Skip to content

Free Pick a Day Delivery within the UK

By Marketing Mercia on

Buying Guide - Insulated Garden Rooms

  • buying guide
  • insulated garden rooms
Buying Guide - Insulated Garden Rooms

Insulated garden rooms offer a quick, easy, and cost-effective alternative to a home extension. Enjoy usability throughout the year with these premium buildings which stay cool in summer and warm in winter, making them a practical and functional space for any purpose. Whether you’re planning on transforming yours into a home office, entertaining space or perhaps a personal gym, these premium buildings are designed for versatility to suit your family’s needs.

1. What is an Insulated Garden Room?

As Mercia’s most premium product range, insulated garden rooms provide year-round usability, complete with exquisite features and details that will elevate your space.

Shiplap+ Cladding

Used for exterior wall panels, Shiplap+ cladding is manufactured using strong and thick 16mm interlocking tongue and groove boards that offer an unparalleled finish. The unique design gives the boards added support for strength and weatherproofing, creating a tight seal against wet weather.


All wall panels are insulated using EcoQuilt, a revolutionary foil-coated and breathable foam membrane which, thanks to its minimal thickness, provides plenty of insulation without sacrificing internal space. Providing thermal values equivalent to over 100mm of fibre insulation, this material is assembled with six layers of thermowadding, a breathable foam membrane which also acts as a vapour control layer, and is finished with a coating of highly reflective foil.
As well as wall insulation, all Mercia garden rooms are manufactured with insulation in the floor and roof. This maximises the building’s insulating properties to ensure you can use the building throughout the year, keeping you warm in winter and cool in summer.


Fitted on top of a strong, secure frame, the floors of our insulated garden rooms are made from 16mm tongue and groove board. This robust material is designed to support the weight of furniture and easily withstand daily use, making it the perfect choice for these premium products.


Each garden room is equipped with a solid sheet board roof, clad with 12mm interlocking tongue and groove board on the interior. To protect against wet weather, the roof is covered with high-quality roofing material which extends the life of the garden room.


All garden rooms are supplied with 14mm double-glazed windows and doors as standard. Not only does this provide a greater level of security, it also helps to keep your garden room warm during the cooler months.


2. Why buy an Insulated Garden Room?

 By investing in an insulated garden room, you can enjoy the natural beauty of your garden throughout the year. Take pleasure in the comfort of a warm, sheltered space while staying connected to the outdoors. Moreover, garden rooms are an attractive prospect for potential homebuyers, and can add substantial value to your property.

Designed with versatility in mind, our garden rooms can be easily transformed to meet your unique needs and preferences, creating a personalised sanctuary tailored to you.

Office Space

Make commutes a thing of the past and embrace the work-from-home lifestyle by transforming your garden into a thriving workspace. With the option to install electric power, you can implement everything you need for a productive day’s work. If you plan to utilise your garden room for business purposes, it’s crucial to be informed about planning permission requirements. Ensure compliance with relevant authorities before proceeding to make your work-from-home dreams a reality.

Craft/Hobby Room

If you’ve always dreamed of your own dedicated space to pursue your crafts and hobbies, an insulated garden room is the perfect solution. An abundance of tall windows flood the room with natural light, while the premium insulating properties keep the interior at a comfortable temperature. Whether you’re into painting, sewing, drawing or any creative pursuit, this space offers the ideal conditions for unleashing your creativity. With your very own craft space you can say goodbye to constant clean-up, leaving more time for the things that matter.

Entertaining Space

Don’t let unpredictable weather dampen your garden party plans! Our garden rooms are the ultimate solution, providing warmth, shelter, and comfort to create the perfect space for your next social event. Whether you’re planning an alfresco dining experience, a relaxed gathering at the garden bar, or a fun-filled kid’s birthday party, our versatile garden rooms can be easily adapted to suit all your needs. Say goodbye to weather worries and host your memorable gatherings with confidence!

Living Space

Is your house bursting at the seams? Serving as a cost-effective and non-disruptive alternative to a traditional home extension, our insulated garden rooms provide much-needed additional living space without the hassle. These bright and inviting rooms can easily be converted into a comfortable and relaxing haven, providing the perfect spot to unwind while immersing yourself in the beauty of your garden. Plus, our garden room’s premium insulating properties ensure you can enjoy your extended living space all year round!


3. DIY range

Perfect for those with a good understanding of DIY, these garden rooms offer the same premium quality of our classic range, without the added cost of installation. Our DIY range is available in five convenient sizes to suit every outdoor space. Plus, with its modular design, you have the flexibility to configure doors and windows to your liking, so you can easily adapt your DIY garden room into the living space of your dreams.

Experience year-round comfort with 72mm thick double skinned walls, double-glazed windows, and comprehensive insulation for the roof, floor and walls. The flat roof creates a contemporary silhouette, whilst promoting excellent rainwater run-off. This is then sealed with high-grade mineral felt to help keep your building dry and provide service for many years to come.

4. Classic range

Enjoy the premium quality of our insulated garden rooms with the added convenience of free home installation included as standard! Available in a wide range of different sizes, there is a garden room perfectly suited for every garden and purpose. The sleek contemporary pent roof design offers generous headroom, ideal for accommodating tall furniture. Featuring stylish spotlights, the modern roof overhang connects the interior and exterior spaces, allowing you to make use of your garden even when the evening settles in.

Thoughtfully designed for year-round comfort, our garden rooms are constructed with a fully insulated roof and floor, double-glazed windows and doors, and 72mm thick double skinned walls. Not only does this produce a private, quiet environment, these features also keep the building warm in the winter and cool in the summer. Plus, with high-quality mineral roofing felt to protect against adverse weather, you can be sure that your garden room will stand the test of time.

