As the cost of care homes continues to rise and multi-generational living arrangements become more common, many families are turning to granny annexes as a practical solution. Whether it’s to provide independent living for an elderly family member, a young adult, or even a guest space, these structures offer both flexibility and comfort.

But when choosing between portable granny annexes and permanent structures, the decision isn’t always straightforward. Understanding the pros and cons of granny annexes in both forms can help you make an informed choice that suits your lifestyle, budget, and long-term goals.

For expertly designed annexes tailored to your needs, Timberlogbuild Ltd offers portable and permanent options built with care, comfort, and quality.

Call us on 01622 938100/07538 678629 or drop us an email at today!

Looking to add a granny annexe or permanent living space to your property? Trust Timberlogbuild Ltd for high-quality, tailored solutions built to last.

Understanding The Basics: Portable Vs Permanent

Portable granny annexes, often considered mobile homes, are usually designed to comply with the Caravan Act, meaning they can be placed on a property without full planning permission in some cases. These units are pre-fabricated off-site and delivered to your garden, ready to use.

On the other hand, permanent structures are fully integrated buildings fixed to the land. They are treated like any separate dwelling, require a more rigorous planning application process, and meet all necessary planning and building regulation standards.

Key Considerations Before Deciding

Whether you’re leaning towards a garden annexe, you can move or a solid extension to your property, here are a few things to consider:

  • Who will live in it? A portable unit may be ideal for a temporary or semi-permanent living arrangement. A permanent annexe might be better for a family member needing lifelong support.
  • Budget: Consider the upfront cost and additional costs like groundwork, utility connections, and permissions.
  • Usage: Will it be a full-time home or an occasional guest space? Permanent units suit year-round use better.
  • Regulations: Stay informed about granny flat regulations in the UK, especially if you’re in a conservation area or planning greenbelt development.

Pros And Cons Of Portable Granny Annexes

1. Pros

  • Cost-effective: The cost to build or install a portable annexe is generally lower than a permanent structure. You can save significantly on labour, materials, and site preparation.
  • Speedy setup: Portable units are often delivered as ready-made modules. This means less disruption on-site and a much quicker installation.
  • Planning flexibility: Thanks to the Caravan Act, these units may not require full planning permission, simplifying the process for homeowners.
  • Relocatable: Many portable annexes can be removed or sold if you move or decide the unit is no longer needed.

2. Cons

  • Durability: These units have a shorter lifespan than traditional builds and may require more frequent cabin maintenance.
  • Design limitations: Portable units often come with fixed layouts, limited material options, and reduced insulation compared to a permanent structure.
  • Property value: While they add usable space, portable granny annexes might not contribute as significantly to your property’s resale value.

Pros And Cons Of Permanent Structures

1. Pros

  • Longevity and durability: A well-built permanent annexe is designed to last. With brick or timber frames and firm foundations, these structures offer long-term reliability.
  • More space and freedom: Homeowners can choose fully tailored floor plans, finishes, and features. A single-storey annexe can be customised to include multiple rooms and functional layouts.
  • Added property value: Permanent annexes are more likely to boost your home’s overall market value, especially when built to high standards.
  • Comfort and efficiency: With better insulation and integration into the existing home systems, permanent structures often offer more efficient heating and comfort.

2. Cons

  • Higher cost: Building a granny annexe as a permanent structure is usually higher than a portable unit, especially considering foundation work, plumbing, and electrical systems.
  • Longer timelines: Building a permanent annexe can take several months, from securing permissions to construction.
  • Planning permission required: Most permanent builds require a complete planning application and must meet granny flat regulations in the UK, which can vary depending on your local council.
  • Time-consuming: From design to build, the process can take several months.
  • Planning required: Full planning application and adherence to granny flat regulations in the UK are needed, which can be complex depending on local councils.

Contact Timberlogbuild

    Did you know that we can organise a Lawful Development Certificate for your project?

    Conclusion: Choosing The Best Option For Your Needs

    Both portable and permanent granny annexes have their advantages and disadvantages. Your decision should be based on your budget, long-term plans, local regulations, and who will use the space. Portable options offer speed, flexibility, and affordability, while permanent structures provide comfort, customisation, and long-term value.

    Professional advice ensures compliance and quality when considering a cosy granny flat or a fully equipped garden annexe.

    Looking for the perfect solution? Timberlogbuild Ltd offers expert craftsmanship in portable and permanent annexes—helping families create safe, stylish, and functional spaces to meet every need.

    Contact us today!

    FAQs

    1. Is a Granny Annexe a good idea?

    Yes, a granny annexe offers flexible, independent living for family members and can add value to your property if planned well.

    2. Do you pay council tax on an annexe in the UK?

    Yes, but if a family member lives there, a 50% discount often applies. Sometimes, you may be exempt altogether—check with your local council.

    3. What are the disadvantages of a granny flat?

    Disadvantages include high upfront costs, planning restrictions, and possible additional maintenance or council tax obligations.

    4. Do I need planning permission for a granny annexe in my garden in the UK?

    In many cases, yes—especially for permanent structures. Some mobile homes may be allowed under the Caravan Act but always check with your council.