this instance, these conditions must be officially discharged before works can start, which will incur small fees.

Our planning expert will work closely with your case officer during the planning process to give your application the best chance of being approved. However, if your application is refused, we will review the reasons for refusal and advise on next steps. As a Householder Application is our preferred form of permission to build, we usually recommend that an amended application is submitted or that the decision is appealed.

2. The Caravan Act

Should a Householder Application be unsuccessful, we will fall back to the Caravan Act to obtain permission to build. There are three tests that a mobile home must pass to comply with the Act;

  • Maximum dimensions
  • Method of construction
  • Transportability

All our annexes can be built to achieve these criteria meaning that permission to build your annexe will be achieved one way or another. Your LPA will issue a Certificate of Lawfulness (COL) should there be no objections. For detailed information on the Caravan Act, please refer to our separate document.

Can You Use Permitted Development For a Granny Annexe?

We can’t use permitted development as an option; it doesn’t work for annexes and is intended for outbuildings such as a home office. Normal residential uses, such as separate self-contained accommodation or the use of an outbuilding for primary living accommodation such as a bedroom, bathroom, or kitchen fails the permitted development criteria. Permitted development also has severe restrictions on external eaves heights, making internal ceiling heights very low.

What About Building Regulations for a Granny Annexe?

PWC Ltd, a Government approved Building Control company, inspect all of our work to ensure it meets/exceeds the standards set by Building Regulations.

How Long Does Planning Permission for a Granny Annexe Take?

Initially, we will prepare and submit the application to your LPA. Once validated (which can take up to four weeks), the planning application process takes eight weeks. Here’s how it works…

Weeks 1–3. Public Consultation: your LPA will write to the statutory consultees, this includes; neighbours, Parish Council (if you have one), Ward Councillors, Highways and Water Agency asking for their comments on the application. Any objections will be logged during this period, most LPA’s won’t accept comments after this stage.

Weeks 4–8. An LPA case officer will look after your application up to its decision date (known as the ‘target decision date’) at the end of the 8-week period, within this time the officer we more than likely conduct a site visit.

Throughout the process, our planning expert will engage with your case officer to address any concerns and ensure that the application has the best chances of being successful. Any changes required by your LPA will be fully discussed with you prior to them being agreed with the LPA.

Of course, there are obstacles that can delay this process; usually planning objections or a specialist survey request. This means that the timeline isn’t set in stone, rather an example of the process for most of our customers.

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    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…