What is the cost of a granny annexe? It’s a question we get asked a lot at iHUS with enquiries coming in each day – a simple question, you might think. In fact, it’s not quite so simple to answer, as each iHUS build has its own intricacies and features that make it a home for each of the families it benefits.

While answering this question to a number of customers we decided to create an overview that highlights a number of considerations and influences that should be at the front of your mind as you start to plan your new investment.

Consider The Benefits

Before we look at the costs of building a granny annexe, let’s indulge ourselves and look at why we’re building a new home in the first place – this should always be at the heart of any project. Understanding the values and benefits it brings to your family is key to getting the building right. You want your new build to be a home that you love and you’re proud of above anything else.

First of all, there are the financial benefits – with the cost of care increasing so much, having dependent family nearby can save a lot of money, whether this is later in life with parents or with younger family who may have a disability or need additional support.

Care is not the only financial benefit. The housing market has become unaffordable for so many young people. Often they cannot afford to leave home. The luxury of an annexe your garden gives them independence as well as giving you space and peace back.

Family first – having your family nearby is worth more than anything at all. Knowing that your loved ones are nearby gives you peace of mind that they are happy and comfortable.

Family at table

Finally, your new annexe gives you a chance to get creative. Often within our homes, we have an existing theme or a style to keep to. Your annexe is a blank canvas and no matter what purpose it will serve you and your family for years to come, you can make it your own from day one.

What can influence the cost of a granny annexe?

While every granny annex should be unique in its finish – there are a number of factors that will play a major part in the final cost of your build. These can include:

  • Size matters: As a rule of thumb, the larger the build, the more it will cost. It’s obvious really that the more materials and labour needed in constructing your build, the more financial resource is needed.
  • The number of bedrooms: This usually goes hand in hand with the size. The more bedrooms, the bigger your annexe will likely be.
  • Shape: Layout could be a large contributing factor to the final bill. The more complex a design, the likelier it is to bring a larger price tag.
  • Roof: Flat roof or pitched? There are different styles and finishes too but typically a pitched roof will cost more than a flat roof.
  • Kitchens and bathrooms: How luxurious do you want these important features to be? The finishes are limitless. Keeping it plain and simple may save you some money – but it’s always worth a treat as far as we’re concerned.
  • Utilities: Are the existing connections for gas, electric and water simple enough to hook up? Or does the base work need completely relaying? We’ve seen many different scenarios, the details here will certainly be a factor in cost.

As you choose your specification, bear these in mind.

Annexe Upkeep

Once you’re the proud owner of a granny annexe on your property, there are the regular bills you will need to pay. These include your utilities, potential council tax (though this is often at a reduced rate or free), and the general maintenance costs that you would associate with a home.

man reading

However, it is certainly worth remembering that as a new build, and as your annexe is smaller than your home dwelling, these will be considerably less than that of the main property.

Add value to your home

We recently wrote about the value of an annexe to your home and to your family. This includes the rarity and desire for these spaces and the longevity of keeping them in your family. When you are considering the cost of a granny annexe it is important to remember this.

While on paper the initial outlay may be a substantial figure. The true value of your build significantly outweighs this over and over.

A turnkey solution

At iHus we have a core range of annexes to suit all budgets. From a cosy one-bedroom Bawtry to a spacious two-bedroom deluxe Hatfield. You can even extend this further and choose a completely custom build.

Once you have settled on your model, the finishing touches and details are down to you – you can be as lavish as you wish, or if you are looking to save, our standard features will continue to wow you, your friends and your family.

We offer a complete turnkey solution from discovery and design to you moving in and putting your feet up with a cup of tea.

Contact Our Team

Get in touch with the iHUS team, download our brochure to see the full range, book a virtual consultation and be prepared to be amazed at our solutions.

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    Recent Projects



    This 1 bedroom bespoke Annexe is home to a family from South Africa, their Annexe has enabled them to live in an area that they love close to their beloved family and grandchildren. Find out how the family are getting on, by watching their interview and Annexe walk through video…


    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.

    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…