3.00m x 3.00m Mercia Self-Build Insulated Garden Room

professional range
click to enlarge
3.00m x 3.00m Mercia Self Build Insulated Garden Room - in situ, doors open
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - in situ, doors open
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - in situ, doors closed
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - in situ, top view
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - isolated angle view, doors open
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - isolated angle view, doors closed
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - isolated front view
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - isolated side view
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - isolated side angle view
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - isolated internal view
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - isolated door view
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - isolated internal door view
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - dimensions
  • 3.00m x 3.00m Mercia Self Build Insulated Garden Room - footprint

3.00m x 3.00m Mercia Self-Build Insulated Garden Room

NEW - Interest Free Credit
NEW - Guarantee - 10 year - gold

Product Code - 20040192

write the first review

Usually delivered: 10-15 Working Days.

excludes installation option

Your choices:

  • 3.00m x 3.00m Mercia Self-Build Insulated Garden Room£6,499.99


            Do you want to add a modern and luxurious extension to your home? The Mercia 3m x 3m Insulated Garden Room is the perfect solution. The compact garden pod has a contemporary design that creates an airy feel, bringing the beauty of nature into the space.

            Featuring a flat roof, double-glazed windows, two top-opening side windows, one fixed front window and double doors, the garden room provides a bright space you can use in many ways. The innovative design ensures that you can build it yourself.

            The versatile garden room can be used as a garden office, guest room, or entertaining outdoor area. The insulated walls, roof, and floor make it cosy and comfortable for year-round use.

            Natural light floods the room through the large double doors and double-glazed windows, creating a bright and airy space. This garden room is perfect for all seasons, allowing you to open it up on warm summer days or create a snug glazed garden room by closing the doors and windows in colder weather.

            Made from high-quality materials and finished to a superior standard, the self-build garden room is one of the best models on the market. The easy-to-follow instructions and clever design make it simple to build yourself. 

            Available in: Mercia Self Building Insulated Garden Room 2m x 3m, 3m x 3m,3m x 2m, 4m x 2m, and 4m x 3m


            Guarantee - 10-year anti-rot

            Walls -  72mm thick double-skinned insulated walls (made up of 12mm Tongue and Groove, 72mm Framing, EcoQuilt Insulation and 16mm Shiplap+ Cladding)

            Floor - high-quality 16mm planed tongue and groove and insulated with Air Tec

            Roof - flat roof constructed with Eco-quilt multi-foil insulation, 9mm OSB and 12mm tongue and groove with rubber EPDM roof covering

            Windows and Doors - 2 x 14mm agon filled double-glazed windows

            Doors - double doors 

            Treatment - untreated (application of preservative and waterproof coat required)

            Make the Most of Your Garden Room:

            Small garden rooms offer an ideal solution if you need extra space but lack room to spare in your home. The Mercia 3m x 3m Self Build Garden Room is a year-round option catering to all your needs, whether you want a garden office, guest room, or outdoor entertainment space.

            The garden room's bright and airy interior creates a comfortable and inviting atmosphere for many activities. For those in need of a garden gym, the size of this garden room is perfect for workout equipment. You can make it an outdoor entertainment space by adding a sofa, dining table, and chairs to accommodate all weather conditions.

            With its modern design, this garden room is the perfect addition to your home. Its compact size makes it an excellent option for a small garden.

            About Your Order:

            The Mercia Self Build 3m x 3m is a UK-made garden room that features FSC® certified timber. High-quality timbers are used throughout the construction of the garden building. It’s a self-build garden pod designed to make it simple to construct yourself. The garden room is supplied untreated and will need an application of wood preservative immediately after installation. 

            Please note: Images may show some garden rooms painted and may depict furnishings and accessories; these are for illustration purposes only and are not included with your order.

            Garden Room Aftercare:

            The 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 summerhouse, 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.

            It is recommended that the floor of this garden room is further covered by either carpet or laminate to reduce wear on the matchboards.

            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 base is required to install your Insulated Garden Room. You can contact us for more information on building a garden room base.

            Before the Garden Room installation, ensure 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. There must ne a minimum of 60cm space around the surrounding of the building for installation. 

            About Mercia:

            Mercia Garden Products is 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 FSC® certified, 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.


            ALL DELIVERIES ARE DELIVERED TO KERBSIDE OR DRIVEWAY. This product is delivered flat packed direct to your home, and are supplied with a set of instructions to support assembly.


