How Much Would It Cost To Build A Granny Annexe?

James Bowdler

13 September, 2023

2 min read

On average, it can range from £68,000 to £140,000. A higher-end, fully fitted annexe can cost up to £150,000, while a basic model can start around £50,000.

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Key Factors Influencing Cost

When considering how much it will cost to build a granny annexe, it’s important to remember that numerous factors can influence the final price. We’ll discuss some of the most significant ones here.

Size of The Annexe

One of the most significant factors affecting the cost is the size of the granny annexe. A larger building naturally requires more materials, labour, and potentially more expensive groundwork.

Type of Construction

The type of construction used for the granny annexe will substantially affect the cost. Traditional brick and block annexes tend to be more costly, while timber-framed ones may be cheaper. Bespoke, luxury annexes built with high-end materials could push the cost far higher.

Groundwork and Site Access

The condition and accessibility of your site can also add to the total price. Preparatory work, such as dealing with uneven ground, removing trees, or accessing hard-to-reach back gardens, can add unexpected expenses.

Plan Approval

Not forgetting that planning permission might be required, and this process can be costly. Professional fees might include hiring an architect or a planning consultant, and these fees can quickly add up.

Breakdown of Potential Costs

It is difficult to pinpoint exactly how much a granny annexe’s construction will cost without first acquiring detailed plans and quotations. However, we can provide a general guide to potential costs.

Base Build and Construction

Based on an average of prices across the UK, for a basic granny annexe of about £40m^2, you can expect to pay around £59,000 – £84,000 for the base build and construction. This cost includes base groundwork, structure build, complete interiors, lights, electric connection, plumbing, heating, ventilation, bathroom, kitchen fitting, and painting and decorating.

Architectural Plans

Professional drawings for the planning application and structural engineering drawings are crucial. The average cost for the entire design process usually falls between £2,500 – £5,000. This price usually includes preparing and submitting the planning application.

Planning Permission

Planning application fees alone cost around £172 for an annexe that falls within the permitted development guidelines. However, if full planning permission is required, this cost might increase to about £462.

Utility Connection Fees

Connecting the annexe to mains electricity, water, gas, and sewage can cost anywhere from £1,500 – £3,000. These prices largely depend on the distance from the main property to the granny annexe.

Conclusion

Building a granny annexe is no small expense, but the potential benefits can far outweigh the cost. It allows elderly relatives to live close by, retaining their independence while giving the rest of the family peace of mind. However, like any major home improvement project, it is important to budget effectively and understand the potential costs.

Remember that the costs mentioned in this article are approximate and may vary depending on numerous factors. Getting quotes from several professional builders is recommended to get a clearer idea of the potential cost for your specific project.

At PrimeCarers, we understand that caring for elderly relatives can be expensive and time-consuming. That’s why we strive to match private home carers with clients, ensuring your loved ones receive the best care possible. Feel free to contact us if you need any further advice or support related to home care options.

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James Bowdler

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I founded and manage PrimeCarers, a Platform that connects Private Clients with Private Carers near them.

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