Garden Rooms > The Annex > The Den
About The Den
from £75,900 fully inclusive
see customer reviews >
- Caravan Act Compliant
- Studio or one bedroom
- Available in 10 size configurations
What’s included v See Specification v
The Den is a sleek and compact annex designed under Caravan Act legislation, meaning it can be built in most cases without planning permission.
This annex design has a simple and modern appearance, created through its flat front and straight lines, without a front hood, to achieve a more streamlined look. The smaller external footprint makes this annex ideal for smaller plots or simpler needs, while still offering practical living space with elegant styling, all delivered with ease and efficiency.
Our Caravan Act annexes are manufactured to be ‘moveable’, with the floor panels sitting within a steel chassis, which sits on top of ground screw piles. There are no wheels like a traditional static caravan, making The Den feel more like a modern and contemporary home.
Available in ten versatile size options, The Den can be configured to create a comfortable garden house.
The Den Annex Pricing Table
Prices include: VAT, professional installation, base and foundations, delivery* and a fully insulated turnkey specification designed for modern living.
External/Internal Sizes
| D W |
|---|
| 3.8m |
| 7.7m | 8.2m | 8.7m | 9.2m | 9.7m | 10.2m | 10.7m | 11.2m | 11.7m | 12.2m |
|---|---|---|---|---|---|---|---|---|---|
| £75,900 | £80,065 | £84,235 | £88,400 | £92,570 | £96,735 | £101,090 | £105,445 | £109,795 | £114,150 |
Let us come and measure...
The Annex Transparent Pricing Policy:
- All listed prices are fully inclusive, with all essentials included. What’s included >
- Quoted sizes are EXTERNAL measurements for simple and transparent sizing.
- Premium materials come as standard.
What’s included as standard
with The Den Annex
- Full measurements and site survey
- Full building installation
- Ground screw foundations
- 12-year guarantee
- 2.3m high-security uPVC French, sliding or entrance door
- Fire safety opening window
- Premium double-glazing throughout
- 10m of plumbing
- 20m of electrical connection
- Standard fitted kitchen
- Standard fitted bathroom
- Insurance-grade locks throughout
- High-performance insulation for year-round use
- Roof surface in maintenance-free coated steel
- Exterior Redwood cladding
- Interior walls in soft-sheen white melamine
- Wall-mounted radiator
- Internal LED Lighting
- External lighting
- 8 internal double sockets
- Oak laminate flooring
Annex Offer
£2,000 Voucher towards your order
Be one of the next 10 customers to place an order and receive a £2,000 voucher to spend on options and upgrades - the perfect way to personalise your new garden home.
*TERMS AND CONDITIONS APPLY
- The £2,000 discount is available on the next ten annexe building orders only.
- This promotion will end automatically once ten qualifying orders have been secured.
- The promotion cannot be used in conjunction with any other offer.
- The promotion cannot be used in conjunction with finance applications.
- Valid for new orders on the latest pricing version only.
- We reserve the right to withdraw, modify, or suspend any promotion, or amend these terms and conditions at any time without notice if it becomes necessary to do so.
Does ‘The Den’ Annex need planning permission?
In most cases, The Den annexe will not require planning permission as they are built to be Caravan Act Compliant, which means they are not classed as permanent buildings.
Because of the Caravan Act classification, they usually don’t need planning permission when sited in a domestic garden for use ancillary to the main house (e.g., for a family member) — although they may still need a Certificate of Lawfulness from the council to confirm it’s exempt.
If you do require a Certificate of Lawfulness or full planning permission, we have a dedicated in-house planning team to handle the process on your behalf.
About Our Annexes
What’s the difference between Caravan Act and Building Regulations annexes?
Building Regulations annexes are permanent structures built to full UK Building Regulations standards. They require planning permission as they create a new dwelling space and must meet strict rules for insulation, safety, drainage, and more. These buildings offer the widest range of sizes, layouts, and customisation options.
Caravan Act annexes, while often looking like modern permanent homes, are legally classed as moveable structures because they are built in transportable sections. This means they typically don’t require planning permission when used alongside the main house, though a Certificate of Lawfulness is sometimes needed. They are generally quicker and more cost-effective to build, but have some size and layout limitations.