            The manufacturer's delivery team will get in touch with you to provide a delivery date. Delivery service is generally available in most areas, and you'll discover that the majority of UK postcodes qualify for FREE delivery. However, certain regions may require an additional delivery surcharge, and a few postcodes might not be eligible for delivery at all. When you enter your postcode above, you will be promptly notified if your area incurs a surcharge or if delivery is unavailable in your location

            Prior to Delivery

            On the day of your scheduled delivery, you will receive a text message in the morning containing an estimated 2-hour delivery window (please note that this update can only be provided if a mobile number has been provided in the billing address section during checkout). Additionally, you will receive a link to the manufacturer's delivery portal, where you can track the progress of your order.

            Please note that lead times are calculated based on working days (Monday to Friday) and do not include Bank Holidays. These estimated lead times are provided by the manufacturer. In certain remote areas, delivery may take slightly longer.

            Upon Delivery

            Your order will be delivered either to the kerbside or driveway using a 3.5T, 7.5T, or 18T lorry. For safety and insurance reasons, the driver is unable to carry your goods to the rear of your property. However, upon request, they may place the product at the side of the house if there are no access or restriction issues. Our priority is to avoid any potential damage to your property by delivering to a safe location. Please note that we cannot enter your property during the delivery process.

            We strongly advise against arranging for a third party to install the building before it has been delivered and checked for all the necessary parts. We cannot accept liability for any costs incurred by third parties.


            Please note: all imperial measurements are approximate, and the Mercia Insulated Garden Rooms are made from metric measurements. We would recommend that the base is at least 50mm bigger in each direction.

            Product Name:
            3.00m x 3.00m Mercia Self-Build Insulated Garden Room
            Optional Installation:
            3.17m (7'4")
            3.35m (10'11")
            Footprint Width:
            3.14m (10'4")
            Footprint Depth:
            3.14m (10'4")
            Footprint Width (Internal):
            3.00m (9'10")
            Footprint Depth (Internal):
            3.00m (9'10")
            Height to Ridge:
            2.37m (7'9")
            Height to Eaves:
            2.20m (7'3")
            72mm Double skinned insulated walls (comprises: internal 12mm tongue and groove + 72mm framing + EcoQuilt Insulation and external 16mm Shiplap+ cladding)
            Floor Material
            16mm Planed tongue and groove with Air Tec Insulation between the bearers
            Floor Thickness:
            16mm Tongue and groove
            Floor Joists:
            44mm x 58mm
            Floor Joist Direction:
            Left to right
            Roof Type:
            Pent Roof
            Roofing Felt:
            EPDM roof (durable synthetic rubber)
            Roof Material:
            Eco-quilt multi-foil insulation, 9mm OSB and 12mm tongue and groove with rubber EPDM roof covering
            Roof Thickness:
            Roof Joists:
            44mm x 44mm
            Double door
            Door Height:
            1.96m (6'5") - including framing
            Door Width:
            1.62m (5'4") - including framing
            Door Lock System:
            Door handle and mortise lock (keys supplied)
            Number of Windows:
            Front width: 1 x Fixed window
            Depth: 2 x top opening window
            Window(s) and Door location:
            Front width: Window and door can be reversed
            Window Material:
            14mm Argon-Filled, double glazing
            Window Height:
            1.96m (6'5") - including framing
            Window Width:
            0.76m (2'6") - including framing
            Optional Roofing Felt Tiles:
            Optional Base (to be used instead of a concrete base)
            Untreated timber (must be annually treated with a high quality spirit based wood preservative and a waterproof treatment)
            Recommended Treatment:
            Protek Range (please click here)
            Energy Rating for Building:
            Information not available
            Manufacturer's Guarantee:
            10 Year Anti-Rot Guarantee
            FSC Certified:
            Free Delivery*:
            Product Code:
            Manufacturer Code:
            EAN Number:
            Mercia Garden Products
            Country of Origin:
            United Kingdom
            Click to View Alternative Sizes:
            2mx3m, 3mx2m, 4mx2m, 4mx3m


            Create the perfect extension for your home with this 3m x 3m Self Build Garden Room. The insulated garden pod is designed for all-year use. The key features include: 

            • Simple design for easy self-assembly
            • 72mm Thick Double Skinned Walls
            • Fully insulated roof, floor and walls
            • Interlocking tongue and groove roof and floor
            • 14mm double-glazed with 2 top opening side windows and 1 fixed window
            • 10-year anti-rot guarantee