How Do You Get Utilities to Your Granny Annexe?

Amongst the many questions you have when building a granny annexe is how you sort out the utilities. Things like water and electricity are essential for comfortable living and no granny annexe would be complete without them. This post explains everything you need to know about getting utilities to a granny annexe.

How Do You Get Utilities to A Granny Annexe?

The short answer here is; you don’t! We do it for you. The first thing you should know about us is that when you decide to choose us to build your granny annexe, we also sort out all the utilities. The work is done after your annexe is lifted into place so that you can move straight into your new home with running water and electricity.

Carry on reading to find out a little bit more about the process of getting the key utilities such as water, electricity and sewerage disposal to your granny annexe.

How Do You Get Water to A Granny Annexe?

Your granny annexe water supply will be connected to the main properties supply. We do this by digging a trench between the house and the annexe and connecting the water. This is usually a straightforward process and is made very easy if your annexe is close to the main property.

Sometimes, if an annexe is situated a little bit farther away from the main property, a water pump may be required to ensure that water pressure is high enough for baths and showers. This will all be established before any work starts so that you don’t encounter any unexpected costs during the build.

image shows a pipe on brickwork

Getting Electricity to a Granny Annexe

Your annexe will be connected to the main property electric supply. However, to ensure that the system isn’t overloaded, the annexe will be on its own circuit. That way there won’t be any blown fuses in the main house and the occupant of the annexe can benefit from their own uninterrupted electricity supply.

All work is carried out by suitably qualified electricians and the cables will be underground rather than above head as these tend to look unsightly and can become damaged more easily.

Connecting a Granny Annexe to Sewerage Mains

The easiest and best option for dealing with wastewater is to connect your granny annexe to the mains sewerage and in most cases, we can do this.

However, if your annexe is too far away from the mains a septic tank might be a better option. A septic tank is a large tank usually constructed of steel or concrete that is buried in your garden so it isn’t visible.

Your annexe should ideally be slightly higher than the mains too to provide a natural flow of wastewater – if your garden is too flat, we can install a pump to improve this process.

Is Connecting Utilities Included in the Cost?

When you receive a quote from iHUS for your granny annexe, the price you see will include a connection to the main utilities.

There are some instances where additional charges will be made, but you will be informed of these beforehand. If your annexe is within ten metres of the mains, then the connection is included. Beyond ten metres, we simply charge per metre.

Additional charges may also be applied where equipment such as pumps or septic tanks must be installed. Most annexes don’t need these, but we will be able to tell you on our initial consultation if it is likely that you will need any of these additions.

image shows a sewer mains

Get in Touch

If you have any questions about utilities and granny annexes, then please contact us. We’re always happy to answer any initial questions you may have about building a granny annexe.

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…