5. Classic with side shed range

Take advantage of the many premium features included as standard with our classic insulated garden room range, but with the added convenience of a secure storage space! In addition to a spacious new living area, the adjoining storage space offers the ideal environment to keep your garden equipment, DIY tools, and family bikes safely locked away. Plus, with free home installation included, you can sit back and relax while our expert installers bring your dream garden room to life!

6. Sherwood range

Inspired by the local area in which Mercia is based, the Sherwood range is our most premium collection of insulated garden rooms. Fully insulated with 100mm thick double skinned walls, the Sherwood range offers superior comfort all year round. Due to premium construction features such as EPDM rubber roofing material, double-glazed windows and Shiplap+ cladding, these luxurious garden rooms are built to provide years of high-quality service.

With five unique designs to choose from, take your garden to the next level with a garden room perfectly suited to your style and requirements. Each design is modular, meaning you can arrange for the doors and windows to be reconfigured to create your dream home office, hobby room or perhaps home gym. Plus, free home installation is included as standard, so you can relax and unwind while our installation team expertly construct your new garden room.

7. Which garden room is best for you?

Investing in an insulated garden room is a big decision, not only for the present but also for the long term. It is crucial to carefully consider which garden room aligns with your current needs while also anticipating how it can accommodate your future requirements. The grid below outlines Mercia’s insulated garden room collections to help you choose the style, size and design perfect for you.

8. Planning permission and installation

All Mercia insulated garden rooms are designed to meet the official criteria for ‘permitted development’ to avoid the need for planning permission. However, before making any purchases, we recommend verifying with your local planning office for complete peace of mind. Planning guidelines restrict any garden building from occupying at least 50% of your garden without planning permission. For those considering long-term accommodation or the addition of utilities like mains power, water, and drainage, adhering to building regulations is crucial.

All garden buildings must be installed on a solid, level base which matches or exceeds the building’s footprint in size. Not only does this save you money in the long term by extending the life of your garden room, but it also provides protection against damaging elements like insects and ground water. Additionally, for convenient access and future maintenance, ensure you leave at least 60cm of free space around the building, free from any obstructions. This clearance allows for smooth construction and makes it easier to navigate around the structure during future maintenance.

For those skilled in DIY, our range of DIY garden rooms are an excellent choice! These buildings are supplied with in-depth, comprehensive instructions and step-by-step videos to assist in the construction. Prefer a hassle-free installation? Our other garden room ranges come with home installation as standard. Our expert installers ensure your garden room is constructed to the highest standards, taking care of every detail. Plus, they’ll tidy up any leftover debris, leaving you to enjoy your brand new garden room in peace!

9. Installing utilities

Whatever your garden room’s purpose, it may be beneficial to install facilities such as electric power, water, or drainage. These additions boost the building’s versatility, making it perfect for a home office, personal gym or entertaining space. Ensure that these facilities are installed by qualified, competent tradespeople, and always check with building regulations and your local planning office before beginning work.


For safety and building regulations, it is essential to have a qualified electrician handle the electricity installation for your garden room. You can prepare for the process by digging necessary trenches to lead the cables and marking out the proposed route. Connecting electricity to your garden room opens up a multitude of opportunities to reinvent your space. Additions such as lighting and plug sockets are essential for a functional home office or entertainment space, and offer versatility for future renovations.


Uninterrupted internet connectivity is a must for remote workers or business owners working from their garden room. There are a few ways to connect the internet to your garden building, considering your garden and home setup. Explore options like extending your home WiFi connection to reach your garden room, either directly or with the help of a signal booster. Keep in mind that insulation and double glazing may impact the signal strength from your house. For a more reliable connection, another option is to run an ethernet cable alongside your electric supply. This ensures a stable and consistent internet connection for seamless work and productivity.


Prevent leaks and potential damage in your garden room by enlisting a qualified plumber to install water pipes. You can prepare for the task by digging the trench yourself, just make sure to consult a plumber first for guidance. Ensure the safety of your water supply by maintaining a minimum distance of 350mm from other pipes and wires. Make sure to locate existing services beforehand to avoid any conflicts. Additionally, water pipes should be installed below the frost line, which means a minimum depth of 750mm. Line the bottom of the trench with builder’s sand to provide a soft base for the pipes and cover up any sharp stones that may cause damage.


The easiest and most permanent drainage solution is to make a connection to your house’s mains drainage system. This is the best option if you are installing water or a bathroom in your garden room. However, if your building is located below the level of existing drains, you will need a domestic pumping station which requires a power supply.

10. Maintenance

Regular maintenance is essential to ensure your garden room remains functional and in good condition. Mercia’s insulated garden rooms are supplied with a 10 year anti-rot guarantee, providing it is treated with a wood preservative and waterproofing topcoat after installation and annually thereafter. To maintain the building between treatments, it is recommended to regularly clear any debris away from the building and check for damp or mould. Efficient maintenance of your garden room will ensure its longevity and functionality, so it can be utilised and enjoyed for years to come.

Share on

You may also like

  • Buying Guide - Summerhouses
    By Marketing Mercia

    Buying Guide - Summerhouses

    A summerhouse adds a captivating centrepiece to your garden and offers a comfortable, sheltered space for you to work, relax, or entertain while enjoying scenic views of your garden. With...

  • Buying Guide - Playhouses
    By Marketing Mercia

    Buying Guide - Playhouses

    Playhouses provide children with a dedicated space where they can unleash their imagination and enjoy the great outdoors. With so many design choices available, it can be difficult to decide...

  • Buying Guide - Log Cabins
    By Marketing Mercia

    Buying Guide - Log Cabins

    An affordable alternative to costly home extensions, log cabins are practical, adaptable and versatile. Constructed using thick, interlocking log boards, our cabins provide a robust and resilient structure for year-round...