Modern life demands flexible spaces. Families are growing, lifestyles are changing, and many homeowners are seeking cost-effective ways to add value to their properties without the upheaval of moving house. For many, the solution is a garden annex—a beautifully designed, fully habitable outbuilding that provides extra living space, independence, and comfort.
At Qube Buildings, we specialise in creating high-quality garden annexes tailored to your needs. Whether it’s a compact studio, a one-bedroom retreat, or a spacious two-bedroom home, our annexes offer a smarter, more affordable alternative to a traditional extension.
Why Choose a Garden Annexes?
A Smarter Alternative to Extensions
Extending your home can be disruptive, expensive, and time-consuming. Foundations need to be dug, walls knocked down, and weeks of dust and disruption follow. In contrast, a garden annex is a standalone building—constructed with precision and minimal interference with your main home.
- House extension costs: £90,000–£220,000+
- Qube Buildings garden annex costs: From £50,000–£120,000
Not only are annexes often cheaper, but they also deliver turnkey solutions in a fraction of the time.
A Space That Adapts to Your Lifestyle
Garden annexes aren’t just extra rooms; they are independent living spaces. This flexibility makes them ideal for:
- Elderly relatives who want to live close by but maintain their independence.
- Young adults stepping into independence without high rental costs.
- Guest accommodation that offers privacy for visiting friends and family.
- Rental potential (subject to planning and local regulations).
- Home businesses where you need a professional, separate working space.
Fast, Hassle-Free Construction
Our Bio-SIP™ garden annexes are designed for efficient assembly. Most builds are completed in a matter of weeks, so you can enjoy your new living space sooner, without months of disruption.
Types of Garden Annexes
Every family has different needs. That’s why we offer annexes in various sizes and layouts.
Studio Annexes
Compact, stylish, and self-contained, a studio annex is a perfect entry-level solution. With an open-plan living and sleeping space, kitchenette, and bathroom, it’s ideal for single occupants or as a guest suite.
- Typical size: 20–30m²
- Best for: Lodgers, students, or short stays.
One-Bedroom Garden Annexes
Offering greater privacy and comfort, a one-bedroom annex includes a separate bedroom, making it suitable for long-term living. This option is popular with elderly parents or young couples.
- Typical size: 30–45m²
- Best for: Independent living for one person or couples.
Two-Bedroom Garden Annexes
The largest option, a two-bedroom annex functions as a genuine small home. With bedrooms, a living area, bathroom, and kitchen, it provides independence and comfort for family members or tenants.
- Typical size: 45–65m²+
- Best for: Families, carers, or rental use.
Planning Permission: What You Need to Know about Garden Annexes
Outbuildings Under Permitted Development
Not all garden buildings need planning permission. Simple offices, gyms, or summerhouses often fall under permitted development rights—provided they meet certain size and placement restrictions.
When Permission Is Required
If your annex includes bedrooms or sleeping accommodation, planning permission is usually required. Local councils consider these habitable dwellings and assess them for:
- Impact on neighbours (privacy and scale).
- Access and services (drainage, electricity, water).
- Design and appearance (sympathetic to surroundings).
We guide clients through the planning process, ensuring your annex is compliant and fully approved before construction begins.
Key Design Features of a Bio-SIP™ Garden Annexes
Comfort All Year Round
Our annexes are built with high-quality insulation and glazing, ensuring they’re warm in winter, cool in summer, and efficient to run.
Stylish Interiors
From sleek studios to spacious two-bedroom homes, every annex is tailored to your design preferences, with modern finishes, fitted kitchens, and smart bathroom layouts.
Efficient Services
All annexes can be connected to your property’s utilities, with professional installation of plumbing, electrics, and heating systems for a seamless finish.
Future-Proof Design
Whether you’re planning for ageing relatives, growing children, or a home-based business, our annexes are designed to evolve with your needs.
Cost of a Garden Annexes
The price of a Qube annex depends on its size, design, and specification. As a guide:
- Studio annex: £40,000–£55,000
- One-bedroom annex: £75,000–£95,000
- Two-bedroom annex: £95,000–£110,000+
When compared with the cost of moving house or building an extension, garden annexes often prove to be the most economical and least disruptive solution.
Benefits Beyond Space
Increased Property Value
A well-designed annex is an asset. Homes with annexes often appeal to buyers looking for flexible, multi-generational living arrangements.
Multi-Generational Living
Annexes allow families to stay close while preserving independence. This arrangement saves money, strengthens relationships, and provides long-term security for both older and younger generations.
Lifestyle Flexibility
An annex today might house your parents, but in five years it could be your teenager’s retreat, a holiday rental, or your new home office. The possibilities are endless.
Challenges to Consider for Garden Annexes
While garden annexes bring huge benefits, there are some considerations:
- Planning restrictions in conservation areas or urban settings.
- Initial investment costs, though often offset by long-term value.
- Utility connections which may require groundwork.
- Council use conditions – most annexes must remain ancillary to the main home.
Our team at Qube Buildings helps you navigate these challenges with expert advice and tailored solutions.
Why Choose Bio-SIP™ for your Garden Annexes?
At Bio-SIP™ we pride ourselves on delivering affordable, high-quality annexes that transform outdoor space into fully functional homes. With a focus on modern design, efficient construction, and long-lasting performance, our garden annexes are built to add value to your lifestyle and your property.
From initial consultation through design, planning, and construction, we handle the process end to end, making it stress-free for our clients.
A garden annex is more than just an outbuilding—it’s a life-enhancing investment. Cheaper than a house extension, quicker to build, and adaptable for countless uses, annexes are becoming a popular choice for families across the UK.
Whether you need a compact studio, a one-bedroom retreat, or a spacious two-bedroom home, Bio-SIP™ delivers annexes that combine affordability, flexibility, and quality construction.
For families seeking independence, investors looking to add value, or homeowners wanting more space without moving, a Qube annex is the smart solution.