Buying Guide
Insulated Garden Rooms
An insulated garden room is a stylish way to bring extra space into your home, offering a warm, versatile area for work, relaxation, or hobbies. All without the need for a costly extension.
Read the Ultimate Guide to Buying an Insulated Garden Room to help you choose the ideal design for your home and lifestyle. This guide walks you through all the key options so you can make a confident choice and enjoy your new space all year round.
An insulated garden room from Mercia is the perfect way to bring flexible living space to your home whether you’re creating a stylish home office, a peaceful gym, a place to unwind, or even a comfortable guest suite.
Available in sizes from 2m x 3m up to 6m x 4m, each design features a sleek 2.5m flat roof that typically avoids the need for planning permission.
With so many configurations and features to choose from, it can be difficult to know where to start. That’s why we’ve created this in-depth guide, packed with expert advice on design, insulation, and setup, to help you find the garden room that’s just right for you.
Purpose
Office Space
An insulated garden room makes the perfect home office, offering a quiet, efficient workspace just steps from your house. Though it’s worth checking local regulations, as business use may affect rates or mortgage terms.
Guest Suite
A garden room offers the perfect extra space. Whether as a comfortable guest room for visitors or a private retreat that gives everyone a little more space and independence.
Home Gym
A garden room gym gives you the perfect space to work out in privacy, with plenty of room for equipment and even a peaceful spot for yoga surrounded by nature.
Craft Room
A garden room is the ideal creative retreat, offering the space, light, and tranquillity you need to enjoy crafts or hobbies like sewing, painting, and drawing without ever having to pack away your work.
Entertaining Space
With an insulated garden room, you can entertain in style all year round. Enjoying the feeling of dining outdoors while staying warm and dry, whatever the weather.
Components
Modular Panels
Constructed from precision-engineered, ready-insulated panels, our garden rooms combine strength, quality, and ease of installation. Each wall features 16mm shiplap cladding externally and 12mm interlocking cladding internally, providing a durable and refined finish. The 45mm framing delivers exceptional rigidity and stability, while the Premium Sherwood Range enhances this further with 72mm framing for superior strength and insulation. To ensure a seamless experience, our professional installation team will assemble your garden room on-site at no additional cost, guaranteeing a high-quality finish from start to completion.
Insulation
We use EcoQuilt insulation within our garden room panels, a high-performance, foil-coated, breathable membrane designed to deliver exceptional thermal efficiency without reducing internal space. Comprising six layers of thermowadding and reflective foil, EcoQuilt acts as both a vapour control layer and an insulating barrier, providing thermal values equivalent to over 100mm of traditional fibre insulation, yet measuring only 6mm thick. This innovative system keeps your garden room comfortable and energy-efficient all year round. To maximise performance, every garden room is also fully insulated in the walls, floor, and ceiling.
Tongue and Groove Floor
As you’d expect from a durable, long-lasting garden building, the floor of your new office or hobby room is constructed from 16mm tongue and groove matchboard, securely fitted onto a robust timber frame for exceptional strength and stability. To ensure lasting performance, your garden room should be installed on a solid, level concrete slab base. If you’re unsure how to prepare one, it’s best to consult a local builder for professional advice and guidance.
Pent Roofs
A pent roof gives your garden room a sleek, modern appearance while ensuring efficient rainwater drainage to the rear. The design includes a generous front overhang for added protection from the elements. Constructed from durable OSB and lined with 12mm internal matchboard, the roof is finished with high-performance EPDM, a long-lasting, rubberised material with heat-welded seams for superior weather resistance and durability.
Glazing Options
One of the key advantages of a garden room is the abundance of natural light it provides, creating a bright and inviting space whether you’re working, relaxing, or entertaining. Thanks to its modular design, you can choose exactly where your windows and doors are positioned to suit your layout and preferences. Every insulated garden room is fitted with 14mm double-glazed, argon-filled windows as standard, offering excellent insulation to keep the space warm year-round while providing enhanced strength and security.
