A granny annexe with a store room

What Is a Granny Annexe?

In the UK, granny annexes are becoming increasingly popular for those looking to ensure their family members are cared for in their old age.

We’ve put together an easy-to-follow guide where we answer the most frequently asked questions regarding granny annexes. We’ve also provided details on what benefits you can expect with a granny annexe and what you’ll need to consider before committing to a purchase.

Read on to find out more about granny annexes…

What is a granny annexe?

A granny annexe can be defined as a secondary building constructed within the property lines of a home that is separate from the main house. A common purpose of a granny annexe is to house an elderly relative who would like to preserve their independence but requires additional care in their old age.

A high-quality granny annexe is essentially a self-contained building in its own right, equipped with everything you would expect to find within the average home. This usually includes a bedroom, living quarters, a kitchenette, and a bathroom. However, to qualify as an annexe, it does need to be reliant on dedicated external services from the main house, such as power supply and drainage.

Are granny annexes becoming increasingly popular?

Yes, opting for granny annexes is becoming increasingly popular here in the UK for those looking for a future-proof investment.

The Valuation Office Agency has released figures revealing thousands of granny annexes have been built across the UK in recent years, with an increase in demand of at least 16% across Wales and England alone.

Can I design the layout of a granny

3D floor plan of a modern one-bedroom Bespoke Granny Annexe with an open living area, kitchen, and bathroom designed for independent living by Rubicon Garden Rooms.

Yes, within certain parameters, you’ll be able to customise a granny annexe to suit the needs of your relatives, depending on the provider you choose.

For example, here at Rubicon Garden Rooms, we offer bespoke annexe garden rooms that can be tailored to suit the preferences and requirements of your loved one. However, to minimise costs, it is often best to work within our defined design parameters as something that's too bespoke can end up costing much more.

Depending on your requirements, our annexe-style garden rooms can also be built without Planning Permission. Click here to contact us for more information on what we can do for you.

How much value does a granny annexe add to my property?

According to many property experts, a granny annexe project will add substantial value to your property. However, the amount of increased value will depend on several factors. For example, factors that influence added value can include (but are not limited to) the size of the outbuilding, how functional the space is, the quality of the craftsmanship and so on.

As a general guide, Checkatrade, one of the UK’s leading directories for sourcing vetted trade professionals, suggest that a granny annexe can add 20% to 30% to the value of a property.

Do I need planning permission for a granny annexe?

Sometimes, but not always. We’ll explain below.

Depending on the type of construction and the approach taken, a granny annexe will often need planning permission and full building regulations approval. The trouble with this is not only the costs of the application paperwork and detailed architects drawings and structural calculations, all of which can add about £5,000 to costs, but also the fact that planning will impose limits on the design, and building regs will add costly elements such as radon barriers, sprinkler systems etc, adding substantially to costs.

This is a very costly approach, and not only adds considerably to the initial application timescales and complexity but also adds to the length of time it takes to build on-site, with the amount of disruption to your garden and the inconvenience and disruption to home life not being minor factors.

Thankfully, there is a way around all of these issues, saving time, cost and inconvenience, whilst adding all of the benefits offered by a stand-alone granny annexe. Our approach is to use The Caravan Act as a means to achieve these goals.

Again, this is not without complexity as it does need the input of our specialist planning team to ensure everything complies with the rules for transportability and pre-fabricated construction methods etc. Please note, however, that in this instance you are not buying something sub-standard, it is built to the same high standards as you would expect from a traditionally constructed building, including substantial insulation, triple-glazed doors/windows, and plastered interiors. It's just a way around the complexity of the rules.

At Rubicon Garden Rooms, our granny annexe garden rooms offer all of the benefits of a traditionally built granny annexe - but without the need for Planning Permission*. However, to ensure that all the boxes are ticked, we apply for a Certificate of Lawful Development on your behalf as part of our package.

This ensures that your Local Authority acknowledges our proposals are within the rules and legislation and nullifies any complaints from your neighbours - not carrying out this step can lead to all sorts of queries post build and so, whilst not essential, is highly recommended.

If you’d like to chat about a granny annexe project or simply find out more about what we can offer, click here to contact us.

How much does a granny annexe cost?

