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Detailed Specification

Please note: all imperial measurements are approximate and the Mercia Insulated Garden Room is made from metric measurements.  We would recommend that the base is at least 200mm bigger in each direction.

Product Name: 5.00m x 3.00m Mercia Insulated Garden Room
Footprint (Front Width x Depth): 5.10m x 3.10m (16'9" x 10'2") (excluding roof overhang) and 5.20m x 3.90m (17'1" x 12'10") (includes roof overhang)  
Height to Ridge: 2.40m (7'9")
Height to Eaves: 2.20m (7'2")
Walls: 72mm Double Skinnned Walls Insulated (with internal 12mm Tongue and Groove + EcoQuilt Insulation and external 16mm Shiplap +)
Framing: 45mm x 45mm (1 3/4' x 1 3/4')
Door: Double Door
Door Opening (Height x Width): 1.85mm x 1.50mm (6'1" x 4'11")
Door Lock: Door Handle and Mortise Lock (Keys Provided)
Roof Type: Pent Roof
Roof: Insulated Roof (with internal 12mm Tongue and Groove + EcoQuilt Insulation and 9mm OSB Board)
Roofing Felt: EPDM Roof (Durable synthetic rubber)
Floor: 16mm Tongue and Groove Matchboard with EcoQuilt insulation between the bearers
Floor Joists: 48mm x 48mm (2" x 2")
Floor Joists Direction: Front to Back
Window(s): 4 x Windows (2 x Fixed Full Glazed Window and  2 x Fixed Windows with Small Top Opening Window)
Interchangeable: No
Window Glazing Material: Argon-Filled, Double Glazing
Windowless Option Available: No
Treatment: Untreated Timber
Portabases Available: N/A
Manufacturer's Guarantee: 10 Year Anti-Rot Guarantee
FSC Certified: Yes
Free Delivery: Yes*
Assembly Available: Provided Free Of Charge
EAN Number: 5029442087801
Recommended Treatment: Protek Range (please click here) Quantity: External = 6.75L, Internal 10.75L and Floor 4L (base on two coats)
Manufacturer: Mercia


Looking for a way to expand on the usable space you have at home? Perhaps you’re after a recreation room, a home office, a home gym or even a guest or spare bedroom but simply don’t have the space indoors? Then the 17 x 10 Insulated Garden Room from Mercia could be the perfect solution. A spacious, versatile and customisable building that is well-insulated from the elements, it gives you a way of taking advantage of otherwise unused garden space all-year-round for whatever purpose you have in mind.

At elbec, we are certain an Insulated Garden Room will provide you with exactly the space you need if you are running out of room in your home and moving house or building a traditional extension are unrealistic options.

Ways to Make the Most of Your Insulated Garden Room

There are loads of ways you can make the most of the fantastic new space the Insulated Garden Room provides. As a place to relax in your spare time while enjoying the beauty of the outdoors, it is hard to beat a Garden Room as a flexible living space. A recreation area, a games room, an entertainment centre or a dining room, you will have a bright, spacious and airy place to spend your free time in the stunning surroundings of your garden. Moreover, working from home is increasingly becoming an attractive option for many, so a popular choice is to use the Insulated Garden Room as a home office. We often hear that the peaceful outdoor atmosphere, away from possible distractions in the home, is ideal for concentrating on work. Its wall insulation system is what gives the Insulated Garden room its year round usability and what also makes it suitable as a guest or spare bedroom. Increasingly, we see people opting to use their garden room as somewhere for regular visitors to stay or even as a permanent room for a family member thanks to the fact that it remains cosy in the colder months and cool in the summer. Finally, as a place for our customers’ favourite spare time activities or hobbies, an Insulated Garden Room is a superb space. Whether you’re after a space to set up an airy home gym, an inspirational art studio or perhaps even a home bar perfect for entertaining guests, you’ll love making the most of your Garden Room, however you decide to use it.

