Insulated Garden Rooms
A Comfortable Garden Room, Whatever The Weather
Our fully insulated garden rooms are designed to be used and enjoyed all year round. Built with high-quality materials and expert craftsmanship, each room offers outstanding thermal performance — keeping you cool in summer and cosy in winter.
With premium insulation in the walls, floors and roof, you can stay comfortable through every season. Whether it’s a peaceful place to unwind, a space to pursue your hobbies, or simply a warm room in winter, your outdoor space becomes a natural extension of your home.
Why Choose an Insulated Garden Room?
All garden buildings from Green Retreats come fully insulated, with double glazing and heating included as standard — creating a space that’s ready for year-round use.
Our thermally efficient garden buildings are perfect for everyday living. Whether you’re setting up a home gym, garden studio, or simply a relaxing retreat, each building is designed to be energy-efficient, low maintenance and made to last.
You’ll enjoy the comfort of a traditional home extension, without the disruption — and with a modern, flexible space that’s tailored to your lifestyle.
About Our Insulation
Walls
Our walls are designed to be both thermally and space efficient to ensures the best u-values and maximum internal space. Our wall thickness is 100mm, which includes 45mm of Rockwool insulation and a scientifically developed thermal vapour barrier called Photonwrap. This allows moisture to escape and it also reflects heat back into your room in the winter months.
See how our insulated garden rooms are made by reading our manufacturing process.
Floor & Roofing
We use structurally insulated 60mm roof panels and 80mm floor panels in our garden buildings. These panels provide decades of life expectancy, outlasting EPDM rubber and felt roofs that are often used by our competitors. Our floor and roof panels also add to our unrivalled levels of insulation, which slot and bolt together quickly, meaning we are on-site for less time, and you can start moving into your new space.
Glazing
Double glazing like you’d find in a residential house in our doors and windows complete the puzzle. We have partnered with Clear Edge uPVC, who are based on the same business park as our Buckinghamshire showroom and factory. Clear Edge and Green Retreats have worked tirelessly to manufacture doors and windows using state-of-the-art machinery and uPVC materials. This partnership allows us to create market-leading double glazing units for insulated garden rooms.
Heating
A wall-mounted radiator (is supplied to you as standard, already included in the price of every building. Due to our superior wall cavity insulation, this oil-filled radiator is more than sufficient to heat our insulated garden rooms in the winter. Effective engineering of our materials means that our buildings are efficient without having to meet costly building regulation standards. We also offer optional upgrades of underfloor heating and even air-conditioning for complete temperature control.
Our U-Values
The u-values of our garden buildings can be found below. Our manufacturing page contains even more information about our construction methods:
- Glazing: U-Value 1.2
- Walls: U-Value 0.31
- Roof: U-Value 0.35
- Floor: U-Value 0.23
Browse Our Range of Insulated Garden Rooms
Cost-effective
Basebox
From £9,995
Our most cost-effective garden room range, designed and built with form and function in mind.
Shop Basebox
The Original
G-Range
From £23,790
Our classic garden room range with a focus on natural materials and modern composites.
Shop G-RANGE
Extra Height
A-Range
From £30,995
Reach new heights with our apex roof garden rooms, where style and space soar.
Shop A-Range
Elevated Luxury
X1
From £49,950
The X1 garden room has been infused with luxury from inception and embedded in every detail.
Shop X1
Garden Houses
by Green Retreats
Living Solution
The Annex
From £63,090
Our collection of tiny homes, designed for full time living, including building regulations approval.
Shop Annex
Christmas Offer
Unwrap your free gift 🎁
This Christmas, take your pick of our exclusive upgrade gift packs and add a little festive magic to your new garden room. Personalise your space with premium finishes, tech and comfort options.
*TERMS AND CONDITIONS APPLY
- Customers ordering a G-Range, A-Range, X1, Basebox or Basebox+ building qualify for one free gift as part of the promotion from the described selection if they book into a qualifying installation date before the end of January 2026.