Despite the name, Caravan Act annexes aren’t touring caravans and don’t have wheels — they are contemporary, high-quality buildings designed to look and feel like a permanent home.
What’s Included with The Den Annex?
Fitted Bathroom
Fitted Bathroom
A choice of 3 bathroom layout designs, all of which include:
- Vanity unit sink
- Extractor fan
- Heated towel rail
- Aqualisa shower
- Low profile shower tray
- Soft close toilet
- A choice of decorative finishes.
Plumbing
Plumbing
The plumbing setup in the annex building include up to 10 meters of cold-water piping, complete with connections at both ends, ensuring convenient access to water throughout the space. Similarly, up to 10 meters of foul piping, also with connections at both ends, efficiently manages wastewater disposal. A soakaway is included to facilitate proper drainage and water dispersal.
Melamine Interior Finish
Melamine Interior Finish
The Den comes with white interior melamine walls as standard, which is easy to clean and soft to the touch. Plastering and painting can be added as a costed upgrade.
Fitted Kitchen
Fitted Kitchen
You can choose from two standard options for your annex kitchen. You can opt for a straight unit or an L-shaped kitchen. Both options include:
- A full-height 70/30 fridge/freezer
- Full induction hob
- Sink with a draining board
- Slide and hide single oven and an extractor hood
Heating
Heating
As standard and included in the price of your building are wall-mounted energy-efficient heaters, with at least one in each room or more for larger rooms if needed (calculated at the electrical plan stage). If you prefer, you can upgrade to air conditioning units or underfloor heating.
Full Electrics & Connection
Full Electrics & Connection
Our annexes come with a variety of electrical components designed to elevate both functionality and comfort. All annexes come with 8 double recessed plug sockets conveniently placed around the building to provide accessible electrical points to power multiple devices.
Ground Screw Foundations
Building Foundations
The Den floor panels sit within a 207mm steel chassis, which sits on top of ground screw piles. These buildings do not have wheels like a caravan.
Professional Installation
Professional Installation
Our annexes include professional installation performed by our skilled and experienced teams. Rest assured, your annex will be expertly assembled and finished according to the exceptional standards synonymous with Green Retreats.
Internal & External Lighting
Internal & External Lighting
We offer a mixture internal and external lighting options to suit your preferences. Plus, our package includes a 2-way consumer unit (fuse box), providing peace of mind knowing that your electrical system is efficiently managed and protected.
2.3m French, sliding or entrance door
2.3m French, sliding or entrance door
Our annexes feature 2.3m French, sliding or entrance door as standard. These doors offer abundant natural light and easy access, elevating your annexe’s style while seamlessly fitting into the design.
Redwood Cladding
Redwood Cladding
Our Scandinavian redwood cladding is responsibly harvested and FSC-certified, guaranteeing sustainability. This low-maintenance wood, aged over 80 years, boasts enhanced natural resilience; it’s fortified against weathering and wear, ensuring lasting quality and beauty.
12-year guarantee
12-year guarantee
Our garden annexes come with a 12-year guarantee, providing you with peace of mind and confidence in the quality and durability of your investment. Our dedicated aftercare team are on hand after your installation for any questions, queries or advice you need around your new home.
Escape Window
Escape Window
One escape window is included as standard in your annexe building.
Laminate Flooring
Laminate Flooring
Choose from our laminate flooring colours: light oak, dark oak, or grey oak.
Click each feature for more information and specifications
How is The Den Annex constructed?
Roof Section
Crafted from a blend of epoxy resin, steel, and high-density foam insulation, the annex roof section embodies modern innovation and durability. The high-density foam insulation ensures superior thermal performance, while the steel framework provides structural integrity and support against heavy loads and harsh weather. The roof section is encased in epoxy resin and boasts a seamless, waterproof barrier, ensuring long-term durability and protection.
