Granny Annex and Garden Outbuilding

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Transform Your Garden with Eco-Friendly Elegance: The Bio-SIP™ Granny Annex and Garden Outbuilding

In the idyllic setting of your garden, imagine a space that seamlessly blends comfort, sustainability, and a touch of modern design. Welcome to the era of garden living with our Granny Annex and Garden Outbuildings, expertly crafted from the revolutionary Bio-SIP™ Sustainable Modular Building System. This is not just an addition; it’s a haven designed for modern living, where functionality meets environmental responsibility.

Granny Annexe: A Guide to Modern Living:

A Granny Annexe, also known as a garden annex, is more than a simple outbuilding—it’s a carefully designed space tailored for modern lifestyles. The term “annexe” conveys the idea of an additional structure attached or near to the main house, providing an independent living space. These garden annexes are particularly popular for accommodating elderly relatives, hence the affectionate term “Granny Annexe.”

The Perfect Harmony: Granny Annexe and Bio-SIP™ System:

Imagine a Granny Annexe or garden outbuilding that not only extends your living space but also champions sustainability. With the Bio-SIP™ Sustainable Modular Building System, we have redefined the concept of garden living. Our structures, crafted from Our Bio-SIP™ to, ensure not just durability and safety but also a reduced environmental footprint.

Permitted Development Outbuildings:

Our Granny Annex and Garden Outbuilding align seamlessly with permitted development regulations, making the expansion of your living space hassle-free. These structures, designed with an emphasis on sustainability, allow you to enhance your lifestyle while staying within the guidelines of permitted development outbuildings.

Versatile Living Spaces:

The dimensions and design of our Granny Annex and Garden Outbuilding are tailored to cater to diverse needs. Whether it’s a cozy space for an elderly relative, a serene home office, or a private retreat, the versatility of these structures makes them ideal for various functions. The Bio-SIP™ system ensures that each space is not just functional but also environmentally conscious.

Modern Design Meets Sustainability:

Step inside the Granny Annex or Garden Outbuilding, and you’ll be greeted by a modern design that seamlessly integrates with sustainable living. The Bio-SIP™ system incorporates rapidly renewable natural fibers, such as hemp or flax, actively sequestering 160% of their weight in CO2 emissions. This commitment to sustainability ensures that your garden living space is not just aesthetically pleasing but also eco-friendly.

Annex Building for Modern Lifestyles:

Our Annex Building, manufactured with the Bio-SIP™ system, represents a harmonious blend of traditional warmth and modern design. The tongue and groove method used to join Bio-SIP™ panels not only ensures a structurally sound building but also streamlines the construction process, allowing for a quick and efficient assembly.

Perfected for Every Generation:

More than an outbuilding, our Granny Annex and Garden Outbuilding become a cherished space for every generation. From providing a haven for elderly relatives to serving as a contemporary retreat for younger family members, these structures are designed to evolve with the changing needs of your family.

An Investment in Sustainable Living:

Choosing a Granny Annex or Garden Outbuilding made with the Bio-SIP™ Sustainable Modular Building System is more than an investment in additional living space—it’s an investment in sustainable living. By embracing eco-friendly construction practices, you not only enhance your lifestyle but also contribute to a greener, more sustainable future.

In the spirit of modern living and sustainability, our Granny Annex and Garden Outbuilding, crafted with the Bio-SIP™ Sustainable Modular Building System, redefine the concept of garden living. Elevate your lifestyle with structures that not only meet your needs but also champion environmental responsibility. Join us in creating garden spaces that are more than annexes—they are legacies of modern, sustainable living for generations to come.



Materials / Info Description / Insulation Thickness UValue
External Size


Internal Size


Sustainably Built Eco and Bio Yes, recycled materials, natural fibers & Longer life
Roof insulation Metal SIP PIR (Polyisocyanurate) 120mm 0.18 W/M2k
Floor insulation Bio-Sip PET (polyethylene terephthalate) 100mm 0.27 W/M2k
Wall insulation Bio-Sip PET (polyethylene terephthalate) 150mm
0.18 W/M2k
Overall wall thickness 190mm
Internal finish Natural Fiber  panel unfinished 3mm N/A
Floor bearers Wood C24 grade treated FSC 80mm N/A
Window / Doors uPVC or aluminium White or upgrade to colour 40mm 1.7 W/M2k
Double glazing Toughened glass Argon gas filled 25mm 1.4 W/M2k
Guarantee 25 years Structural and components
Life expectancy 50+ years Some maintenance will be needed
DIY installation of building 16 hours 3 competent people
DIY foundation 9 Hours Depend on ground conditions
Delivery 5 day courier Flat packed on pallet


We recommend using a 3rd party base from any of the following providers:

StopDigging EasyPad EcoBase


If you are unsure which type to go for we can run through this with you in a call. Call us now on 01483 346070.

Why buy from us?


We offer guaranteed peace of mind with our 25 year guarantee on all modular buildings

Easy Assembly

Your kit will arrive ready for assembly. No Specialist tools required 

Quick Assembly

Our modular buildings screw together in around 9hrs


All Materials used in Qube Buildings are made from fully recycled or organic compounds

Made in the UK

All manufacturing and building is carried out in the UK for faster delivery and lower CO2 

FREE Survey

Discuss your specific needs with us before you place your order

Composites UK Member

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