- Promotional gifts will be removed from the order if the customer cancels their order, or moves their installation date out of a qualifying timeframe, and the customer would be liable to cover any extra costs should the customer choose to keep any building upgrade gift options.
- The ‘Tech Pack’ and ‘John Lewis Voucher’ gifts will be sent to the customer's building installation delivery address on completion of the building installation and once the final balance payment is received.
- There is no gift valid for Basebox Kit or Annex buildings.
- The Free Gift is non-transferable, non-exchangeable, has no cash alternative, and is not for resale.
- You may not qualify for the promotion if you require planning permission and cannot get approval before the qualifying installation weeks.
- The promotion cannot be used in conjunction with any other offer.
- The promotion cannot be used in conjunction with 0% Finance.
- The promotion offer does not apply to orders placed through Costco.
- Valid for new orders on v.25 pricing only.
- We reserve the right to withdraw, modify, or suspend the Free Gift Promotion, or amend these terms and conditions at any time without notice if it becomes necessary to do so.
- The Electrical Connection offer covers cabling up to and including 6mm. Please note that trenching or any additional groundworks required for cable installation are not included.
Benefits Of A Insulated Garden Room
Insulated All Year Round
Our insulated garden rooms are designed to keep you comfortable regardless of season – warm in winter and cool in summer!
Energy Efficient
The superior insulation and double-glazing used in our insulated garden rooms makes them incredibly energy efficient, saving you money on wasted energy.
A Holiday at Home
In need of that mid-week getaway? Our insulated garden rooms give you the perfect space to create your haven at home. Put your feet up and unwind only a few steps away from your front door.
Create Space
Rather than squeezing into a corner of the spare room or taking over the dining table, create a dedicated space to work that also adds value to your home.
Adding Value To Your Home
You can increase your property value by 15% by having one of our insulated garden rooms! This price increase is estimated to be approximately 1.5x the cost of the building. Find out more here…
Eco-Friendly
Our insulated garden rooms are built using sustainable materials, we send no waste to landfills, we’re solar powered, we use FSC-certified timber, and we’re also carbon neutral.
Top 3 Insulated Garden Room Uses
Get inspired by the most popular ways our garden buildings are used, whatever the season.
1. Garden Offices
A fully insulated garden office creates a productive work environment, separate from household distractions. With excellent year-round insulation, heating and double glazing, you’ll stay comfortable and focused in every season. Customise your space to suit your remote work setup or small business needs.
2. Home Gym in the Garden
Reach your fitness goals in a private, purpose-built space. Our insulated garden gyms offer natural light, ventilation, privacy and comfort — making them the perfect year-round space to stay active without leaving home.
3. Garden Guest Room
Welcome overnight guests with comfort and privacy in a fully insulated garden guest room. With heating, lighting and premium insulation included as standard, all you need to do is furnish it — creating a stylish, self-contained space for family and friends.
Insulated Garden Room Gallery
Real Customer Projects
Get inspired for your insulated garden room project!
Why is Green Retreats the UK’s favourite Garden Room Company:
Eco-Friendly & Sustainable
Green Retreats is the eco-friendly choice! As a carbon-neutral company, we plant five trees for every one used. And for our garden room buildings, the energy-efficient insulation protects the environment while saving you money!
Family-Run Since 2005
Since 2005, we’ve been helping our customers grow their homes with insulated garden rooms. We’re tried and tested and remain the UK’s favourite. And we’re very proud!
12-year guarantee
All of our insulated garden rooms come with a comprehensive 12-year guarantee, giving you that extra peace of mind for a lasting investment to your home.
Engineered For Year-Round Use
Every building from Green Retreats is fully insulated for comfortable use all year round. Cavity insulation, double-glazing, and heating are included as standard.