Wall Section
The annex wall section is a fusion of materials designed for functionality and aesthetics. It starts with durable exterior cladding and cavity batten for ventilation. Photon wrap adds weatherproofing and insulation, while insulated fireproof cement board ensures safety and stability. Cable trunking keeps wiring concealed, and an insulated panel enhances thermal performance. Finally, plasterboard offers a smooth finish for interior decoration. This combination creates a secure, comfortable, and visually pleasing living space.
Floor Section
In the design of a modern annex floor, laminate flooring, steel beams, and high-density foam insulation combine seamlessly for both functionality and aesthetic appeal.
Laminate flooring provides durability and elegance, mimicking the look of natural materials while resisting scratches and stains. Steel beams offer structural strength and stability, efficiently distributing weight and withstanding environmental factors like moisture. High-density foam insulation regulates temperature and reduces noise transmission between floors, ensuring comfort and tranquillity.
Payment Schedule
£2,500 Deposit
Your deposit will secure your installation date as well as cover the cost of the technical survey, ground screw test and certificate of lawfulness application. The ground screw test may be carried out as a first step. *
60% of Remaining Balance 8 Weeks Before
Eight weeks before your project start date, we will contact you to finalise any options and take a further 60% payment.
30% of Remaining Balance on Completion of Groundworks
Groundworks for your building will be scheduled shortly before your building is due to be installed. At this point, we will ask for a further 30% payment of the balance.
Final Balance on Completion
Once your building is complete, we will ask you to sign off on the work. After you have signed off on your building, the remaining 10% balance will be due to be paid.
How to Order Your Annex
Pop Into Our Showroom
Are you starting your annex journey? We recommend coming and seeing our buildings in person to place an order. This way, you can browse and explore our entire range with the help of our friendly team, who can answer all your questions and take payment in the showroom.
We’ll Come to You!
Already know what you want? If you’re happy with your online research without visiting our showrooms, you can book an at-home design consultation.
At this appointment, we will review all the important design elements and measurements for your project. The design consultation is completely free with no obligation and place your order with our sight surveyors.
Annex Ideas Gallery
Tiny homes made for full time living.
Caravan Act Buildings
Fully insulated wall, floor, and roof sections create a warm, durable home all year round.
Wall
1. Soft-Sheen Laminated Interior Wall
2. Rockwool Insulation 100mm
3. Photonwrap
4. Cavity Gap
5. Exterior Cladding
Roof
1. Epoxy Resin Coated Steel
2. High Density Foam
3. Steel
Floor
1. Steel Laminated High Density Foam
2. Underlay
3. Laminate Flooring or Carpet
The best place to compare?
Visit our Buckinghamshire Showroom
See the differences between the ranges for yourself, and experience the quality in person.
Our Showrooms
What our customers say
We are so pleased to be top rated on Trustpilot
by our customers.
by Louisa (Louisa Tudor)
Fantastic Room in a little London garden!
We now have an amazing room at the bottom of our garden that fits in beautifully and feels as though it has been there for ever. All the staff were incredibly helpful and friendly and the entire process was very straightforward.
by Peter
Can’t beat a Green Retreat!
We cannot recommend Green Retreats highly enough, compare their offer to anyone else and I think they will win the day. The finished result is a garden room of class and something to be proud of. Value is what you get as an overall package and experience, not what just the price tag states. Choose low maintenance materials and you cannot do better than Green Retreats, they simply are very hard to beat!
by Mark
I’d recommend them to anyone
Each element of the team that came were all extremely polite, punctual and very professional. The quality of the materials are extremely high and the overall quality of the garden room is amazing. It’s fabulous to be able to sit in a room outside to work and to relax and enjoy the garden to its full potential. Green Retreats have been superb throughout the process, and we would not hesitate to recommend them to anyone!
by Sarah Levin
What a great company!
The customer care and communication, from the start of my enquiry through to the installation has been exemplary! I’m so pleased with my G2, it not only looks great but it is a
first class product down to the last detail. I can’t recommend Green Retreats highly enough and I’m super excited to relocate my art studio into the garden! Thank you Green Retreats.
Annex Quick Quote
Request a quick, no-obligation quote in a few simple steps, and our Sales Team will get back to you as soon as possible.