The Mercia Thoresby Premium Insulated Garden Room 4m x 3m
Key Features
Bespoke and Made to Measure

Contact our Sales Teams for more information on our bespoke service
More Info
Usually delivered: 3 - 6 Weeks.
Description
The Mercia Thoresby 4m x 3m Insulated Garden Room with veranda is a modern space with a spacious design. The reverse apex roof, double glazed windows, and double doors also double glazed make this feel like a luxurious garden room. Free installation is included; place your order, and get ready to enjoy your new garden building.
This modern timber garden room with a veranda will fit many gardens. The open-plan room allows you to furnish it in any way you want. Make it your luxury garden escape with comfy sofas, use bedroom furniture to make it a spare room for guests, or use it as a garden office. Classed as both modern and traditional, the reverse apex design provides a sheltered veranda on the front, perfect for rainy days. The walls are designed with a panel to conceal any electrics you may want to add. Mercia produces some of the best wooden garden rooms you can buy; you will enjoy this new addition for many years.
The french double glazed doors and double-glazed windows make the luxury garden room bright and light. The reverse apex roof creates an elevated ceiling ridge, making the inside area feel big, and you can add feature lights. The roof is protected by an EPDM waterproof rubber membrane designed to last 50 years.
The premium finishing touches and traditional design of the Mercia Thoresby make this one of the best insulated garden rooms. Come and see the incredible build quality for yourself by visiting our Nottingham showroom, where you can take a walk around a Mercia garden room.
Also available:
Mercia Thoresby 5m x 3m Insulated Garden Room with Veranda
Features:
Installation - Included in the price
Guarantee - 10-year anti-rot
Wall - 100mm Double skinned walls insulated (with internal 12mm tongue and groove + 72mm framing + external 16mm Shiplap+ and EcoQuilt Insulation)
Floor - 16mm Tongue and groove floor with Air Tec Insulation between the bearers
Roof - reverse apex roof 158mm (including framework) tongue and groove roof with EcoQuilt Insulation covered with EPDM rubber roof
Windows - 4 double glazed windows include 2 top opening windows
Doors - Double glazed French doors
Treatment - untreated (application of preservative and waterproof coat required)
Make the Most of Your Garden Room:
The Mercia Thoresby 4m x 3m Insulated Garden Room with Veranda lets you add more space that you can use in a variety of ways. This year-round garden room is versatile and comfortable for all seasons, thanks to the insulated walls, roof, and floor. The high ceiling of the reverse apex roof makes the inside feel spacious, so it’s a great place to work out or use as a garden yoga room. The bright interior makes it a luxury garden office. There is plenty of room for adding a bed and other furniture for a guest room. If you want an outdoor entertainment space for all weathers, add some chairs and a dining table. It’s a space you and the whole family can enjoy.
About Your Order:
The Mercia Thoresby is a UK-made garden room that features sustainably sourced timber. High-quality timbers are used throughout the construction of the garden building. A team of professional installers installs Mercia timber garden rooms. The garden room is supplied untreated and will need an application of wood preservative immediately after installation.
Please note: Images may show the garden room painted and may depict furnishings and accessories; these are for illustration purposes only and are not included with your order.
Professional Home Installation – Included as Standard
From start to finish, we make the process effortless. Our expert installation service is included in the price of your building, so you can simply sit back and watch your new retreat take shape.
On the day, our skilled installers will arrive ready to build your garden room with precision and care. Once complete, they’ll leave everything spotless – so all that’s left for you to do is step inside and enjoy your beautiful new space.
Fully Insulated Design
This Insulated Garden Room is built with fully insulated walls, roof, and floor to ensure year-round comfort keeping the space warm in winter and cool in summer.
The Sherwood Range features 100mm thick walls which are double skinned with EcoQuilt insulation layered between the timber cladding. The same high-performance EcoQuilt insulation is also used in the roof. Made in the UK, EcoQuilt is a multi-foil insulation that incorporates an effective vapour control layer, protecting your garden room from damp and moisture.
For the floor, we use AirTec insulation, designed with a bubble structure that traps air, reducing heat loss by up to 50%.
EPDM Rubber Roof
Enhance the durability and weather resistance of your Mercia garden room with our high-quality EPDM roofing solutions. The building comes with EPDM roof covering as standard. Designed to provide superior protection, EPDM is a versatile and long-lasting material that ensures your timber structures remain secure against the elements. Its strong waterproof properties, combined with resistance to UV rays and temperature fluctuations, make it an ideal choice for outdoor use.