Why the Insulated Garden Room Could be Perfect for You

The Insulated Garden Room boasts a simple yet stylish design that delights lovers of a contemporary look. The Garden Room’s pent roof really gives it that modern look while also providing excellent water run-off to the rear. The roof also has a charming overhang, providing a valuable sheltered area as well as an appealing design feature. The real beauty of the Insulated Garden Room, however, is that it is a modular design. This means the panels are interchangeable, so you can locate the windows and doors wherever you like on the building. You know your garden best, and the flexibility this gives you means you can choose the layout that is right for your garden. Whether it’s to get the best views possible when looking out, or perhaps you want maximise the sunlight that can flood your building, you can decide on the best way to achieve it. Two of the supplied windows also have a top opening, so you can control the temperature inside your Garden Room with ease. Our customers often like to personalise their Insulated Garden Rooms. Many manufacturers recommend using Protek Paint, which is available from elbec in a wide variety of colours. By using Protek Royal Exterior, you can make your Insulated Garden Room look exactly how you choose, while adding essential protection to the timber.


The Insulated Garden Room boasts a number of features that show its quality. It is supplied as standard with an EPDM (Ethylene Propylene Diene Methylene) rubber roofing, which is a synthetic rubber that is extremely durable, heat and weather resistant and provides protection for up to 50 years. This is attached to a double-layer roof which combines a 12mm OSB outer layer with a 12mm tongue and groove inner layer, with insulation in between. This reduces heat loss and provides excellent weather protection.

The 72mm double skinned walls use a 16mm tongue and groove cladding, which is Mercia’s “Shiplap+” cladding. This provides one of the most weather resistant interlocking panels possible. There is also a layer of 12mm shiplap cladding as part of the sturdy, well-insulated wall construction. But the real draw of the Insulated Garden Room is the “EcoQuilt” insulation layer that lies between the two shiplap wall panels. EcoQuilt insulation works as a total Insulation blanket, preventing warmth from escaping the building and reflecting heat back into the Garden Room. This also means that it reflects heat during warmer weather, ensuring the Garden Room is a comfortable temperature, whatever the weather. A robust 45mm framing completes the sturdy structure of the Insulated Garden Room, giving the building excellent strength and durability.

The double doors and windows are double glazed with two 4mm glass panes, and the 6mm gap is argon-filled, providing an extra-snug interior. The modular construction means doors and windows can be moved to wherever you would like on the building as required. Finally, the floor is a hard-wearing 16mm tongue and groove matchboard construction, supported by thick, durable bearers. This will support the weight of heavier items of furniture that you may wish to adorn the Garden Room with. To top it all off, the Insulated Garden Room boasts free installation, meaning all you will have to do is sit back and plan how you want to use your fantastic, new garden building.

About Your Insulated Garden Room Order

If you think that a Mercia Insulated Garden Room would be perfect for you, take a look at our delivery information. If you would like any extra details, feel free to email us to discuss your order and our full range of product options, or better still, give us a call so we can find the perfect garden building to suit your needs.

Alternatively, why not visit us at our Brookfields Garden Centre showsite near Nottingham? One of our helpful advisors will be on hand to show you around or to help guide you through your order in person. Though if there is a particular garden building you would like to see, we recommend contacting us in advance to find out if we have it, or one similar, on site.

The footprint of the external base of this Insulated Garden Room is 3120mm x 5130mm. This measurement excludes roof overhangs. Full measurement details can be found in the detailed specification.

The Mercia Insulated Garden Room is supplied untreated. You must apply a wood treatment to the exterior. Many manufacturers recommend Protek wood treatment, available from elbec in many different colours. This will protect the timber from weathering, making it last longer. The timber treatment will need to be repeated periodically in line with the manufacturer's care instructions.

What is included?