Designed and built in the UK
Every element of our insulated garden rooms is designed and manufactured in-house at our state-of-the-art manufacturing facilities in the UK.
UK’s Largest Garden Room Showroom
We have two showrooms for customers to experience the quality of our buildings for themselves! Including the UK’s largest garden room showroom in Buckinghamshire near Bicester Village.
Add Value to your Home
Our insulated garden rooms have been proven to add value to your home, as much as 5-15%! Our buildings are a lasting investment to your home and lifestyle.
Backed by TV’s Kevin McCloud
Architecture guru and BAFTA award-winning presenter Kevin McCloud has chosen to work with Green Retreats due to our commitment and shared passion for quality design, innovation and sustainability in the construction industry.
Our Showrooms
See the quality of our insulated garden rooms for yourself by visiting one of our showrooms! Choose from our flagship showroom in Buckinghamshire with 21 garden buildings to see or our hub showroom in Twickenham with 4 garden buildings on display.
A lookbook of our insulated garden rooms to inspire your project
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 E Fisher (Diva Fitness)
Excellent choice of supplier for my Garden Studio! So pleased
Green Retreats deserve every single one of my star ratings! They have been very professional right from the start, from welcoming me to their warehouse to helping me make the right choice through to a fabulous installation. The finished studio is amazing, a top quality build and the installation teams were timely, polite and very hard-working.
Thanks to you all…what a fab company!!
by Alexa Garthwaite
Fantastic product and service to match
We had a 3.5m by 5m garden room installed last month and we are delighted with the result. We are using it as a home gym and love the extra space it has given us! The building also looks fantastic at the bottom of our garden. Green retreats have been an absolute pleasure to deal with. In summary I have been very impressed by both the product and the service provided by green retreats and highly recommend!
Insulated Garden Room FAQs
The great news is that planning permission is generally not required for insulated garden rooms! Insulated garden rooms are classed as ‘outbuildings’, which fall within your permitted development rights. Some properties and areas in the UK don’t have permitted development rights, in which case planning permission would be required. We can help with the planning application process on your behalf should you need it, taking care of the hassle for you.
Absolutely! Independent property experts have calculated that quality insulated garden rooms can add between 5-15% on your property value! In addition, Luke Jackson, a property expert, noted: “With remote working now so common, buyers’ priorities have shifted. An insulated garden room, separate from the main house, can now be the deciding factor in closing a property deal.” Find out more about how garden rooms add value to your home…
The lower the u-value the better a material is at reducing thermal transfer, so keeping the heat in and the cold out! We have these measurements for our individual materials to give you an idea of just how efficient our buildings are! Each building is custom made to your specification (size, number of windows etc) so the total u-value of each building will differ. However, because we use premium materials to keep our insulated garden rooms warm you won’t need to worry about feeling the outside elements.
Garden rooms are perfect for occasional use, so the odd overnight stay – whether it’s a guest visit or a fun sleepover – is usually no problem at all.
With full insulation and heating included as standard, these spaces are warm, cosy, and comfortable throughout the year. However, most garden rooms aren’t intended or approved for full-time residential living. If you’re planning to use one as permanent accommodation, you’ll likely need to explore planning permission and meet specific building regulations.
Absolutely. Our buildings are fully insulated in the walls, floor and roof, with heating and double glazing included as standard – making them comfortable whatever the season.
The cost of an insulated garden room depends on the size, design and any optional upgrades you choose. At Green Retreats, our fully insulated garden rooms start from £11,732, including installation, foundations, heating and double glazing as standard — with no hidden costs.
Every building is made to order, so you’ll only pay for the features you need. You can get an instant estimate with our Quick Quote tool or visit our showroom to explore your options.
We're Proud to Have Worked With
As the UK’s leading garden room company, Green Retreats are proud to have been featured in many national publications.
Case Studies & Ideas
Looking for some inspiration for your insulated garden room? Take a look at what some of our customers have done with their Green Retreat.