Granny annexe with two bedrooms
The overall cost of a granny annexe project will depend on several factors. This can include location, the provider, the size, or whether you require bespoke customisation.

As a general guide, according to HomeHow, the average price of building and furnishing a granny annexe can range from £80,000 up to £200,000 and beyond.

If the estimates shown above seem somewhat unattainable, don’t worry, there is another option. Here at Rubicon Garden Rooms, our granny annexe garden rooms are built to an exacting standard, and our prices start from just £49,995 for an 8m x 4m one double bedroom annexe complete with shower/toilet and kitchenette.

What’s more, we understand the importance of ensuring that your investment matches the needs and preferences of your loved ones. That’s why we offer bespoke creations and the option to customise existing garden room models here at Rubicon Garden Rooms.

To talk to us about our pricing and what we can do for you, click here.

Click here for more information on our Annexe Style Garden Rooms

View a one bedroom granny annexe in our Deeside showroom:

A one bedroom granny annexe in the Rubicon showroom

Factors to consider

Similar to any big project, investment or long-term commitment, there are several factors to consider before purchasing a granny annexe.

The needs and preferences of your loved one

As the granny annexe will be where your elderly relative resides, it’s essential to consider their wants and preferences, along with their needs and requirements.

See below for several questions to ask yourself before deciding on a granny annexe:

  • What care requirements does my loved one have? (this will help you to identify whether you’ll require a custom build).
  • Does my loved one require a live-in carer now or in the future? (if so, a contingency plan, such as additional bedrooms, will be required).
  • Is a granny annexe the best option for my elderly relative?
  • What size is big enough for my elderly relative to be comfortable? And can I accommodate this in my existing outdoor space?
  • How can I customise a granny annexe to make my loved one more comfortable?
  • Will my loved one be content with living this close, or are there alternative options that they may prefer, such as a retirement village?
  • Is my loved one mobile, or will they require additional features for comfort and support (e.g. ceiling hoists or ramps for wheelchair access)?

Remember, as your loved ones get older, their needs can change, so it's always best to think ahead giving particular attention to accessibility and mobility around the living spaces.

The needs of you and your family

You’ll need to discuss your plans with your household, as having an elderly loved one move to your property is a long-term commitment that may alter your day-to-day lives as you know them now.

Installing a granny annexe for an elderly relative is one of the most caring and practical solutions for those who need to care for their family as they grow older. However, a simple discussion regarding the logistics of how this will work and what life may look like can resolve any potential feelings of confusion or worry.

Shared responsibility

Adding a granny annexe to your property to provide care and support to a relative is a big responsibility. And, if you have siblings, you may need to initiate discussions with them surrounding expectations you may have before carrying out your plans.

Ensuring your elderly relatives are cared for will be in the best interests of everyone involved. However, as an example, you may need to discuss the shared financial responsibility of care or costs associated with having the granny annexe installed, and what this may look like for your family.

We advise reaching an understanding before any plans are put into action, as your family unit must understand and accept the terms of the shared responsibility, whether that be financial or helping to care for your relative, to avoid any potential conflict in the future.

Your future plans

Whether they are in the near or distant future, you’ll need to consider any life-altering plans you may have before having a granny annexe installed.

For example, you may consider asking yourself:

  • Does my current property support the needs of my family now and in the future? (If not, you may want to consider selling your home and moving to a more permanent residence before having a granny annexe installed).
  • Will I need to move for work?
  • What can I expect the return on investment to be on the granny annexe I’ve chosen? Does it support my future plans? (Depending on whether your loved one has specific care needs that require customisation, you may want to consider an option that can be converted to cater to the average prospective buyer).

The benefits of a granny annexe

There are many social, practical, and financial benefits to opting for a granny annexe to care for an elderly loved one. See below for the main reasons why people decide to go forward with having a relative move into a granny annexe on their property.

A granny annexe will increase the value of your property

As we mentioned earlier, a granny annexe is essentially added living space. This, of course, can have a positive impact on the overall value of your property, making this solution a long-term investment.

Opting for a granny annexe is a budget-conscious alternative

If you’re faced with a situation where you’re required to weigh up the options available for your elderly relative, a granny annexe may very well be the most viable option from a financial perspective.