Upgrade to UPVC
Upgrade your Insulated Garden Room with low-maintenance UPVC windows and doors, combining durability, energy efficiency, and a sleek finish. Available for all Sherwood buildings in white, oak, and anthracite grey, this option enhances both the style and long-term performance of your building.
Premium Insulated Garden Rooms With UPVC
Installation
Although most insulated garden rooms fall under permitted development and don’t usually require planning permission, there are still a few key rules and practical considerations to keep in mind. Always double-check with your local planning authority before starting your project.
- Your garden room and other outbuildings must not take up more than half your available garden space and should be single-storey with a maximum eaves height of 2.5m.
- Buildings within 2m of a boundary must not exceed 2.5m in total height, and none can be built in front of your home’s main elevation.
- Position your room to make the most of sunlight (south or west-facing) and keep it clear of trees and walls for maintenance and good drainage.
- If you plan to use your building for overnight stays or install mains utilities, you’ll need to comply with building regulations.
The Sherwood Range
As standard The Sherwood Range includes installation from our team of qualified professionals. So all you need to do is sit back and await your new IGR.
DIY IGRs
Save on installation costs by building your own insulated garden room with the Mercia DIY range. Follow clear instructions and all fixtures included, it’s a straightforward project for two people with basic DIY skills.
Utilities
Adding utilities to your insulated garden room can greatly increase its functionality and comfort, but all work must be carried out by qualified professionals. Here are a few key things to keep in mind when planning for mains water, drainage, and electricity.
Water
A qualified plumber should always handle the connection of your garden room to the mains water supply, though you can cut costs by preparing the groundwork yourself. If you decide to dig the trench, keep these key points in mind:
- Always locate and mark other underground services before digging to avoid damage.
- Keep at least 350mm distance between your water pipe and any other service lines.
- Bury the pipe a minimum of 750mm below ground to prevent freezing during cold weather.
Drains
Unless you intend to install a separate septic tank (which can be costly) the simplest way to manage wastewater from your garden room is to connect it directly to the mains drainage system. The waste pipe can be laid alongside your fresh water pipe, but if your garden room sits below the level of the main sewer, you’ll need to include a pump to ensure proper flow.
Electricity
Installing mains electricity in your garden room must always be carried out by a qualified electrician. Because running 240V power is notifiable under Section P of the Building Regulations, you’ll need to submit plans or a building notice before work begins, and the completed installation must be signed off by a registered competent person or building control body.
Alternatively, if you prefer an off-grid setup, solar panels are a great eco-friendly option to power lighting, heating, or office equipment.
Internet
Getting online in your garden room is easier than ever, with several options depending on your setup and budget. Before deciding, it’s worth checking how far your home router reaches and what solutions best fit your needs:
- Check your router’s range and explore Wi-Fi extenders or mesh systems to boost coverage.
- Run ethernet cables alongside your mains supply for a fast and stable connection.
- Use powerline adapters to send internet signals through your building’s electrical wiring.
- Rely on mobile tethering or a dedicated 4G/5G router for a flexible, cable-free option.
Maintenance
All our insulated garden rooms include a 10-year anti-rot guarantee, but regular maintenance is key to keeping them looking their best. Treat your garden room annually with a high-quality wood treatment to protect it from the elements and extend its life.
Oil-based treatments: Deeply penetrate the wood for excellent protection and a smooth, even finish.
Water-based treatments: Offer great resistance to mildew and longer-lasting colour with fewer fumes.
Painted finishes: Available in oil or water-based options, providing both protection and a modern, stylish look.
Deciding
Whether you’re after a compact home office, a spacious gym, a relaxing retreat, or a stylish space for entertaining, a Mercia insulated garden room offers the perfect solution for flexible living. Available in sizes from 2m x 3m up to 6m x 4m, each design features a sleek 2.5m flat roof that typically avoids the need for planning permission. Fully insulated and double glazed, our garden rooms are custom-made to suit your lifestyle providing comfort, versatility, and year-round use for work, rest, or play.