  • Double doors fitted with a mortise lock (keys provided) for extra security.
  • A stylish design with roof overhang and downlights
  • Rigid and weather resistant construction that protects the building
  • 72mm double skinned walls, using 12mm and 16mm cladding
  • 4 x Windows (2 x Fixed Full Glazed Window and  2 x Fixed Windows with Small Top Opening Window)
  • Double glazing on doors and windows, using 14mm argon-filled glazing
  • EPDM Rubber roofing, providing heat and weather resistance to help prevent weather damage and wood rot
  • Uses a wooden interlocking system to provide a more water tight building to protect against the weather
  • A modular design that is customisable
  • Sturdy floor bearers to provide extra support to the building and any extra weight placed within
  • 12mm OSB roof fitted with Insulation and 12mm roof cladding that offers more heat within the building, and protects better against the weather
  • 16mm tongue and groove floor to provide extra sturdiness to the flooring
  • Free installation provided as standard with this item


ALL DELIVERIES ARE DELIVERED TO KERBSIDE OR DRIVEWAY. All of our Mercia products are delivered flat packed other than fence panels (which are delivered fully constructed), direct to your home, and are supplied with a set of instructions to support assembly.

Booking Delivery

You will be required to book your delivery date at the time of placing your order (except for Metal Shed). Our 'Request a Delivery Date' service is available to the majority of areas and you'll find that the majority of the UK postcodes are FREE but some areas may incur a delivery surcharge and some postcodes are not covered at all. Select a 'requested delivery date' by entering your postcode in the 'Request a delivery date' section above. You will also be notified at this time if your area incurs a surcharge or delivery is not covered in your area.

Prior to Delivery

On the morning of your delivery date, you'll be sent an update by text with an estimated 2-hour delivery slot (this update can only be provided where a mobile number has been supplied on the billing address section at the time of checkout) together with a link to the manufacturer delivery portal where you'll be able to track your order.

Please note: Mercia Metal Sheds ONLY - your order is delivered by a courier you will not be notified prior to the delivery. If you are not in on the day of the delivery you will be carded and asked to contact the courier to arrange a new mutual delivery date. The estimated delivery lead time for Mercia's Metal sheds is identified on the product for the metal shed. Lead times are on working days (Monday - Friday) excludes Bank Holidays. These estimated lead times are provided by the manufacturer. Some remote areas will take a little longer.

Upon Delivery

Your order is delivered either kerbside or driveway and will be delivered on either a 3.5T, 7.5T or 18T Lorry. Unfortunately due to health and safety and insurance liabilities the driver will not be able to take your goods around to the back of your property but may upon request place the product at the side of the house if there are no access or restriction issues. We would not risk damaging your property whilst delivering a product to an unsafe location. Unfortunately, we will not be able to go through your property.

We would recommend against arranging for a third party to install the building before it's been delivered and checked that all parts are present, as we cannot be held liable for any third-party costs.


Orders with Assembly 

The lead time for our installation option is around 12 weeks from the date of order. With the installation option, the majority of orders will have their delivery and installation on separate days; there will be a small number of orders which will have delivery and installation on the same day. You will be advised by the manufacturer's installation team which category your order falls into.

Depending on the installation option for your order, you will be contacted within the delivery timescale and given a date for either delivery/assembly on the same date or a separate date for delivery and assembly.

5.00m x 3.00m Mercia Insulated Garden Room

NEW - Guarantee - 10 year - gold
NEW - Installation - Free Installation

Product code - 20040138


Description Information

Offering loads of usable interior space, the 17 x 10 Mercia Insulated Garden Room could provide you with a valuable new room for your home if a traditional extension isn’t and option. A recreation room, a home office, a home gym or even a guest or spare bedroom, you can take advantage of this spacious garden building all year round. The key features include:

  • 72mm thick, double-clad walls fitted with innovative and effective “EcoQuilt” insulation
  • Long-lasting EPDM rubber roof and 14mm double glazed windows provide excellent protection from the elements
  • Installation is included free of charge as part of the price of your Garden Room

View full specification Delivery

Usually delivered: 30 Working Days.

Note: Currently not available for delivery to Offshore Post Codes.

excludes installation option

Your choices:

  • 5.00m x 3.00m Mercia Insulated Garden Room£11,749.99