Lottie, a leading service provider that helps people compare care homes and retirement communities across the UK, reported that the average monthly cost of a care home is approximately £2,816.

What’s more, if your loved one is planning a move to a residential care home but has more than £23,250 in savings - they will be exempt from receiving any financial help.

The overall cost of a care home can be more expensive, depending on where you’re located and the type of care chosen. Alternatively, if you were to secure a live-in carer, you’ll need to pay approximately £150 a day for around-the-clock care.

A fitted kitchen and open plan lounge with settee and chair in a granny annexe

With a granny annexe, you’ll only have to pay for the project. You may also have the opportunity to save on paying out for additional support or professional carers, as you’ll be able to tend to your loved one much more frequently.

So, where finances are concerned, if you’re looking for a less costly alternative to ensure your relative has the care and comforts they deserve in their old age, a granny annexe is a superb long-term solution, the costs of which can often be recouped within a couple of years whilst also adding value to your property as mentioned previously.

You’ll get to spend more time with your loved one

Financial considerations aside, a granny annexe will allow you to spend more time with your elderly loved one, which of course, is priceless.

For many of us, life can get pretty hectic and consuming. Juggling work and personal commitments can sometimes feel like a balancing act, which may mean you can’t visit your loved one as frequently as you’d like. This has been a particular problem for some people during the recent pandemic where access to relatives in care was severely restricted.

Time is precious. And with a granny annexe, you’ll have much more time to spend with your relative, enjoying the activities you love to do as a family and creating invaluable memories to cherish.

Granny annexes can be customised to suit the needs of your elderly loved one

Another positive aspect of a granny annexe is if your elderly relative has additional requirements concerning their care or they’d simply like to put their own stamp on their new living quarters, this type of solution can be adapted and customised to suit.

For instance, it may be that your loved one is a wheelchair user and requires a larger bathroom to ensure accessibility isn’t an issue, or you need more lounge or bedroom space for instance where you are accommodating an elderly couple.

With the right provider, anything is possible. And at Rubicon, we’re proud to say that we offer a bespoke garden room service, which has allowed us to build many one-of-a-kind projects over the years. If you’re interested in seeing some of our previous projects, click here to check out our case studies page.

Your loved one will still have independence

For our elderly relatives, it can be daunting to think about moving out of the homes they’ve known and grown accustomed to for many years. They may worry about losing their independence, and wonder what life will be like for them in the future.

A granny annexe is widely considered a great compromise that helps elderly relatives to transition to being slightly more dependent - without losing their independence entirely. They’ll have access to their own space and privacy, whilst also being able to reach you for help at a moment’s

Modern granny annexe with composite cladding, designed as an Annexe Style Bespoke by Rubicon Garden Rooms adjacent to an outdoor swimming pool.

Click here for more information about our bespoke garden rooms

Discover annexe garden rooms with Rubicon

At Rubicon Garden Rooms, we’re proud to work on bespoke garden-building projects and offer a diverse range of premium garden rooms, offices, and annexes.

Our friendly team can help you create the perfect granny annexe garden room, so feel free to contact us today to find out more or visit our showroom for an in-person chat.

You may be wondering, what are the benefits of choosing Rubicon Garden Rooms? See below for the main reasons our customers choose us:

  • We offer 20-year guarantees (T&Cs apply) with our projects, perfect for those who require peace of mind with their investment.
  • We offer low-maintenance and hassle-free composite cladding to create long-lasting and durable garden rooms.
  • We’re a family-run business established in 2006 that puts our customers first.
  • Our friendly and experienced team are DBS checked and trained to an extremely high standard.
  • We travel far and wide and cover a vast range of areas across the UK.
  • We take pride in our work and deliver exactly what we promised.
  • We offer a fast turnaround time, with the average build taking only 2 weeks to complete for a garden room or 4-6 weeks for an annexe.
  • Customer service is our top priority. We’ll listen to exactly what you want to achieve and take care of everything from start to finish.
  • We offer custom projects for those wanting to create something truly unique.

For a free, friendly consultation, contact Rubicon today, and we’ll be happy to discuss your garden office project

For more garden room information, inspiration and advice, read the Rubicon blog