Customisable to Suit Your Style
Designed with flexibility in mind, The Sherwood garden room is available in a range of sizes and style, that can be tailored to suit your exact needs. Prefer extra windows for more natural light? Need an extra single or double door? No problem. Speak to our friendly team, we’ll work with you to create a layout that’s just right for you. Your perfect garden room, your way.
Garden Room Aftercare
The timber insulated garden room is supplied untreated. You must apply a preservative and waterproofing topcoat immediately after installation. Using the treatment after installation, followed by consistent annual treatment of the garden room, will maintain the high-quality finish and is a requirement of the 10-year anti-rot guarantee. A 1-year manufacturer's warranty is included as standard.
To treat the garden room, elbec recommends Protek wood treatment. Browse our Protek Royal Exterior Wood Finish Paint range to find the best paint colour to add your own personalised finish. We have selected some of the best-selling Protek Royal Colours as an option on this page, as well as the highly recommended Protek Wood Preserver++
Does A Garden Room Require Planning Permission?
The garden building designs have been created to adhere to planning permission guidelines. However, we cannot guarantee that you will not need planning permission for a garden room. We advise checking with your local authorities before constructing your garden buildings.
What Garden Room Base Do I Need?
A flat, level solid base made of either concrete or concrete slabs is required for the installation of your Insulated Garden Room. You can purchase the Mercia Elite Timber Base With Ground Screws. For more information on how to build a garden room base, you can contact us.
Prior to the Garden Room installation, be sure to check the base is level in all directions. If the base is not level, it will cause the building to twist and warp with the natural movement of the timber. It’s essential to adjust your base accordingly to achieve this before the installation process begins.
Delivery And Installation?
Since this building includes free professional installation, there’s hardly any effort required on your part!
You will need to ensure there is a 24” clearance all the way around the building and have the area cleared and ready on the day. This will allow for the building to be assembled and for you to be able to treat the building.
Note: The installation team will not dismantle or remove any old buildings.
Once your order is placed, the manufacturer’s installation team will be in touch with a short pre-installation questionnaire. This helps us confirm that the site for your new Insulated Garden Room is ready, making sure everything runs smoothly on installation day.
After the foundation is set and access to your garden is clear, our installers will take care of the rest!
About Mercia:
Mercia Garden Products is proud to be a British business with over 140 years of experience. They offer a variety of products ranging from traditional summerhouses and log cabins to greenhouses and fencing and garden storage solutions. All their products are manufactured in the UK using sustainably sourced timber, ethically sourced materials in their products and the most advanced manufacturing techniques. Mercia focuses on innovating and improving its products whilst maintaining customer satisfaction, including ensuring safety for both customers and staff.
Delivery
Delivery & Professional Installation
Your new building includes complimentary installation, which means the hard work is taken care of for you.
Your order is delivered on either a 3.5T, 7.5T or 18T Lorry. You will be contacted within the delivery timescale and given a date for assembly.
Once your order is confirmed, we’ll send you a quick pre-installation questionnaire. This helps us confirm that the space where your Insulated Garden Room will be placed is suitable so that everything runs smoothly on installation day.
Before our team arrives, you’ll just need to ensure there’s a solid, level base ready. If you’ve chosen to prepare your own base, we recommend either a poured concrete foundation or sturdy concrete slabs. Alternatively, you can opt for our Elite Timber Base upgrade, and we’ll handle that for you.
After confirming that the base and access to your garden meet requirements, we’ll get in touch to schedule a convenient delivery and installation date.
Delivery Timescales
These depend on the postal code and confirmation that the base is suitable.
Specification
0.49m (1'7") - Veranda Depth
3.68m (12'1") - overall
1.85m (6'1") - door aperture
0.76m (2'6" - One door open) - aperture
1.53m (5' - Both doors open)
2 x fixed windows
1.71m (5'7") - window glazing
0.60m (1'12") - window glazing
Quickview
The 4m x 3m Mercia Thoresby Insulated Garden Room with Veranda is designed for all-year use, making it perfect for a garden office or guest space. It is made with insulated walls containing EcoQuilt multi-foil insulation for comfort in any weather. The key features include:
- Free home installation
- Part of the Premier Sherwood Collection – timeless Nordic luxury
- Configurable doors and windows – you decide!
- Double-glazed windows and doors
- Insulated walls, roof, and floor with EPDM roof covering
- Customisable design
- 10-year anti-rot guarantee